Consideration of the Optimal Surgical Procedure Based on the Risk of Recurrence in Clinical Stage 0 or IA Lung Adenocarcinoma

Consideration of the Optimal Surgical Procedure Based on the Risk of Recurrence in Clinical Stage 0 or IA Lung Adenocarcinoma | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research article Consideration of the Optimal Surgical Procedure Based on the Risk of Recurrence in Clinical Stage 0 or IA Lung Adenocarcinoma Tomoyoshi Takenaka, Tetsuzo Tagawa, Naoki Hartake, Fumihiko Kinoshita, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-330128/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Jan, 2022 Read the published version in Anticancer Research → Version 1 posted You are reading this latest preprint version Abstract Background Although sublobar resection is widely performed for early-stage non-small cell lung cancer, what kind of patients should be actively indicated for sublobar resection has not yet been established according to 8th edition of tumor node metastasis classification (TNM). We evaluated the computed tomography (CT) features and optimal surgical procedures of clinical stage 0 or IA adenocarcinoma from the perspective of recurrence. Methods We retrospectively investigated 508 lung adenocarcinoma diagnosed as c-stage 0 or IA in the 8th edition of TNM classification. A survival analysis was performed according to the clinical T descriptor, CT features and surgical procedures. Results The tumors were classified as follows: 74 with pure ground glass opacity (GGO), 237 part-solid tumors and 197 solid tumors. The types of surgical procedures were lobectomy (n = 328), segmentectomy (n = 73) and wedge resection (n = 107). Clinical T descriptors were cTis in 74 patients, cT1mi in 68 patients, cT1a in 94 patients, cT1b in 181 patients and cT1c in 91 patients. Recurrence was observed 46 cases (9%), including 3 (3.1%) with cT1a, 23 (12.7%) with cT1b and 20 (22.0%) with cT1c. No recurrence was observed in cTis or cT1mi cases. Solid tumors with cT1b recurred more often than part-solid tumors among cT1b cases (6.8% vs. 16.8%) (p = 0.046). There were no marked differences in the recurrence rate between part-solid and solid tumors in the cT1a and cT1c groups. The patients who received sublobar resection developed recurrence more often than the patients who received lobectomy among cT1b cases (10.1% vs. 21.4%) and cT1c cases (18.0% vs. 46.2%) (p = 0.053 and p = 0.023). Conclusions Pure GGO and cT1mi cases should be actively considered for sublobar resection, while cT1b (especially solid cT1b cases) and cT1c cases should be considered for lobectomy to prevent recurrence. Surgery General Surgery lung adenocarcinoma TNM staging surgical resection recurrence Figures Figure 1 Background There were 2.0 million incident cases of lung cancer and 1.7 million deaths in 2016; lung cancer continues to be the most common type of cancer [ 1 ]. However, widespread screening with low-dose helical computed tomography (CT) has led to an improved rate of early detection for small-sized lung cancers [ 2 ]. Since the 1970s, tumor size has been a primary descriptor, and a significant prognostic factor for lung cancer in the tumor, node, metastasis (TNM) classification of the staging system of the Union for International Cancer Control [ 3 ]. In the 8th edition of the TNM classification for non-small cell lung cancer (NSCLC), the cT category is defined by the tumor size, but only the size of the solid component on CT for prognostic stratification [ 4 ]. Recently, several researchers have reported that radiologically determined pure-solid lung cancers without a ground glass opacity (GGO) component exhibit more malignant behavior than the tumors with GGO [ 5 – 7 ]. Thus, whether or not patients with solid tumors should be treated similarly to patients with part-solid tumors with equal-sized solid components is controversial. Although lobectomy is the standard resection approach for patients with clinical stage I NSCLC who can tolerate lobectomy, according to a previous randomized controlled trial comparing lobectomy with sublobar resection including segmentectomy and wide-wedge resection [ 8 ], sublobar resection is widely performed for early-stage NSCLC due to its improved diagnostic ability for cases with a good prognosis [ 9 , 10 ]. According to The Japanese Joint Committee of Lung Cancer Registry reports, 22.7% of cases of lung cancer resection cases received sublobar resection in 2010 [ 10 ]. In addition, a phase III study was conducted to evaluate the non-inferiority of segmentectomy compared with lobectomy in patients with small peripheral NSCLC (≤ 2cm diameter) in Japan and in the United States [ 11 , 12 ]. However, what kind of patients should be actively indicated for sublobar resection has not yet been established. In the present study, we assessed the CT features and optimal surgical procedures for clinical stage 0 or IA adenocarcinoma according to the current staging system from the perspective of recurrence. Methods Patients We included 508 consecutive patients who were diagnosed with clinical stage 0 or IA NSCLC according to the TNM 8th edition, and underwent surgery between January 2009 and December 2018 at our department. Written informed consent was obtained from each patient to use their medical records. This study was approved by the institutional review of board of Kyushu University Hospital (IRB number: 2019 − 232). The perioperative examination Contrast-enhanced CT was routinely performed during each preoperative examination of the entire lung except for contraindicated cases. Images were viewed on standard lung windows (level: −500 to − 700 HU; width: 1500 to 2000 HU). The whole tumor size and solid component size were determined from the maximum diameter of the tumors and the solid part of the tumors, respectively. Tumors were divided into pure GGO, part-solid tumors and solid tumors based on the consolidation tumor ratio (CTR) in thin-section CT: pure GGO, CTR = 0; part-solid, 0 < CTR < 1; solid, CTR = 1. Clinical staging was determined based on the findings of chest and upper abdomen CT, brain CT or magnetic resonance imaging (MRI), radionuclide bone scans and/or with fluorodeoxyglucose-positron emission tomography (FDG-PET). Endobronchial ultrasound mediastinal lymph node biopsies were performed when nodal involvement was suspected. The histologic types of the lung adenocarcinoma were classified according to the International Association for the Study of Lung Cancer /American Thoracic Society/European Society of Thoracic Surgeons classification [ 13 ]. Follow-up examinations were usually conducted every three to four months for the first two years and every three to six months thereafter. Routine follow-up procedures included a physical examination, hematological examination and chest radiography. In addition, chest and abdominal CT were performed at least once a year. If recurrent disease was suspected, further evaluations, such as MRI and FDG-PET were added. Recurrent NSCLC was diagnosed based on physical examinations and diagnostic imaging findings consistent with recurrent disease. When clinically feasible, diagnoses were histologically confirmed. The date of recurrence was defined when recurrence was histologically proven or, in cases that were diagnosed by clinical evidence, when recurrent disease was recognized by the attending physician. Operation Policy With regard to the agreement at our institution, if a tumor was pure GGO or GGO-dominant, the patients actively received sublobar resection, whereas major lung dissection with systematic or selective lymph node dissection was warranted for part-solid or solid tumors. Some patients who were elderly, had a high cardiopulmonary risk or could not tolerate lobectomy for any other reason reluctantly received sublobar resection. Data collection and extraction Demographic, clinical and treatment data were extracted from an institutional database that included all patients who had undergone thoracic surgery. For cases before 2017, clinical T staging was reassigned in accordance with the 8th edition of the TNM classification. Statistical analyses Comparisons of continuous and dichotomous variables between groups were performed with Student’s t -test and the χ 2 -test, respectively. The probability of a survival was estimated by the Kaplan–Meier method. Differences in the survival were evaluated by log-rank tests. The analyses were performed using the JMP software package (version 11, SAS Institute Inc., Cary, North Carolina). P < 0.05 was considered significant. Results The characteristics of the 508 patients are summarized in Table 1 . Preoperative chest CT showed 74 pure GGO cases, 237 part-solid tumors and 197 solid tumors. The types of procedures included lobectomy (n = 328), segmentectomy (n = 73) and wedge resection (n = 107). The median duration of follow-up after surgical resection was 49 months (range: 1–121 months). The mean tumor measurements were a whole tumor size of 18 mm (range: 5 − 30 mm) and solid component size of 12 mm (0–30 mm) (Table 1 ). The clinical T descriptor according to the TNM 8th edition was cTis in 74 patients (15%), cT1mi in 68 patients (13%), cT1a in 94 patients (19%), cT1b in 181 patients (36%), and cT1c in 91 patients (18%) (Table 1 ). Table 1 Patients’ characteristics Variable n = 508 Age (range) (years) 67 (33 to 88) Gender Male 239 (47%) Female 269 (53%) CT features Pure GGO 74 (15%) Part-solid 237 (47%) Solid 197 (39%) Whole tumor size (mean) 5–30 mm (18 mm) Solid component size (mean) 0–30 mm (12 mm) cT descriptor according to TNM 8th edition Tis 74 (15%) T1mi 68 (13%) T1a 94 (19%) T1b 181 (36%) T1c 91 (18%) Surgical procedure Lobectomy 328 (65%) Segmentectomy 73 (14%) Wedge resection 107 (21%) pTNM stage 8th edition Stage 0 35 (7%) Stage IA1 142 (28%) Stage IA2 185 (36%) Stage IA3 51 (10%) Stage IB 50 (10%) Stage II 20 (4%) Stage III 21 (4%) Stage IVa 4 (1%) CT, computed tomography; GGO, ground glass opacity; TNM, tumor node metastases For the entire cohort, the 5-year overall survival (OS) rate was 93.8%, and the 5-year disease-free survival (DFS) rate was 87.5%. Kaplan-Meier analyses of the OS and DFS according to the clinical T descriptors on the 8th edition of the TNM classification are shown in Fig. 1 A and 1 B. The respective 5-year OS and DFS rates by clinical descriptors were as follows: 97.6% and 97.6% in cTis, 95.4% and 95.4% in cT1mi, 96.4% and 93.9% in cT1a, 92.4% and 84.8% in cT1b and 89.2% and 70.8% in cT1c (Fig. 1 A and 1 B). The correlation between the surgical procedure and CT features or clinical T descriptors is shown in Table 2 . The patients with solid tumors or a large number of T descriptors received lobectomy more often than others (p < 0.001 and p < 0.001) (Table 2 ). Table 2 Relationship between CT features, clinical T factor and surgical procedure Variable Lobectomy Sublobar resection (n = 328) (n = 180) p-value CT features Pure GGO 29 (39.2%) 45 (60.8%) p < 0.001 Part-solid 143 (60.1%) 95 (39.9%) Solid 156 (79.6%) 40 (20.4%) cT descriptor according to TNM 8th edition Tis 29 (39.2%) 45 (60.8%) p < 0.001 T1mi 31 (45.6%) 37 (54.4%) T1a 52 (55.3%) 42 (44.7%) T1b 139 (76.8%) 42 (23.2%) T1c 77 (84.6%) 14 (15.4%) CT, computed tomography; GGO, ground glass opacity; TNM, tumor node metastases Recurrence was observed in 46 cases (9%) including 11 patients with part-solid tumors (4.6%) and 35 patients with solid tumors (17.9%) (Table 3 ). Recurrence occurred in 3 patients (3.1%) with cT1a, 23 patients (12.7%) with cT1b and 20 patients (22.0%) with cT1c. No recurrence was observed in pure GGO, cTis or cT1mi cases (Table 3 ). The presence or absence of recurrence and CT features or surgical procedure in cT1a, T1b and cT1c cases is shown in Table 4 . For cT1a cases, the CT features and surgical procedure did not influence the recurrence rate; however, for cT1b cases, solid cases developed recurrence significantly more often than part-solid cases (p = 0.046). Although it was not statistically significant, patients who received sublobar resection developed recurrence more often than the patients who receive lobectomy (p = 0.053). For cT1c cases, there were no significant difference in the recurrence rate between part-solid cases and solid cases; however, the patients who received sublobar resection developed recurrence more often recurrence than the patients who received lobectomy (p = 0.023). Table 3 Recurrence rate according to CT features and clinical T factor Variable Recurrence Not recurrence (n = 46) (n = 462) p-value CT features Pure GGO 0 (0%) 45 (60.8%) p < 0.001 Part-solid 11 (4.6%) 95 (39.9%) Solid 35 (17.9%) 40 (20.4%) cT descriptor according to TNM 8th edition Tis 0 (0%) 74 (100%) p < 0.001 T1mi 0 (0%) 68 (100%) T1a 3 (3.1%) 91 (96.8%) T1b 23 (12.7%) 158 (87.3 %) T1c 20 (22.0%) 71 (78.0%) CT, computed tomography; GGO, ground glass opacity; TNM, tumor node metastases Table 4 Recurrence rate according to tumor morphology and surgical procedures in cT1a, T1b and T1c cases. cT1a cases Recurrence Not recurrence Variable (n = 3) (n = 91) p-value CT features Part-solid 2 (2.5%) 79 (97.5%) p = 0.320 Solid 1 (7.7%) 12 (92.3%) Surgical procedure lobectomy 3 (5.8%) 49 (94.2%) p = 0.114 Sublobar resection 0 (0%) 42 (100%) cT1b cases Recurrence Recurrence (n = 23) (n = 158) CT features Part-solid 5 (6.8%) 69 (93.2%) p = 0.046 Solid 18 (16.8%) 89 (83.2%) Surgical procedure lobectomy 14 (10.1%) 125 (89.9%) p = 0.053 Sublobar resection 9 (21.4%) 33 (78.5%) cT1c cases Recurrence Not recurrence (n = 20) (n = 71) CT features Part-solid 4 (25.0%) 12 (75.0%) p = 0.748 Solid 16 (21.3%) 59 (78.7%) Surgical procedure lobectomy 14 (18.0%) 64 (82.0%) p = 0.023 Sublobar resection 6 (46.2%) 7 (53.8%) CT, computed tomography Discussion According to the 8th edition of the TNM classification for NSCLC, the T classifications of the tumors ≤ 3 in diameters are based only on the size of the solid component on CT or the size of the invasive component at the pathologic examination, as the size of the solid/invasive component is considered to determine the prognosis [ 4 ]. In the present study, we first compared OS and DFS of all cases according to the clinical T factor of the TNM 8th edition in clinical stage 0 or IA lung adenocarcinoma. These results indicated that the prognosis of all cases was well stratified according to the classification in this study. However, on comparing the DFS values for cT1mi and cT1c, the 5-year DFS rate was about 25% different, despite being the same clinical IA stage; therefore, the current treatment strategy, such as the timing of treatment and surgical procedure should be considered carefully. In addition, although this stratification using the classification is useful with regard to the prognosis as well, several issues must be addressed due to switching from the conventional evaluation method involving the maximum tumor diameter. One problems is that the suitability of current treatment strategies, such as limited resection, adjuvant therapy and follow-up, is considered based on the previous staging system. Although lobectomy is the standard procedure for managing early stage NSCLC [ 8 ], sublobar resection, such as segmentectomy and wedge resection, are widely performed for small NSCLC in clinical practice [ 9 , 10 ]. Thus, randomized phase III studies such as Cancer and Leukemia Group B (CALBG) 140503 and Japan Clinical Oncology Group (JCOG) 0802 were conducted in United States and Japan to evaluate the non-inferiority of segmentectomy compared with lobectomy in patients with small peripheral NSCLC. The CALBG and JCOG studies targeted NSCLC patients with a whole tumor size of ≤ 2cm [ 11 , 12 ]. Therefore, the whole tumor size, including ground-glass and lepidic components on radiology and pathology is required in order to evaluate separately from new TNM classification. It is also necessary to consider surgical procedures according to the current staging system; therefore, we evaluated the optimal surgical procedures for clinical stage 0and IA adenocarcinoma according to the CT features and current T descriptors in this study. Our results showed no recurrence in cTis and cT1mi cases, regardless of surgical procedure; therefore, we may actively consider performing sublobar resection for cTis and cT1mi cases. In addition, regarding cT1a cases, only 3% of all such cases experienced recurrence (all 3 recurrent cases received lobectomy); therefore, the indication of those cases for sublobar resection is appropriate. Regarding cT1b and cT1c cases, patients who received sublobar resection experienced recurrence more often than others. Although the recurrence rate of solid tumors was significantly higher than that of part-solid tumors among cT1b cases, no significant difference was observed between part-solid and solid tumors among cT1a and cT1c cases. Several studies have recently indicated that tumors with GGO components have a better prognosis than those without GGO component [ 5 – 7 ]. Fu et al. reported that the presence of GGO components was a strong predictor in patients with invasive pathological stage I NSCLC [ 6 ]. Hattori et al. also reported that the presence of GGO component had a marked impact on the favorable prognosis of small lung adenocarcinoma [ 5 ]. They found that solid tumors with clinical stageIA1, IA2 and IA3 had a significantly worse prognosis than the part-solid tumors of the same clinical stage [ 5 ]. Hattori et al. also reported that segmentectomy and a larger tumor size were independent significant clinical factors of loco-regional recurrence in clinical T1aN0M0 (TNM 7th staging) solid NSCLC [ 14 ]. There has also been a report comparing the prognosis of solid and part-solid tumors subjected to lobectomy. Takenaka et al. reported a study comparing part-solid and solid tumors among clinical stage IA NSCLC patients who received lobectomy [ 15 ]. Although the patients with solid tumors had a significantly worse outcome than those with part-solid tumors in all cases, the propensity-matched analysis detected no significant difference in the survival between the patients with solid and part-solid tumors when matched according to the size of the solid component [ 15 ]. These present and previous findings suggest that, for now, the indications for sublobar resection for solid tumors should be carefully determined, even in cases of small adenocarcinoma. Several limitations associated with the present study warrant mention. First, this study had a retrospective observational design and used a single-institution Japanese database to enroll only patients who had undergone surgical resections. Second, the surgical procedures were selected according to the individual patients and were not randomized. Although the results of Phase III trials are required to establish evidence supporting limited resection for early stage NSCLC, the results of this study appeared to reflect real world data at the moment. Despite these limitations, the present study clarifies that combined evaluation with the clinical T descriptor and CT features reasonably and properly reflects the recurrence rate. Conclusions In conclusion, a combined evaluation of CT features and T descriptor according to TNM 8th edition is useful for deciding on the surgical procedure for clinical 0 and IA adenocarcinoma from the perspective of recurrence. Pure GGO and cT1mi cases should be actively considered for sublobar resection, while cT1b (especially solid cT1b cases) and cT1c cases should be considered lobectomy to prevent recurrence. Abbreviations CT computed tomography TNM tumor node metastasis classification GGO ground glass opacity NSCLC non-small cell lung cancer CTR consolidation tumor ratio MRI magnetic resonance imaging FDG-PET fluorodeoxyglucose-positron emission tomography OS overall survival DFS disease-free survival CALBG Cancer and Leukemia Group B JCOG Japan Clinical Oncology Group Declarations Ethics approval and consent to participate Written informed consent was obtained from each patient to use their medical records. This study was approved by the institutional review of board of Kyushu University Hospital (IRB number: 2019-232). Consent for publication Not applicable Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests Funding No funding was received for this work. Authors’ contributions (I) Conception and design: Dr. T. Takenaka (II) Administrative support Drs. T. Tagawa, and M. Mori (III) Provision of study materials or patients: Drs. T Takenaka and T Tagawa, N Haratake, F Kinoshita (IV) Collection and assembly of data: Drs. T Takenaka, Y Ono, S Wakasu, Y Oku and F Kinoshita (V) Data analysis and interpretation: Dr. T. Takenaka (VI) Manuscript writing: Dr. T. Takenaka All authors read and approved final manuscript. Acknowledgement We thank Japan Medical Communications (https://www.japan-mc.co.jp/) for editing drafts of this manuscript. References Global Burden of Disease Cancer Collaboration; Fitzmaurice C, Akinyemiju TF, Al Lami FH, Alam T, Alizadeh-Navaei R, Allen C, et al. Global, Regional, and National Cancer Incidence, Mortality, Years of Life Lost, Years Lived With Disability, and Disability-Adjusted Life-Years for 29 Cancer Groups, 1990 to 2016: A Systematic Analysis for the Global Burden of Disease Study. JAMA Oncol. 2018;4:1553-1568. 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Kinoshita F, Toyokawa G, Matsubara T, Kozuma Y, Haratake N, Takamori S, et al. Prognosis of Early-stage Part-solid and Pure-solid Lung. Anticancer Res. 2019;39:2665-2670. Ginsberg RJ, Rubinstein LV. Randomized trial of lobectomy versus limited resection for T1 N0 non-small cell lung cancer. Lung Cancer Study Group. Ann Thorac Surg. 1995;60:615–22. Zhang Y, Sun Y, Wang R, Ye T, Zhang Y, Chen H. Meta-analysis of lobectomy, segmentectomy, and wedge resection for stage I non-small cell lung cancer. J Surg Oncol. 2015;111:334-40. Okami J, Shintani Y, Okumura M, Ito H, Ohtsuka T, Toyooka S, et al; Japanese Joint Committee of Lung Cancer Registry. Demographics, Safety and Quality, and Prognostic Information in Both the Seventh and Eighth Editions of the TNM Classification in 18,973 Surgical Cases of the Japanese Joint Committee of Lung Cancer Registry Database in 2010. J Thorac Oncol. 2019;14:212-222. Nakamura K, Saji H, Nakajima R, Okada M, Asamura H, Shibata T, et al. A phase III randomized trial of lobectomy versus limited resection for small-sized peripheral non-small cell lung cancer (JCOG0802/WJOG4607L). Jpn J Clin Oncol. 2010;40:271-4. Kohman LJ, Gu L, Altorki N, Scalzetti E, Veit LJ, Wallen JM, et al. Biopsy first: lessons learned from cancer and leukemia Group B (CALGB) 140503. J Thorac Cardiovasc Surg. 2017;153:1592–7. Travis WD, Brambilla E, Noguchi M, Nicholson AG, Geisinger KR, Yatabe Y, et al. International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society international multidisciplinary classification of lung adenocarcinoma. J Thorac Oncol. 2011;6:244–285. Hattori A, Matsunaga T, Takamochi K, Oh S, Suzuki K. Locoregional recurrence after segmentectomy for clinical-T1aN0M0 radiologically solid non-small-cell lung carcinoma. Eur J Cardiothorac Surg. 2017;51:518-525. Takenaka T, Yamazaki K, Miura N, Takeo S. Prognostic ability of new T1 descriptors in the tumour, node and metastasis classification of surgically treated non-small-cell lung cancer Interact Cardiovasc Thorac Surg. 2018;27:714-719 Cite Share Download PDF Status: Published Journal Publication published 29 Jan, 2022 Read the published version in Anticancer Research → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-330128","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":16580785,"identity":"6f3e607f-538c-4977-bb0c-637bd1940340","order_by":0,"name":"Tomoyoshi 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University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yuki","middleName":"","lastName":"Ono","suffix":""},{"id":16580790,"identity":"98c9c69a-555b-40e6-9d97-b87ba5094774","order_by":5,"name":"Sho Wakasu","email":"","orcid":"","institution":"Kyushu University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Sho","middleName":"","lastName":"Wakasu","suffix":""},{"id":16580791,"identity":"5de1bb75-cf9e-4e33-8f52-181ac86f1f01","order_by":6,"name":"Yuka Oku","email":"","orcid":"","institution":"Kyushu University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yuka","middleName":"","lastName":"Oku","suffix":""},{"id":16580792,"identity":"58270142-254e-48a9-ab9e-5b23d762d77e","order_by":7,"name":"Masaki Mori","email":"","orcid":"","institution":"Kyushu University: Kyushu Daigaku","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Masaki","middleName":"","lastName":"Mori","suffix":""}],"badges":[],"createdAt":"2021-03-14 22:32:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-330128/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-330128/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.21873/anticanres.15577","type":"published","date":"2022-01-29T15:21:43+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":7171465,"identity":"324531d9-17e6-403d-934a-994a8544a6cd","added_by":"auto","created_at":"2021-03-19 22:47:57","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":122002,"visible":true,"origin":"","legend":"Kaplan–Meier curves for overall survival (A) and disease-free survival (B) of all cases according to the T descriptors of TNM 8th edition ","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-330128/v1/fb125733664acd4633b5b4dc.png"},{"id":17772173,"identity":"257be4cb-7278-4158-b157-35442d551144","added_by":"auto","created_at":"2022-01-29 15:21:46","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":444594,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-330128/v1/1a391703-f930-474a-9451-313fc5b4bf01.pdf"}],"financialInterests":"","formattedTitle":"Consideration of the Optimal Surgical Procedure Based on the Risk of Recurrence in Clinical Stage 0 or IA Lung Adenocarcinoma","fulltext":[{"header":"Background","content":"\u003cp\u003eThere were 2.0\u0026nbsp;million incident cases of lung cancer and 1.7\u0026nbsp;million deaths in 2016; lung cancer continues to be the most common type of cancer [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. However, widespread screening with low-dose helical computed tomography (CT) has led to an improved rate of early detection for small-sized lung cancers [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSince the 1970s, tumor size has been a primary descriptor, and a significant prognostic factor for lung cancer in the tumor, node, metastasis (TNM) classification of the staging system of the Union for International Cancer Control [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. In the 8th edition of the TNM classification for non-small cell lung cancer (NSCLC), the cT category is defined by the tumor size, but only the size of the solid component on CT for prognostic stratification [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Recently, several researchers have reported that radiologically determined pure-solid lung cancers without a ground glass opacity (GGO) component exhibit more malignant behavior than the tumors with GGO [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Thus, whether or not patients with solid tumors should be treated similarly to patients with part-solid tumors with equal-sized solid components is controversial.\u003c/p\u003e\u003cp\u003eAlthough lobectomy is the standard resection approach for patients with clinical stage I NSCLC who can tolerate lobectomy, according to a previous randomized controlled trial comparing lobectomy with sublobar resection including segmentectomy and wide-wedge resection [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], sublobar resection is widely performed for early-stage NSCLC due to its improved diagnostic ability for cases with a good prognosis [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. According to The Japanese Joint Committee of Lung Cancer Registry reports, 22.7% of cases of lung cancer resection cases received sublobar resection in 2010 [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In addition, a phase III study was conducted to evaluate the non-inferiority of segmentectomy compared with lobectomy in patients with small peripheral NSCLC (\u0026le;\u0026thinsp;2cm diameter) in Japan and in the United States [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. However, what kind of patients should be actively indicated for sublobar resection has not yet been established.\u003c/p\u003e\u003cp\u003eIn the present study, we assessed the CT features and optimal surgical procedures for clinical stage 0 or IA adenocarcinoma according to the current staging system from the perspective of recurrence.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec2\" class=\"Section2\"\u003e \u003cdiv id=\"Sec3\" class=\"Section3\"\u003e\u003ch2\u003ePatients\u003c/h2\u003e\u003cp\u003eWe included 508 consecutive patients who were diagnosed with clinical stage 0 or IA NSCLC according to the TNM 8th edition, and underwent surgery between January 2009 and December 2018 at our department.\u003c/p\u003e\u003cp\u003e Written informed consent was obtained from each patient to use their medical records. This study was approved by the institutional review of board of Kyushu University Hospital (IRB number: 2019\u0026thinsp;\u0026minus;\u0026thinsp;232).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section3\"\u003e\u003ch2\u003eThe perioperative examination\u003c/h2\u003e\u003cp\u003eContrast-enhanced CT was routinely performed during each preoperative examination of the entire lung except for contraindicated cases. Images were viewed on standard lung windows (level: \u0026minus;500 to \u0026minus;\u0026thinsp;700 HU; width: 1500 to 2000 HU). The whole tumor size and solid component size were determined from the maximum diameter of the tumors and the solid part of the tumors, respectively. Tumors were divided into pure GGO, part-solid tumors and solid tumors based on the consolidation tumor ratio (CTR) in thin-section CT: pure GGO, CTR\u0026thinsp;=\u0026thinsp;0; part-solid, 0\u0026thinsp;\u0026lt;\u0026thinsp;CTR\u0026thinsp;\u0026lt;\u0026thinsp;1; solid, CTR\u0026thinsp;=\u0026thinsp;1. Clinical staging was determined based on the findings of chest and upper abdomen CT, brain CT or magnetic resonance imaging (MRI), radionuclide bone scans and/or with fluorodeoxyglucose-positron emission tomography (FDG-PET). Endobronchial ultrasound mediastinal lymph node biopsies were performed when nodal involvement was suspected. The histologic types of the lung adenocarcinoma were classified according to the International Association for the Study of Lung Cancer /American Thoracic Society/European Society of Thoracic Surgeons classification [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eFollow-up examinations were usually conducted every three to four months for the first two years and every three to six months thereafter. Routine follow-up procedures included a physical examination, hematological examination and chest radiography. In addition, chest and abdominal CT were performed at least once a year. If recurrent disease was suspected, further evaluations, such as MRI and FDG-PET were added. Recurrent NSCLC was diagnosed based on physical examinations and diagnostic imaging findings consistent with recurrent disease. When clinically feasible, diagnoses were histologically confirmed.\u003c/p\u003e\u003cp\u003eThe date of recurrence was defined when recurrence was histologically proven or, in cases that were diagnosed by clinical evidence, when recurrent disease was recognized by the attending physician.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section3\"\u003e\u003ch2\u003eOperation Policy\u003c/h2\u003e\u003cp\u003eWith regard to the agreement at our institution, if a tumor was pure GGO or GGO-dominant, the patients actively received sublobar resection, whereas major lung dissection with systematic or selective lymph node dissection was warranted for part-solid or solid tumors. Some patients who were elderly, had a high cardiopulmonary risk or could not tolerate lobectomy for any other reason reluctantly received sublobar resection.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\u003ch2\u003eData collection and extraction\u003c/h2\u003e\u003cp\u003eDemographic, clinical and treatment data were extracted from an institutional database that included all patients who had undergone thoracic surgery. For cases before 2017, clinical T staging was reassigned in accordance with the 8th edition of the TNM classification.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\u003ch2\u003eStatistical analyses\u003c/h2\u003e\u003cp\u003eComparisons of continuous and dichotomous variables between groups were performed with Student\u0026rsquo;s \u003cem\u003et\u003c/em\u003e-test and the \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e-test, respectively. The probability of a survival was estimated by the Kaplan\u0026ndash;Meier method. Differences in the survival were evaluated by log-rank tests. The analyses were performed using the JMP software package (version 11, SAS Institute Inc., Cary, North Carolina). \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered significant.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Results","content":" \u003cp\u003eThe characteristics of the 508 patients are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Preoperative chest CT showed 74 pure GGO cases, 237 part-solid tumors and 197 solid tumors. The types of procedures included lobectomy (n\u0026thinsp;=\u0026thinsp;328), segmentectomy (n\u0026thinsp;=\u0026thinsp;73) and wedge resection (n\u0026thinsp;=\u0026thinsp;107). The median duration of follow-up after surgical resection was 49 months (range: 1\u0026ndash;121 months). The mean tumor measurements were a whole tumor size of 18 mm (range: 5 \u0026minus;\u0026thinsp;30 mm) and solid component size of 12 mm (0\u0026ndash;30 mm) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The clinical T descriptor according to the TNM 8th edition was cTis in 74 patients (15%), cT1mi in 68 patients (13%), cT1a in 94 patients (19%), cT1b in 181 patients (36%), and cT1c in 91 patients (18%) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePatients\u0026rsquo; characteristics\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;508\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (range) (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e67 (33 to 88)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e239 (47%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e269 (53%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCT features\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePure GGO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e74 (15%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePart-solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e237 (47%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e197 (39%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWhole tumor size (mean)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5\u0026ndash;30 mm (18 mm)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid component size (mean)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026ndash;30 mm (12 mm)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecT descriptor according to TNM 8th edition\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e74 (15%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1mi\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e68 (13%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e94 (19%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e181 (36%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e91 (18%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgical procedure\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLobectomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e328 (65%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSegmentectomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e73 (14%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWedge resection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e107 (21%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epTNM stage 8th edition\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e35 (7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage IA1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e142 (28%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage IA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e185 (36%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage IA3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e51 (10%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage IB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50 (10%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage II\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20 (4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage III\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21 (4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage IVa\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eCT, computed tomography; GGO, ground glass opacity; TNM, tumor node metastases\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eFor the entire cohort, the 5-year overall survival (OS) rate was 93.8%, and the 5-year disease-free survival (DFS) rate was 87.5%. Kaplan-Meier analyses of the OS and DFS according to the clinical T descriptors on the 8th edition of the TNM classification are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB. The respective 5-year OS and DFS rates by clinical descriptors were as follows: 97.6% and 97.6% in cTis, 95.4% and 95.4% in cT1mi, 96.4% and 93.9% in cT1a, 92.4% and 84.8% in cT1b and 89.2% and 70.8% in cT1c (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB). The correlation between the surgical procedure and CT features or clinical T descriptors is shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The patients with solid tumors or a large number of T descriptors received lobectomy more often than others (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001 and p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eRelationship between CT features, clinical T factor and surgical procedure\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLobectomy\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSublobar resection\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;328)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;180)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCT features\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePure GGO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29 (39.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45 (60.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePart-solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e143 (60.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95 (39.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e156 (79.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40 (20.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecT descriptor according to TNM 8th edition\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29 (39.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45 (60.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1mi\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31 (45.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37 (54.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52 (55.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42 (44.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e139 (76.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42 (23.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e77 (84.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (15.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eCT, computed tomography; GGO, ground glass opacity; TNM, tumor node metastases\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eRecurrence was observed in 46 cases (9%) including 11 patients with part-solid tumors (4.6%) and 35 patients with solid tumors (17.9%) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Recurrence occurred in 3 patients (3.1%) with cT1a, 23 patients (12.7%) with cT1b and 20 patients (22.0%) with cT1c. No recurrence was observed in pure GGO, cTis or cT1mi cases (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The presence or absence of recurrence and CT features or surgical procedure in cT1a, T1b and cT1c cases is shown in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. For cT1a cases, the CT features and surgical procedure did not influence the recurrence rate; however, for cT1b cases, solid cases developed recurrence significantly more often than part-solid cases (p\u0026thinsp;=\u0026thinsp;0.046). Although it was not statistically significant, patients who received sublobar resection developed recurrence more often than the patients who receive lobectomy (p\u0026thinsp;=\u0026thinsp;0.053). For cT1c cases, there were no significant difference in the recurrence rate between part-solid cases and solid cases; however, the patients who received sublobar resection developed recurrence more often recurrence than the patients who received lobectomy (p\u0026thinsp;=\u0026thinsp;0.023).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eRecurrence rate according to CT features and clinical T factor\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRecurrence\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNot recurrence\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;46)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;462)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCT features\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePure GGO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45 (60.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePart-solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11 (4.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95 (39.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e35 (17.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40 (20.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecT descriptor according to TNM 8th edition\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e74 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1mi\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (3.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e91 (96.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23 (12.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e158 (87.3 %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20 (22.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e71 (78.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eCT, computed tomography; GGO, ground glass opacity; TNM, tumor node metastases\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eRecurrence rate according to tumor morphology and surgical procedures in cT1a, T1b and T1c cases.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecT1a cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRecurrence\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNot recurrence\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;91)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCT features\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePart-solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (2.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79 (97.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;=\u0026thinsp;0.320\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12 (92.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgical procedure\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003elobectomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (5.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e49 (94.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;=\u0026thinsp;0.114\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSublobar resection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ecT1b cases\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRecurrence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRecurrence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;158)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCT features\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePart-solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (6.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e69 (93.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;=\u0026thinsp;0.046\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18 (16.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e89 (83.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgical procedure\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003elobectomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (10.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e125 (89.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;=\u0026thinsp;0.053\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSublobar resection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (21.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33 (78.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ecT1c cases\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRecurrence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNot recurrence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;71)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCT features\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePart-solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (25.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12 (75.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;=\u0026thinsp;0.748\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16 (21.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e59 (78.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgical procedure\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003elobectomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (18.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e64 (82.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u0026thinsp;=\u0026thinsp;0.023\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSublobar resection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (46.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7 (53.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eCT, computed tomography\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e "},{"header":"Discussion","content":"\u003cp\u003eAccording to the 8th edition of the TNM classification for NSCLC, the T classifications of the tumors\u0026thinsp;\u0026le;\u0026thinsp;3 in diameters are based only on the size of the solid component on CT or the size of the invasive component at the pathologic examination, as the size of the solid/invasive component is considered to determine the prognosis [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. In the present study, we first compared OS and DFS of all cases according to the clinical T factor of the TNM 8th edition in clinical stage 0 or IA lung adenocarcinoma. These results indicated that the prognosis of all cases was well stratified according to the classification in this study. However, on comparing the DFS values for cT1mi and cT1c, the 5-year DFS rate was about 25% different, despite being the same clinical IA stage; therefore, the current treatment strategy, such as the timing of treatment and surgical procedure should be considered carefully. In addition, although this stratification using the classification is useful with regard to the prognosis as well, several issues must be addressed due to switching from the conventional evaluation method involving the maximum tumor diameter. One problems is that the suitability of current treatment strategies, such as limited resection, adjuvant therapy and follow-up, is considered based on the previous staging system.\u003c/p\u003e\u003cp\u003eAlthough lobectomy is the standard procedure for managing early stage NSCLC [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], sublobar resection, such as segmentectomy and wedge resection, are widely performed for small NSCLC in clinical practice [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Thus, randomized phase III studies such as Cancer and Leukemia Group B (CALBG) 140503 and Japan Clinical Oncology Group (JCOG) 0802 were conducted in United States and Japan to evaluate the non-inferiority of segmentectomy compared with lobectomy in patients with small peripheral NSCLC. The CALBG and JCOG studies targeted NSCLC patients with a whole tumor size of \u0026le;\u0026thinsp;2cm [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Therefore, the whole tumor size, including ground-glass and lepidic components on radiology and pathology is required in order to evaluate separately from new TNM classification.\u003c/p\u003e\u003cp\u003eIt is also necessary to consider surgical procedures according to the current staging system; therefore, we evaluated the optimal surgical procedures for clinical stage 0and IA adenocarcinoma according to the CT features and current T descriptors in this study. Our results showed no recurrence in cTis and cT1mi cases, regardless of surgical procedure; therefore, we may actively consider performing sublobar resection for cTis and cT1mi cases. In addition, regarding cT1a cases, only 3% of all such cases experienced recurrence (all 3 recurrent cases received lobectomy); therefore, the indication of those cases for sublobar resection is appropriate. Regarding cT1b and cT1c cases, patients who received sublobar resection experienced recurrence more often than others. Although the recurrence rate of solid tumors was significantly higher than that of part-solid tumors among cT1b cases, no significant difference was observed between part-solid and solid tumors among cT1a and cT1c cases.\u003c/p\u003e\u003cp\u003eSeveral studies have recently indicated that tumors with GGO components have a better prognosis than those without GGO component [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Fu et al. reported that the presence of GGO components was a strong predictor in patients with invasive pathological stage I NSCLC [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Hattori et al. also reported that the presence of GGO component had a marked impact on the favorable prognosis of small lung adenocarcinoma [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. They found that solid tumors with clinical stageIA1, IA2 and IA3 had a significantly worse prognosis than the part-solid tumors of the same clinical stage [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Hattori et al. also reported that segmentectomy and a larger tumor size were independent significant clinical factors of loco-regional recurrence in clinical T1aN0M0 (TNM 7th staging) solid NSCLC [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. There has also been a report comparing the prognosis of solid and part-solid tumors subjected to lobectomy. Takenaka et al. reported a study comparing part-solid and solid tumors among clinical stage IA NSCLC patients who received lobectomy [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Although the patients with solid tumors had a significantly worse outcome than those with part-solid tumors in all cases, the propensity-matched analysis detected no significant difference in the survival between the patients with solid and part-solid tumors when matched according to the size of the solid component [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. These present and previous findings suggest that, for now, the indications for sublobar resection for solid tumors should be carefully determined, even in cases of small adenocarcinoma.\u003c/p\u003e\u003cp\u003eSeveral limitations associated with the present study warrant mention. First, this study had a retrospective observational design and used a single-institution Japanese database to enroll only patients who had undergone surgical resections. Second, the surgical procedures were selected according to the individual patients and were not randomized. Although the results of Phase III trials are required to establish evidence supporting limited resection for early stage NSCLC, the results of this study appeared to reflect real world data at the moment. Despite these limitations, the present study clarifies that combined evaluation with the clinical T descriptor and CT features reasonably and properly reflects the recurrence rate.\u003c/p\u003e"},{"header":"Conclusions","content":" \u003cp\u003eIn conclusion, a combined evaluation of CT features and T descriptor according to TNM 8th edition is useful for deciding on the surgical procedure for clinical 0 and IA adenocarcinoma from the perspective of recurrence. Pure GGO and cT1mi cases should be actively considered for sublobar resection, while cT1b (especially solid cT1b cases) and cT1c cases should be considered lobectomy to prevent recurrence.\u003c/p\u003e "},{"header":"Abbreviations","content":" \u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecomputed tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTNM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003etumor node metastasis classification\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGGO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eground glass opacity\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eNSCLC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003enon-small cell lung cancer\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCTR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003econsolidation tumor ratio\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMRI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003emagnetic resonance imaging\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFDG-PET\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003efluorodeoxyglucose-positron emission tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eoverall survival\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDFS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003edisease-free survival\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCALBG\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCancer and Leukemia Group B\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eJCOG\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eJapan Clinical Oncology Group\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e "},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from each patient to use their medical records. This study was approved by the institutional review of board of Kyushu University Hospital (IRB number: 2019-232).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was received for this work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(I) Conception and design: Dr. T. Takenaka\u003c/p\u003e\n\u003cp\u003e(II) Administrative support Drs. T. Tagawa, and M. Mori\u003c/p\u003e\n\u003cp\u003e(III) Provision of study materials or patients: Drs. T Takenaka and T Tagawa, N Haratake, F Kinoshita\u003c/p\u003e\n\u003cp\u003e(IV) Collection and assembly of data: Drs. T Takenaka, Y Ono, S Wakasu, Y Oku and F Kinoshita\u003c/p\u003e\n\u003cp\u003e(V) Data analysis and interpretation: Dr. T. Takenaka\u003c/p\u003e\n\u003cp\u003e(VI) Manuscript writing: Dr. T. Takenaka\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;All authors read and approved final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank Japan Medical Communications (https://www.japan-mc.co.jp/) for editing drafts of this manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eGlobal Burden of Disease Cancer Collaboration; Fitzmaurice C, Akinyemiju TF, Al Lami FH, Alam T, Alizadeh-Navaei R, Allen C, et al. Global, Regional, and National Cancer Incidence, Mortality, Years of Life Lost, Years Lived With Disability, and Disability-Adjusted Life-Years for 29 Cancer Groups, 1990 to 2016: A Systematic Analysis for the Global Burden of Disease Study. JAMA Oncol. 2018;4:1553-1568.\u003c/li\u003e\n\u003cli\u003eAberle DR,\u0026nbsp;DeMello S,\u0026nbsp;Berg CD,\u0026nbsp;Black WC,\u0026nbsp;Brewer B,\u0026nbsp;Church TR, et al. Results of the two incidence screenings in the National Lung Screening Trial. N Engl J Med. 2013;369:920-31.\u003c/li\u003e\n\u003cli\u003eMountain CF. Revisions in the International System for Staging Lung Cancer. Chest . 1997;111:1710\u0026ndash;1717.\u003c/li\u003e\n\u003cli\u003eRami-Porta R, Asamura H, Travis WD, Rusch VW. Lung cancer-major changes in the American Joint Committee on Cancer eighth edition cancer staging manual. CA Cancer J Clin. 2017;67:138-155.\u003c/li\u003e\n\u003cli\u003eHattori A, Hirayama S, Matsunaga T, Hayashi T, Takamochi K, Oh S, et al. Distinct Clinicopathologic Characteristics and Prognosis Based on the Presence of Ground Glass Opacity Component in Clinical Stage IA Lung Adenocarcinoma. J Thorac Oncol. 2019;14:265-275.\u003c/li\u003e\n\u003cli\u003eFu F, Zhang Y, Wen Z, Zheng D, Gao Z, Han H, et al. Distinct Prognostic Factors in Patients with Stage I Non\u0026ndash;Small Cell Lung Cancer with Radiologic Part-Solid or Solid Lesions. J Thorac Oncol. 2019;14:2133-2142.\u003c/li\u003e\n\u003cli\u003eKinoshita F, Toyokawa G, Matsubara T, Kozuma Y, Haratake N, Takamori S, et al. Prognosis of Early-stage Part-solid and Pure-solid Lung. Anticancer Res. 2019;39:2665-2670.\u003c/li\u003e\n\u003cli\u003eGinsberg RJ, Rubinstein LV. Randomized trial of lobectomy versus limited resection for T1 N0 non-small cell lung cancer. Lung Cancer Study Group. Ann Thorac Surg. 1995;60:615\u0026ndash;22.\u003c/li\u003e\n\u003cli\u003eZhang Y, Sun Y, Wang R, Ye T, Zhang Y, Chen H. Meta-analysis of lobectomy, segmentectomy, and wedge resection for stage I non-small cell lung cancer. J Surg Oncol. 2015;111:334-40.\u003c/li\u003e\n\u003cli\u003eOkami J, Shintani Y, Okumura M, Ito H, Ohtsuka T, Toyooka S, et al; Japanese Joint Committee of Lung Cancer Registry. Demographics, Safety and Quality, and Prognostic Information in Both the Seventh and Eighth Editions of the TNM Classification in 18,973 Surgical Cases of the Japanese Joint Committee of Lung Cancer Registry Database in 2010. J Thorac Oncol. 2019;14:212-222.\u003c/li\u003e\n\u003cli\u003eNakamura K, Saji H, Nakajima R, Okada M, Asamura H, Shibata T, et al. A phase III randomized trial of lobectomy versus limited resection for small-sized peripheral non-small cell lung cancer (JCOG0802/WJOG4607L). Jpn J Clin Oncol. 2010;40:271-4.\u003c/li\u003e\n\u003cli\u003eKohman LJ, Gu L, Altorki N, Scalzetti E, Veit LJ, Wallen JM, et al. Biopsy first: lessons learned from cancer and leukemia Group B (CALGB) 140503. J Thorac Cardiovasc Surg. 2017;153:1592\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003eTravis WD, Brambilla E, Noguchi M, Nicholson AG, Geisinger KR, Yatabe Y, et al. International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society international multidisciplinary classification of lung adenocarcinoma. J Thorac Oncol. 2011;6:244\u0026ndash;285.\u003c/li\u003e\n\u003cli\u003eHattori A, Matsunaga T, Takamochi K, Oh S, Suzuki K. Locoregional recurrence after segmentectomy for clinical-T1aN0M0 radiologically solid non-small-cell lung carcinoma. Eur J Cardiothorac Surg. 2017;51:518-525.\u003c/li\u003e\n\u003cli\u003eTakenaka T, Yamazaki K, Miura N, Takeo S. Prognostic ability of new T1 descriptors in the tumour, node and metastasis classification of surgically treated non-small-cell lung cancer Interact Cardiovasc Thorac Surg. 2018;27:714-719\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"lung adenocarcinoma, TNM staging, surgical resection, recurrence","lastPublishedDoi":"10.21203/rs.3.rs-330128/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-330128/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003e Although sublobar resection is widely performed for early-stage non-small cell lung cancer, what kind of patients should be actively indicated for sublobar resection has not yet been established according to 8th edition of tumor node metastasis classification (TNM). We evaluated the computed tomography (CT) features and optimal surgical procedures of clinical stage 0 or IA adenocarcinoma from the perspective of recurrence.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eWe retrospectively investigated 508 lung adenocarcinoma diagnosed as c-stage 0 or IA in the 8th edition of TNM classification. A survival analysis was performed according to the clinical T descriptor, CT features and surgical procedures.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eThe tumors were classified as follows: 74 with pure ground glass opacity (GGO), 237 part-solid tumors and 197 solid tumors. The types of surgical procedures were lobectomy (n\u0026thinsp;=\u0026thinsp;328), segmentectomy (n\u0026thinsp;=\u0026thinsp;73) and wedge resection (n\u0026thinsp;=\u0026thinsp;107). Clinical T descriptors were cTis in 74 patients, cT1mi in 68 patients, cT1a in 94 patients, cT1b in 181 patients and cT1c in 91 patients. Recurrence was observed 46 cases (9%), including 3 (3.1%) with cT1a, 23 (12.7%) with cT1b and 20 (22.0%) with cT1c. No recurrence was observed in cTis or cT1mi cases. Solid tumors with cT1b recurred more often than part-solid tumors among cT1b cases (6.8% vs. 16.8%) (p\u0026thinsp;=\u0026thinsp;0.046). There were no marked differences in the recurrence rate between part-solid and solid tumors in the cT1a and cT1c groups. The patients who received sublobar resection developed recurrence more often than the patients who received lobectomy among cT1b cases (10.1% vs. 21.4%) and cT1c cases (18.0% vs. 46.2%) (p\u0026thinsp;=\u0026thinsp;0.053 and p\u0026thinsp;=\u0026thinsp;0.023).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003ePure GGO and cT1mi cases should be actively considered for sublobar resection, while cT1b (especially solid cT1b cases) and cT1c cases should be considered for lobectomy to prevent recurrence.\u003c/p\u003e","manuscriptTitle":"Consideration of the Optimal Surgical Procedure Based on the Risk of Recurrence in Clinical Stage 0 or IA Lung Adenocarcinoma","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-03-19 22:47:55","doi":"10.21203/rs.3.rs-330128/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c93b222e-1da7-4430-811b-e20ad0b65441","owner":[],"postedDate":"March 19th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":3034593,"name":"Surgery"},{"id":3034594,"name":"General Surgery"}],"tags":[],"updatedAt":"2022-01-29T15:21:43+00:00","versionOfRecord":{"articleIdentity":"rs-330128","link":"https://doi.org/10.21873/anticanres.15577","journal":{"identity":"anticancer-research","isVorOnly":true,"title":"Anticancer Research"},"publishedOn":"2022-01-29 15:21:43","publishedOnDateReadable":"January 29th, 2022"},"versionCreatedAt":"2021-03-19 22:47:55","video":"","vorDoi":"10.21873/anticanres.15577","vorDoiUrl":"https://doi.org/10.21873/anticanres.15577","workflowStages":[]},"version":"v1","identity":"rs-330128","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-330128","identity":"rs-330128","version":["v1"]},"buildId":"WrCJVZZCHTDjtuVLN7oU0","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}