Incidental finding of gastric lesions during endoscopic ultrasonography

Incidental finding of gastric lesions during endoscopic ultrasonography | 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 Incidental finding of gastric lesions during endoscopic ultrasonography Yusuke Okujima, Teru Kumagi, Mitsuhito Koizumi, Taira Kuroda, and 13 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3855715/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Gastric lesions may be incidentally detected during endoscopic ultrasonography (EUS). We aimed to clarify the detection rate of gastric lesions and the impact of awareness on the detection of gastric lesions during EUS. Methods This retrospective study collected data on age, sex, primary pancreatobiliary disease, indication for EUS and detection of gastric lesions. The detection rate of incidental gastric lesions and documentation of gastric findings was compared between patients who underwent EUS (1,932 procedures, 1,220 patients). A quick gastric screening during EUS was introduced in 2015; therefore, EUS was classified into the former group (2009–2014: 505 procedures, 409 patients) and the latter group (2015–2020: 1,427 procedures, 918 patients). Results Thirteen gastric lesions were incidentally detected during EUS, all in the latter group, including gastric cancer (n = 1), malignant lymphoma (n = 1), gastric adenoma (n = 1), gastric submucosal tumor (n = 2), and gastric ulcer (n = 8). The detection rate of gastric lesions was significantly higher in the latter group than in the former group per procedure (0.91% vs. 0%, P = 0.027) and per patient (1.41% vs. 0%, P = 0.015), and gastric findings were significantly more commonly described in patients’ medical records (39.8% vs. 2.97%, P < 0.001). Conclusions Gastric lesions may be encountered during EUS. A quick screening during EUS improved the detection rate of gastric lesions, presumably due to increased awareness of gastric lesions during the procedure. endoscopic ultrasonography gastric screening incidental finding gastric lesions Figures Figure 1 Figure 2 Figure 3 Introduction Endoscopic ultrasonography (EUS) is useful diagnostic and therapeutic procedures for patients with pancreatobiliary diseases [ 1 – 6 ]. An anterior oblique viewing endoscope is usually used for this procedure [ 7 ]. Oblique-viewing endoscope has a narrower field of view, poorer image quality, poor operability, and a limited range of angles compared with forward-viewing endoscopes [ 6 , 7 ]. Therefore, oblique-viewing endoscopes may miss upper gastrointestinal tract lesions [ 7 ]. In general, the endoscopists wish to begin ultrasound observation of the pancreatobiliary lesion sooner, which is the main objective, rather than observation of the stomach. For these reasons, screening of the upper gastrointestinal tract is not routinely performed during EUS. Certainly, no medical textbook on EUS refers to gastric lesions. Although eradication of Helicobacter pylori has decreased the risk of gastric cancer [ 8 ], it is still a major concern and the third leading cause of cancer death in Japan. Therefore, gastric cancer represents a nationwide medical burden and early detection is essential [ 8 ]. Endoscopic screening has been confirmed to be effective in reducing gastric cancer mortality [ 9 , 10 ]. The detection rate of gastric cancer through endoscopic screening is 0.43–0.87% in the general population in Japan [ 11 ]. However, the incidental detection rate of gastric lesions, especially gastric malignancies, during EUS is not fully understood. Incidental findings are common during routine investigations for other indications; for example, lung nodules or adrenal tumors are often detected on abdominal computed tomography scans performed to investigate abdominal pain. In a previous study, pancreatic ductal dilatation was detected on abdominal imaging during surveillance for hepatocellular carcinoma, leading to an early diagnosis of pancreatic cancer [ 12 ]. Therefore, clinician awareness of upper gastrointestinal tract lesions during EUS may play a role in the early diagnosis of gastric cancer. In this study, we aimed to evaluate the detection rate of gastric lesions and the impact of awareness on the observation of gastric lesions during EUS. Methods In this retrospective study, we examined data of consecutive patients who underwent EUS at Ehime University Hospital between January 2009 and December 2020. In this study, the endoscopic database system (Solemio, Olympus, Tokyo) was used to collect data on age, sex, purpose, primary disease, and gastric lesions described in the EUS report. Furthermore, if the gastric lesions described in the EUS report were "gastric cancer," "malignant lymphoma," "gastric submucosal tumor," "gastric adenoma," or "gastric ulcer," the pathological diagnosis was confirmed referring to the electronic medical record. We also confirmed whether these lesions were indeed newly detected lesions on EUS. For example, if a gastric lesion had been recognized by prior forward-viewing endoscope, it was excluded. Board-certified endoscopists performed or supervised all the procedures using the following endscopy: EG-3670URK, EG-3870UTK (Pentax, Tokyo), GF-UCT260, GF-UE260-AL5, GF-UE290 (Olympus, Tokyo). In our institution, we have recommended the screening of gastric lesions during EUS since 2015. Therefore, we divided patients who underwent EUS into a former group (2009–2014) and a latter group (2015–2020). This screening is performed with an endoscope for EUS. The stomach is insufflated and observed for gastric lesions within the visible area. The sequence of observations is up to the endoscopist, but the screening should be completed within three minutes at the most. We have also started to document gastric findings in EUS report as much as possible. Thus, gastric awareness during EUS was defined as description rate of gastric findings. The presence or absence of description on gastric findings were compared. Even if the report stated "no abnormality" in the stomach, it was included in the presence of description. The data are reported as mean ± standard deviation or number and percentage. Intergroup comparisons were performed using the chi-square test. Differences were considered statistically significant at two-tailed P values < 0.05. All statistical analyses were performed using the JMP software (version 13; SAS Institute, Cary, NC, USA). Data were stored in a secure database, and patients were numerically coded for anonymity. The study protocol conformed to the ethical guidelines of the Declaration of Helsinki and was approved by the ethics committee of the Ehime University Graduate School of Medicine (#1705002, #1903007). The requirement for informed consent was waived due to the retrospective nature of the study, but the option to withdraw from the study was provided. Results Patient background During the study period, 1,324 patients underwent 2,168 EUS. Analysis was carried out after 104 patients with 236 endoscopic procedures were excluded according to the exclusion criteria (Fig. 1 ). Patients who underwent EUS were divided into the former group (505 procedures, 409 patients) and the latter group (1,427 procedures, 918 patients). Patients who underwent EUS in both former and latter periods (107 patients) were assigned to both groups. The median age of patients in the latter EUS group was older than the former EUS group (66.4 ± 11.9 vs. 68.9 ± 10.7; P < 0.01) (Table 1 ). There was no difference in sex distribution between the two groups: 49.9% and 53.4% of patients were male in the former group and the latter group, respectively (P = 0.17). Table 1 Background of the patients underwent EUS (N = 1,932) The former EUS group (2009–2014, N = 505) The latter EUS group (2015–2020, N = 1,427) P-value Age 66.4 ± 11.9 68.9 ± 10.7 < 0.001 Sex (male) 252 (49.9%) 762 (53.4%) 0.178 Primary disease Pancreatic cyst Pancreatic cancer Bile duct cancer Bile duct stone Other disease 198 (39.2%) 96 (19.0%) 30 (5.9%) 30 (5.9%) 151 (29.9%) 666 (46.6%) 227 (15.9%) 64 (4.4%) 34 (2.3%) 436 (30.5%) 0.004 0.110 0.187 < 0.001 Description of gastric finding 15 (2.97%) 568 (39.8%) < 0.001 Incidental gastric finding Cancer Malignant lymphoma Adenoma Submucosal tumor Ulcer 0 0 0 0 0 1 1 1 2 8 0.027 Indications for EUS and type of endoscopes The indications for EUS were as follows: pancreatic cystic tumor (39.2%), pancreatic cancer (19.0%), bile duct cancer (5.9%), and bile duct stones (5.9%) in the former EUS group; and pancreatic cystic tumor (46.6%), pancreatic cancer (15.9%), bile duct cancer (4.4%), and bile duct stones (2.3%) in the latter EUS group. The latter group had more patients with pancreatic cystic tumors (P = 0.004). The scopes used in the former group were EG-3670URK (N = 311, 61.5%), EG-3870UTK (N = 129, 25.5%) and others (N = 65, 12.8%), whereas GF-UCT260 (N = 1180, 82.6%), GF-UE260-AL5 (N = 192, 13.4%) and others (N = 55, 3.8%) were used in the latter group. Incidental finding of gastric lesions during EUS Thirteen gastric lesions were incidentally found. The locations of the gastric lesions were as follows: lesser curvature of the gastric body (N = 4) and the angular region (N = 3), greater curvature of the pyloric antral zone (N = 3), posterior wall of the gastric body (N = 1) and the angular region (N = 1), and pyloric ring (N = 1). Two cases were gastric malignancies; the first was a 73-year-old man who underwent EUS (GF-UCT260) for intraductal papillary mucinous neoplasms (IPMNs) and was found to have early gastric cancer of 10mm in size of the lesser curvature of the gastric body (Fig. 3 A). When this patient first underwent EUS, screening for gastric lesions had not yet been applied, and the lesions were detected on the next EUS when that was applied. The second was a 75-year-old man who underwent EUS (GF-UCT260) for jaundice of unknown origin and was found to have malignant lymphoma of the lesser curvature of the gastric body (Fig. 3 B). The remaining ten cases were benign lesions: gastric adenoma (n = 1), gastric submucosal tumor (n = 2), and gastric ulcer (n = 8). All incidental gastric lesions were in detected in the latter group. Therefore, the detection rate of gastric lesions was significantly higher in the latter group than in the former group per procedure (0.91% vs. 0%, P = 0.027) and per patient (1.41% vs. 0%, P = 0.015) (Table 1 ). The primary diseases of the 13 patients (mean age 65.9 years) in whom incidental gastric lesions were found, and their odds ratio (OR) and 95% confidential interval (CI) were as follows: pancreatic cystic tumors (N = 5, 38.5%) [IPMN (N = 3, 23.0%), 2 SCN (N = 2, 15.3%)]; OR = 1.182 (95% CI = 0.384–3.635, P = 0.769); pancreatic neuroendocrine neoplasms (p-NEN) (N = 2, 15.3%), OR = 46.4 (95% CI = 8.112–265.4, P < 0.0001); biliary duct cancer (N = 2, 15.3%), OR = 1.149 (95% CI = 0.252–5.228, P = 0.857); pancreatic cancer (N = 1, 7.6%), OR = 0.530 (95% CI = 0.069–4.103, P = 0.536); and other pancreatobiliary diseases (N = 3, 23.0%). Of the 13 cases of incidentally found gastric lesions, 11 were found on initial EUS. Of the remaining two cases, one was the case described above (Fig. 3 A) and the other was an active gastric ulcer that occurred in a patient who had undergone multiple EUS procedures. Description rate of gastric finding and incidental finding of gastric lesions Figure 2 shows the annual change in description rate of gastric findings in medical record. A description of gastric findings during EUS was more significantly commonly documented in the medical records of patients in the latter group (568 of 1,427 examinations, 39.8%) than the former group (15 of 505 examinations, 2.97%) (P < 0.001, Table 1 ). Discussion This study evaluated the detection rate of gastric lesions during EUS. We found that the detection rate was 0% in the former EUS group, 0.91% in the latter EUS group (1.41% of patients). Therefore, increased awareness of gastric lesions during EUS might have helped improve the detection rate of gastric lesions. The incidental detection rate of gastric neoplasms during EUS is not well understood. Sahakian et al. reported that 2 out of 204 patients (0.98%) had neoplastic lesions detected during routine EGD before EUS [ 13 ]. In the prospective study of 368 patients, Wilcox reported that no patients had gastric malignancies when screened by duodenoscopy at ERCP [ 14 ]. In the latter EUS group in this study, we checked for gastric lesions in the visible area, and 2 of 918 patients (0.21%) with 1,427 procedures (0.14%) were found to have gastric malignancies. Considering that the detection rate of gastric cancer using forward-viewing endoscopes in the general population in Japan is 0.43–0.87% [ 10 ], our detection rate was low, but it was not a negligible rate; therefore, any abnormal findings that are noted during investigations should be closely inspected and documented in the patients’ endoscopy reports. There have been no reports on whether the detection rate increases with the presence or absence of awareness of incidental gastric lesions. Therefore, the impact of awareness on the incidental detection of gastric lesions is not understood. In this study, the detection rate of gastric lesions could be increased by brief screening of the stomach. Some studies comparing EUS/ERCP and EGD showed that there was no difference in the rate of missed gastric lesions [ 14 , 15 ]. In contrast, Ashby et al. reported that ERCP or EUS followed by EGD resulted in an approximately 20% increase in the detection rate of gastric lesions [ 7 ]. Although there is no consensus on the difference in detection rates between oblique-viewing endoscopes and forward-viewing endoscopes, the blind area is greater in oblique-viewing endoscopes than in forward-viewing endoscopes. However, we found that performing a screening during EUS had a beneficial effect on the detection of incidental gastric lesions. Gastric screening requires insufflation. Empirically, CO 2 insufflation unlikely interfere with ultrasound observation if observed with degassing. As a result of recent advances in diagnostic imaging, the detection rate of pancreatic cysts such as IPMNs has increased and the opportunity for EUS has increased, and this was seen in the latter EUS group in this study. Gastric screening during EUS is especially important in IPMNs because some studies have shown an association between IPMNs and extrapancreatic malignancies [ 16 ]. Indeed, in this study, gastric cancer was also identified in an IPMN case. In addition, the OR of incidental detection rate on gastric lesion in p-NEN was significantly high. Therefore, gastric screening with attention to gastric lesion may be advisable when performing EUS for patients with p-NEN. This study has some limitations. First, our study population was elderly, and these results may not be generalizable to the population undergoing general health examinations. Second, because of the retrospective nature of the study, it is possible that patients who had undergone EGD prior to EUS may have been included. However, all 13 lesions noted in this study are new lesions, and we believe that this has an impact on the detection rate of gastric lesions. Third, since the ultrasound scopes used in the former and latter groups differed widely, it is necessary to consider whether there is an improvement in the lesion detection rate due to the improved observation of the scopes. The EG-3670URK, used in 61.5% of the former group, had a 140-degree field of view and a forward viewing. EG-3870UTK, used in 25.5% of the former group, had a 120-degree visual field angle and 45-degree anterior oblique viewing. In contrast, GF-UCT260, used in 82.6% of the latter group, had a 100-degree field of view and 55-degree anterior oblique viewing, and GF-UE260-AL5, used in 13.4% of the latter group, had a 100-degree field of view and 55-degree anterior oblique viewing. Although quantitative comparisons regarding image quality could not be determined, it is difficult to consider that the difference in the detection rate of gastric lesions is due to improved observation of the scopes, since the former group, which includes more straightforward views, is rather more beneficial in this optical observation. Fourth, the order of observation and the number of images taken are left to the endoscopists, and there are no rules. If rules were established, the detection rate might increase, but this would have the disadvantage of requiring more time. Nonetheless, quick gastric screening during EUS seems to be beneficial on detecting incidental gastric lesions. In conclusion, clinician awareness of detecting gastric lesions and the introduction of a quick screening during EUS improved the detection rate of gastric lesions. Further improvement in the description rate of gastric findings in medical records may even increase the detection rate of gastric lesions. Declarations Funding This work was supported in part by a grant from the Grant-in-Aid for Scientific Research (Japan Society for the Promotion of Science, KAKENHI 18K07469) provided to Dr Kumagi. Author Contribution Study concept and design: YO (Okujima), TK (Kumagi), MK (Koizumi), TK (Kuroda), YI, KO. Acquisition: YO (Okujima), TK (Kumagi), MK (Koizumi), TK (Kuroda), YO (Ohno), YI, KO, KM, MK (Kokubu), YN, HY, NA, TY, YY, ET, YI, YH. Analysis: YO (Okujima), TK (Kumagi). Interpretation of data: YO (Okujima), TK (Kumagi). Statistical analysis: YO (Okujima), TK (Kumagi). Drafting of manuscript: YO (Okujima), TK (Kumagi), MK (Koizumi), TK (Kuroda), YO (Ohno), YI, KO, KM, MK (Kokubu), YN, HY, NA, TY, YY, ET, YI, YH. Important intellectual content and study supervision: TK (Kumagi), YH. Acknowledgement We would like to thank Editage [ http://www.editage.com ] for editing and reviewing this manuscript for English language. References Maple JT, Ben-Menachem T, Anderson MA, et al. 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The clinical utility of evaluating the luminal upper gastrointestinal tract during linear endoscopic ultrasonography. J Clin Gastroenterol. 2016; 50(7): 538–544. Baiocchi GL, Molfino S, Frittoli B, et al. Increased risk of second malignancy in pancreatic intraductal papillary mucinous tumors: review of the literature. World J Gastroenterol. 2015; 21(23): 7313–7319. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted 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. 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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-3855715","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":266628428,"identity":"96a4ec77-20a6-4fc0-95fc-96e6435a9369","order_by":0,"name":"Yusuke Okujima","email":"","orcid":"","institution":"Ehime University Hospital Shitsukawa","correspondingAuthor":false,"prefix":"","firstName":"Yusuke","middleName":"","lastName":"Okujima","suffix":""},{"id":266628429,"identity":"fa2b111b-fc8f-4f45-a417-bd0269d338bd","order_by":1,"name":"Teru 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Shitsukawa","correspondingAuthor":false,"prefix":"","firstName":"Eiji","middleName":"","lastName":"Takeshita","suffix":""},{"id":266628443,"identity":"3560068e-4657-46f9-a8e4-55e2d86ee416","order_by":15,"name":"Yoshio Ikeda","email":"","orcid":"","institution":"Ehime University Hospital Shitsukawa","correspondingAuthor":false,"prefix":"","firstName":"Yoshio","middleName":"","lastName":"Ikeda","suffix":""},{"id":266628444,"identity":"6583639c-2d88-4bf1-9be0-e7c02b93a219","order_by":16,"name":"Yoichi Hiasa","email":"","orcid":"","institution":"Ehime University Hospital Shitsukawa","correspondingAuthor":false,"prefix":"","firstName":"Yoichi","middleName":"","lastName":"Hiasa","suffix":""}],"badges":[],"createdAt":"2024-01-12 04:59:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3855715/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3855715/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":49646805,"identity":"17e849b8-44c9-4a0c-a615-231bd3544d12","added_by":"auto","created_at":"2024-01-15 21:10:38","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":83265,"visible":true,"origin":"","legend":"\u003cp\u003eStudy flow chart.\u003c/p\u003e","description":"","filename":"Slide1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3855715/v1/353e2209363dac9744f3d9ba.jpg"},{"id":49646237,"identity":"3f7e3861-7caf-424b-8b66-4ba287ba3ee9","added_by":"auto","created_at":"2024-01-15 21:02:38","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":50636,"visible":true,"origin":"","legend":"\u003cp\u003eDescription rate of gastric findings into medical records.\u003c/p\u003e","description":"","filename":"Slide2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3855715/v1/527bf21af60e5121995ccb20.jpg"},{"id":49646239,"identity":"cfa121bc-3249-4855-8b9f-6aab2c42ed0d","added_by":"auto","created_at":"2024-01-15 21:02:38","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":87879,"visible":true,"origin":"","legend":"\u003cp\u003eIncidentally detected gastric malignancies.\u003c/p\u003e\n\u003cp\u003eA: A 73-year-old man underwent EUS (GF-UCT260) for IPMNs, and early gastric cancer of lesser curvature side of gastric body was detected.\u003c/p\u003e\n\u003cp\u003eB: A 75-year-old man underwent EUS (GF-UCT260) for jaundice of unknown origin, and malignant lymphoma of lesser curvature side of gastric body was detected. This image was taken with forward-viewing endoscope.\u003c/p\u003e","description":"","filename":"Slide3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3855715/v1/b141856012d5a4616d84f203.jpg"},{"id":49777373,"identity":"f65c14e0-a295-405d-bf4b-acc4f66a71e5","added_by":"auto","created_at":"2024-01-17 21:23:31","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":422047,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3855715/v1/920eaa3d-8281-484b-a149-6f98f43e28c2.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Incidental finding of gastric lesions during endoscopic ultrasonography","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEndoscopic ultrasonography (EUS) is useful diagnostic and therapeutic procedures for patients with pancreatobiliary diseases [\u003cspan additionalcitationids=\"CR2 CR3 CR4 CR5\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. An anterior oblique viewing endoscope is usually used for this procedure [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Oblique-viewing endoscope has a narrower field of view, poorer image quality, poor operability, and a limited range of angles compared with forward-viewing endoscopes [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Therefore, oblique-viewing endoscopes may miss upper gastrointestinal tract lesions [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. In general, the endoscopists wish to begin ultrasound observation of the pancreatobiliary lesion sooner, which is the main objective, rather than observation of the stomach. For these reasons, screening of the upper gastrointestinal tract is not routinely performed during EUS. Certainly, no medical textbook on EUS refers to gastric lesions.\u003c/p\u003e \u003cp\u003eAlthough eradication of \u003cem\u003eHelicobacter pylori\u003c/em\u003e has decreased the risk of gastric cancer [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], it is still a major concern and the third leading cause of cancer death in Japan. Therefore, gastric cancer represents a nationwide medical burden and early detection is essential [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Endoscopic screening has been confirmed to be effective in reducing gastric cancer mortality [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. The detection rate of gastric cancer through endoscopic screening is 0.43\u0026ndash;0.87% in the general population in Japan [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, the incidental detection rate of gastric lesions, especially gastric malignancies, during EUS is not fully understood.\u003c/p\u003e \u003cp\u003eIncidental findings are common during routine investigations for other indications; for example, lung nodules or adrenal tumors are often detected on abdominal computed tomography scans performed to investigate abdominal pain. In a previous study, pancreatic ductal dilatation was detected on abdominal imaging during surveillance for hepatocellular carcinoma, leading to an early diagnosis of pancreatic cancer [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Therefore, clinician awareness of upper gastrointestinal tract lesions during EUS may play a role in the early diagnosis of gastric cancer. In this study, we aimed to evaluate the detection rate of gastric lesions and the impact of awareness on the observation of gastric lesions during EUS.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eIn this retrospective study, we examined data of consecutive patients who underwent EUS at Ehime University Hospital between January 2009 and December 2020. In this study, the endoscopic database system (Solemio, Olympus, Tokyo) was used to collect data on age, sex, purpose, primary disease, and gastric lesions described in the EUS report. Furthermore, if the gastric lesions described in the EUS report were \"gastric cancer,\" \"malignant lymphoma,\" \"gastric submucosal tumor,\" \"gastric adenoma,\" or \"gastric ulcer,\" the pathological diagnosis was confirmed referring to the electronic medical record. We also confirmed whether these lesions were indeed newly detected lesions on EUS. For example, if a gastric lesion had been recognized by prior forward-viewing endoscope, it was excluded. Board-certified endoscopists performed or supervised all the procedures using the following endscopy: EG-3670URK, EG-3870UTK (Pentax, Tokyo), GF-UCT260, GF-UE260-AL5, GF-UE290 (Olympus, Tokyo). In our institution, we have recommended the screening of gastric lesions during EUS since 2015. Therefore, we divided patients who underwent EUS into a former group (2009\u0026ndash;2014) and a latter group (2015\u0026ndash;2020).\u003c/p\u003e \u003cp\u003eThis screening is performed with an endoscope for EUS. The stomach is insufflated and observed for gastric lesions within the visible area. The sequence of observations is up to the endoscopist, but the screening should be completed within three minutes at the most.\u003c/p\u003e \u003cp\u003eWe have also started to document gastric findings in EUS report as much as possible. Thus, gastric awareness during EUS was defined as description rate of gastric findings. The presence or absence of description on gastric findings were compared. Even if the report stated \"no abnormality\" in the stomach, it was included in the presence of description.\u003c/p\u003e \u003cp\u003eThe data are reported as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or number and percentage. Intergroup comparisons were performed using the chi-square test. Differences were considered statistically significant at two-tailed P values\u0026thinsp;\u0026lt;\u0026thinsp;0.05. All statistical analyses were performed using the JMP software (version 13; SAS Institute, Cary, NC, USA). Data were stored in a secure database, and patients were numerically coded for anonymity. The study protocol conformed to the ethical guidelines of the Declaration of Helsinki and was approved by the ethics committee of the Ehime University Graduate School of Medicine (#1705002, #1903007). The requirement for informed consent was waived due to the retrospective nature of the study, but the option to withdraw from the study was provided.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003ePatient background\u003c/h2\u003e \u003cp\u003eDuring the study period, 1,324 patients underwent 2,168 EUS. Analysis was carried out after 104 patients with 236 endoscopic procedures were excluded according to the exclusion criteria (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Patients who underwent EUS were divided into the former group (505 procedures, 409 patients) and the latter group (1,427 procedures, 918 patients). Patients who underwent EUS in both former and latter periods (107 patients) were assigned to both groups. The median age of patients in the latter EUS group was older than the former EUS group (66.4\u0026thinsp;\u0026plusmn;\u0026thinsp;11.9 vs. 68.9\u0026thinsp;\u0026plusmn;\u0026thinsp;10.7; P\u0026thinsp;\u0026lt;\u0026thinsp;0.01) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). There was no difference in sex distribution between the two groups: 49.9% and 53.4% of patients were male in the former group and the latter group, respectively (P\u0026thinsp;=\u0026thinsp;0.17).\u003c/p\u003e \u003cp\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\u003eBackground of the patients underwent EUS (N\u0026thinsp;=\u0026thinsp;1,932)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eThe former EUS group\u003c/p\u003e \u003cp\u003e(2009\u0026ndash;2014, N\u0026thinsp;=\u0026thinsp;505)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eThe latter EUS group\u003c/p\u003e \u003cp\u003e(2015\u0026ndash;2020, N\u0026thinsp;=\u0026thinsp;1,427)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e66.4\u0026thinsp;\u0026plusmn;\u0026thinsp;11.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68.9\u0026thinsp;\u0026plusmn;\u0026thinsp;10.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex (male)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e252 (49.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e762 (53.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.178\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrimary disease\u003c/p\u003e \u003cp\u003ePancreatic cyst\u003c/p\u003e \u003cp\u003ePancreatic cancer\u003c/p\u003e \u003cp\u003eBile duct cancer\u003c/p\u003e \u003cp\u003eBile duct stone\u003c/p\u003e \u003cp\u003eOther disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e198 (39.2%)\u003c/p\u003e \u003cp\u003e96 (19.0%)\u003c/p\u003e \u003cp\u003e30 (5.9%)\u003c/p\u003e \u003cp\u003e30 (5.9%)\u003c/p\u003e \u003cp\u003e151 (29.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e666 (46.6%)\u003c/p\u003e \u003cp\u003e227 (15.9%)\u003c/p\u003e \u003cp\u003e64 (4.4%)\u003c/p\u003e \u003cp\u003e34 (2.3%)\u003c/p\u003e \u003cp\u003e436 (30.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003cp\u003e0.110\u003c/p\u003e \u003cp\u003e0.187\u003c/p\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDescription of gastric finding\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 (2.97%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e568 (39.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIncidental gastric finding\u003c/p\u003e \u003cp\u003eCancer\u003c/p\u003e \u003cp\u003eMalignant lymphoma\u003c/p\u003e \u003cp\u003eAdenoma\u003c/p\u003e \u003cp\u003eSubmucosal tumor\u003c/p\u003e \u003cp\u003eUlcer\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.027\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eIndications for EUS and type of endoscopes\u003c/h2\u003e \u003cp\u003eThe indications for EUS were as follows: pancreatic cystic tumor (39.2%), pancreatic cancer (19.0%), bile duct cancer (5.9%), and bile duct stones (5.9%) in the former EUS group; and pancreatic cystic tumor (46.6%), pancreatic cancer (15.9%), bile duct cancer (4.4%), and bile duct stones (2.3%) in the latter EUS group. The latter group had more patients with pancreatic cystic tumors (P\u0026thinsp;=\u0026thinsp;0.004).\u003c/p\u003e \u003cp\u003eThe scopes used in the former group were EG-3670URK (N\u0026thinsp;=\u0026thinsp;311, 61.5%), EG-3870UTK (N\u0026thinsp;=\u0026thinsp;129, 25.5%) and others (N\u0026thinsp;=\u0026thinsp;65, 12.8%), whereas GF-UCT260 (N\u0026thinsp;=\u0026thinsp;1180, 82.6%), GF-UE260-AL5 (N\u0026thinsp;=\u0026thinsp;192, 13.4%) and others (N\u0026thinsp;=\u0026thinsp;55, 3.8%) were used in the latter group.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eIncidental finding of gastric lesions during EUS\u003c/h2\u003e \u003cp\u003eThirteen gastric lesions were incidentally found. The locations of the gastric lesions were as follows: lesser curvature of the gastric body (N\u0026thinsp;=\u0026thinsp;4) and the angular region (N\u0026thinsp;=\u0026thinsp;3), greater curvature of the pyloric antral zone (N\u0026thinsp;=\u0026thinsp;3), posterior wall of the gastric body (N\u0026thinsp;=\u0026thinsp;1) and the angular region (N\u0026thinsp;=\u0026thinsp;1), and pyloric ring (N\u0026thinsp;=\u0026thinsp;1). Two cases were gastric malignancies; the first was a 73-year-old man who underwent EUS (GF-UCT260) for intraductal papillary mucinous neoplasms (IPMNs) and was found to have early gastric cancer of 10mm in size of the lesser curvature of the gastric body (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eA). When this patient first underwent EUS, screening for gastric lesions had not yet been applied, and the lesions were detected on the next EUS when that was applied. The second was a 75-year-old man who underwent EUS (GF-UCT260) for jaundice of unknown origin and was found to have malignant lymphoma of the lesser curvature of the gastric body (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eB). The remaining ten cases were benign lesions: gastric adenoma (n\u0026thinsp;=\u0026thinsp;1), gastric submucosal tumor (n\u0026thinsp;=\u0026thinsp;2), and gastric ulcer (n\u0026thinsp;=\u0026thinsp;8).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAll incidental gastric lesions were in detected in the latter group. Therefore, the detection rate of gastric lesions was significantly higher in the latter group than in the former group per procedure (0.91% vs. 0%, P\u0026thinsp;=\u0026thinsp;0.027) and per patient (1.41% vs. 0%, P\u0026thinsp;=\u0026thinsp;0.015) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The primary diseases of the 13 patients (mean age 65.9 years) in whom incidental gastric lesions were found, and their odds ratio (OR) and 95% confidential interval (CI) were as follows: pancreatic cystic tumors (N\u0026thinsp;=\u0026thinsp;5, 38.5%) [IPMN (N\u0026thinsp;=\u0026thinsp;3, 23.0%), 2 SCN (N\u0026thinsp;=\u0026thinsp;2, 15.3%)]; OR\u0026thinsp;=\u0026thinsp;1.182 (95% CI\u0026thinsp;=\u0026thinsp;0.384\u0026ndash;3.635, P\u0026thinsp;=\u0026thinsp;0.769); pancreatic neuroendocrine neoplasms (p-NEN) (N\u0026thinsp;=\u0026thinsp;2, 15.3%), OR\u0026thinsp;=\u0026thinsp;46.4 (95% CI\u0026thinsp;=\u0026thinsp;8.112\u0026ndash;265.4, P\u0026thinsp;\u0026lt;\u0026thinsp;0.0001); biliary duct cancer (N\u0026thinsp;=\u0026thinsp;2, 15.3%), OR\u0026thinsp;=\u0026thinsp;1.149 (95% CI\u0026thinsp;=\u0026thinsp;0.252\u0026ndash;5.228, P\u0026thinsp;=\u0026thinsp;0.857); pancreatic cancer (N\u0026thinsp;=\u0026thinsp;1, 7.6%), OR\u0026thinsp;=\u0026thinsp;0.530 (95% CI\u0026thinsp;=\u0026thinsp;0.069\u0026ndash;4.103, P\u0026thinsp;=\u0026thinsp;0.536); and other pancreatobiliary diseases (N\u0026thinsp;=\u0026thinsp;3, 23.0%). Of the 13 cases of incidentally found gastric lesions, 11 were found on initial EUS. Of the remaining two cases, one was the case described above (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eA) and the other was an active gastric ulcer that occurred in a patient who had undergone multiple EUS procedures.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eDescription rate of gastric finding and incidental finding of gastric lesions\u003c/h2\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the annual change in description rate of gastric findings in medical record. A description of gastric findings during EUS was more significantly commonly documented in the medical records of patients in the latter group (568 of 1,427 examinations, 39.8%) than the former group (15 of 505 examinations, 2.97%) (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001, Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study evaluated the detection rate of gastric lesions during EUS. We found that the detection rate was 0% in the former EUS group, 0.91% in the latter EUS group (1.41% of patients). Therefore, increased awareness of gastric lesions during EUS might have helped improve the detection rate of gastric lesions.\u003c/p\u003e \u003cp\u003eThe incidental detection rate of gastric neoplasms during EUS is not well understood. Sahakian et al. reported that 2 out of 204 patients (0.98%) had neoplastic lesions detected during routine EGD before EUS [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In the prospective study of 368 patients, Wilcox reported that no patients had gastric malignancies when screened by duodenoscopy at ERCP [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In the latter EUS group in this study, we checked for gastric lesions in the visible area, and 2 of 918 patients (0.21%) with 1,427 procedures (0.14%) were found to have gastric malignancies. Considering that the detection rate of gastric cancer using forward-viewing endoscopes in the general population in Japan is 0.43\u0026ndash;0.87% [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], our detection rate was low, but it was not a negligible rate; therefore, any abnormal findings that are noted during investigations should be closely inspected and documented in the patients\u0026rsquo; endoscopy reports.\u003c/p\u003e \u003cp\u003eThere have been no reports on whether the detection rate increases with the presence or absence of awareness of incidental gastric lesions. Therefore, the impact of awareness on the incidental detection of gastric lesions is not understood. In this study, the detection rate of gastric lesions could be increased by brief screening of the stomach. Some studies comparing EUS/ERCP and EGD showed that there was no difference in the rate of missed gastric lesions [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. In contrast, Ashby et al. reported that ERCP or EUS followed by EGD resulted in an approximately 20% increase in the detection rate of gastric lesions [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Although there is no consensus on the difference in detection rates between oblique-viewing endoscopes and forward-viewing endoscopes, the blind area is greater in oblique-viewing endoscopes than in forward-viewing endoscopes. However, we found that performing a screening during EUS had a beneficial effect on the detection of incidental gastric lesions. Gastric screening requires insufflation. Empirically, CO\u003csub\u003e2\u003c/sub\u003e insufflation unlikely interfere with ultrasound observation if observed with degassing. As a result of recent advances in diagnostic imaging, the detection rate of pancreatic cysts such as IPMNs has increased and the opportunity for EUS has increased, and this was seen in the latter EUS group in this study. Gastric screening during EUS is especially important in IPMNs because some studies have shown an association between IPMNs and extrapancreatic malignancies [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Indeed, in this study, gastric cancer was also identified in an IPMN case. In addition, the OR of incidental detection rate on gastric lesion in p-NEN was significantly high. Therefore, gastric screening with attention to gastric lesion may be advisable when performing EUS for patients with p-NEN.\u003c/p\u003e \u003cp\u003eThis study has some limitations. First, our study population was elderly, and these results may not be generalizable to the population undergoing general health examinations. Second, because of the retrospective nature of the study, it is possible that patients who had undergone EGD prior to EUS may have been included. However, all 13 lesions noted in this study are new lesions, and we believe that this has an impact on the detection rate of gastric lesions. Third, since the ultrasound scopes used in the former and latter groups differed widely, it is necessary to consider whether there is an improvement in the lesion detection rate due to the improved observation of the scopes. The EG-3670URK, used in 61.5% of the former group, had a 140-degree field of view and a forward viewing. EG-3870UTK, used in 25.5% of the former group, had a 120-degree visual field angle and 45-degree anterior oblique viewing. In contrast, GF-UCT260, used in 82.6% of the latter group, had a 100-degree field of view and 55-degree anterior oblique viewing, and GF-UE260-AL5, used in 13.4% of the latter group, had a 100-degree field of view and 55-degree anterior oblique viewing. Although quantitative comparisons regarding image quality could not be determined, it is difficult to consider that the difference in the detection rate of gastric lesions is due to improved observation of the scopes, since the former group, which includes more straightforward views, is rather more beneficial in this optical observation. Fourth, the order of observation and the number of images taken are left to the endoscopists, and there are no rules. If rules were established, the detection rate might increase, but this would have the disadvantage of requiring more time. Nonetheless, quick gastric screening during EUS seems to be beneficial on detecting incidental gastric lesions.\u003c/p\u003e \u003cp\u003eIn conclusion, clinician awareness of detecting gastric lesions and the introduction of a quick screening during EUS improved the detection rate of gastric lesions. Further improvement in the description rate of gastric findings in medical records may even increase the detection rate of gastric lesions.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003e This work was supported in part by a grant from the Grant-in-Aid for Scientific Research (Japan Society for the Promotion of Science, KAKENHI 18K07469) provided to Dr Kumagi.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eStudy concept and design: YO (Okujima), TK (Kumagi), MK (Koizumi), TK (Kuroda), YI, KO. Acquisition: YO (Okujima), TK (Kumagi), MK (Koizumi), TK (Kuroda), YO (Ohno), YI, KO, KM, MK (Kokubu), YN, HY, NA, TY, YY, ET, YI, YH. Analysis: YO (Okujima), TK (Kumagi). Interpretation of data: YO (Okujima), TK (Kumagi). Statistical analysis: YO (Okujima), TK (Kumagi). Drafting of manuscript: YO (Okujima), TK (Kumagi), MK (Koizumi), TK (Kuroda), YO (Ohno), YI, KO, KM, MK (Kokubu), YN, HY, NA, TY, YY, ET, YI, YH. Important intellectual content and study supervision: TK (Kumagi), YH.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e \u003cp\u003eWe would like to thank Editage [\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.editage.com\u003c/span\u003e\u003cspan address=\"http://www.editage.com\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e] for editing and reviewing this manuscript for English language.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMaple JT, Ben-Menachem T, Anderson MA, et al. The role of endoscopy in the evaluation of suspected choledocholithiasis. Gastrointest Endosc. 2010; 71(1): 1\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIssa Y, Kempeneers MA, van Santvoort HC, Bollen TL, Bipat S, Boermeester MA. Diagnostic performance of imaging modalities in chronic pancreatitis: A systematic review and meta-analysis. Eur Radiol. 2017; 27(9): 3820\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eToft J, Hadden WJ, Laurence JM, et al. Imaging modalities in the diagnosis of pancreatic adenocarcinoma: A systematic review and meta-analysis of sensitivity, specificity and diagnostic accuracy. Eur J Radiol. 2017; 92:17\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJames PD, Meng ZW, Zhang M, et al. The incremental benefit of EUS for identifying unresectable disease among adults with pancreatic adenocarcinoma: A meta-analysis. PLoS One. 2017; 12(3): e0173687.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKrishna SG, Rao BB, Ugbarugba E, et al. Diagnostic performance of endoscopic ultrasound for detection of pancreatic malignancy following an indeterminate multidetector CT scan: A systemic review and meta-analysis. Surg Endosc. 2017; 31(11): 4558\u0026ndash;67.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJenssen C, Alvarez-S\u0026aacute;nchez MV, Napol\u0026eacute;on B, Faiss S. Diagnostic endoscopic ultrasonography: Assessment of safety and prevention of complications. World J Gastroenterol. 2012; 18(34): 4659\u0026ndash;76.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThomas A, Vamadevan AS, Slattery E, Sejpal DV, Trindade AJ. Performing forward-viewing endoscopy at time of pancreaticobiliary EUS and ERCP may detect additional upper gastrointestinal lesions. Endosc Int Open. 2016; 4(2): E193\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMachlowska J, Baj J, Sitarz M, Maciejewski R, Sitarz R. Gastric cancer: epidemiology, risk factors, classification, genomic characteristics and treatment strategies. Int J Mol Sci. 2020; 21(11): 4012.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJun JK, Choi KS, Lee HY, et al. Effectiveness of the Korean national cancer screening program in reducing gastric cancer mortality. Gatroenterology. 2017; 152(6): 1319\u0026ndash;1328.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHamashima C, Ogoshi K, Okamoto M, Shabana M, Kishimoto T, Fukao A. A community-based, case-control study evaluating mortality reduction from gastric cancer by endoscopic screening in Japan. PLoS One. 2013; 8(11): e79088.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHamashima C, Okamoto M, Shabana M, Osaki Y, Kishimoto T. Sensitivity of endoscopic screening for gastric cancer by the incidence method. Int. J. Cancer. 2013; 133(3): 653\u0026ndash;659.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKumagi T, Terao T, Yokota T, et al. Early detection of pancreatic cancer in patients with chronic liver disease under hepatocellular carcinoma surveillance. \u003cem\u003eMayo Clin Proc.\u003c/em\u003e 2019; 94(10): 2004\u0026ndash;2010.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSahakian AB, Aslanian HR, Mehra M, et al. The utility of esophagogastroduodenoscopy before endoscopic ultrasonography in patients undergoing endoscopic ultrasonography for pancreatico-biliary and mediastinal indications. J Clin Gastroenterol. 2013; 47(10): 857\u0026ndash;860.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilcox CM. Endoscopic examination with the duodenoscope at ERCP: frequency of lesions and accuracy of detection. Gastrointest Endosc. 2002; 55(4): 538\u0026ndash;542.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim S, Hamerski C, Ghassemi K, et al. The clinical utility of evaluating the luminal upper gastrointestinal tract during linear endoscopic ultrasonography. J Clin Gastroenterol. 2016; 50(7): 538\u0026ndash;544.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaiocchi GL, Molfino S, Frittoli B, et al. Increased risk of second malignancy in pancreatic intraductal papillary mucinous tumors: review of the literature. World J Gastroenterol. 2015; 21(23): 7313\u0026ndash;7319.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"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":"endoscopic ultrasonography, gastric screening, incidental finding, gastric lesions","lastPublishedDoi":"10.21203/rs.3.rs-3855715/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3855715/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eGastric lesions may be incidentally detected during endoscopic ultrasonography (EUS). We aimed to clarify the detection rate of gastric lesions and the impact of awareness on the detection of gastric lesions during EUS.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis retrospective study collected data on age, sex, primary pancreatobiliary disease, indication for EUS and detection of gastric lesions. The detection rate of incidental gastric lesions and documentation of gastric findings was compared between patients who underwent EUS (1,932 procedures, 1,220 patients). A quick gastric screening during EUS was introduced in 2015; therefore, EUS was classified into the former group (2009\u0026ndash;2014: 505 procedures, 409 patients) and the latter group (2015\u0026ndash;2020: 1,427 procedures, 918 patients).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThirteen gastric lesions were incidentally detected during EUS, all in the latter group, including gastric cancer (n\u0026thinsp;=\u0026thinsp;1), malignant lymphoma (n\u0026thinsp;=\u0026thinsp;1), gastric adenoma (n\u0026thinsp;=\u0026thinsp;1), gastric submucosal tumor (n\u0026thinsp;=\u0026thinsp;2), and gastric ulcer (n\u0026thinsp;=\u0026thinsp;8). The detection rate of gastric lesions was significantly higher in the latter group than in the former group per procedure (0.91% vs. 0%, P\u0026thinsp;=\u0026thinsp;0.027) and per patient (1.41% vs. 0%, P\u0026thinsp;=\u0026thinsp;0.015), and gastric findings were significantly more commonly described in patients\u0026rsquo; medical records (39.8% vs. 2.97%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eGastric lesions may be encountered during EUS. A quick screening during EUS improved the detection rate of gastric lesions, presumably due to increased awareness of gastric lesions during the procedure.\u003c/p\u003e","manuscriptTitle":"Incidental finding of gastric lesions during endoscopic ultrasonography","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-01-15 21:02:34","doi":"10.21203/rs.3.rs-3855715/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":"215abcf9-5960-4efd-b36d-fd985372be6a","owner":[],"postedDate":"January 15th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-01-17T21:15:24+00:00","versionOfRecord":[],"versionCreatedAt":"2024-01-15 21:02:34","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3855715","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3855715","identity":"rs-3855715","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}