Identifying immune-related predictive factors for post-eribulin therapy in patients with HER2-negative advanced breast cancer- A multicenter retrospective study

Identifying immune-related predictive factors for post-eribulin therapy in patients with HER2-negative advanced breast cancer- A multicenter retrospective study | 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 Identifying immune-related predictive factors for post-eribulin therapy in patients with HER2-negative advanced breast cancer- A multicenter retrospective study Yuri Takamatsu, Yoshiya Horimoto, Yasuo Miyoshi, Junichiro Watanabe, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7341073/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: In the EMBRACE study, eribulin (ERI) monotherapy improved the overall survival (OS) of patients with HER2-negative advanced breast cancer (HER2-ABC). A post hoc analysis identified the baseline absolute lymphocyte count (ALC) as a predictive marker in the ERI arm. We focused on factors at the termination of treatment that had not been considered previously. Methods: We retrospectively analyzed 370 patients receiving ERI for HER2-ABC between July 2011 and June 2024 across 3 institutions. Clinical data, including the ALC, neutrophil-to-lymphocyte ratio (NLR), and other factors, were extracted from medical records. Statistical analyses included the log-rank test and Cox hazard model. The OS was defined as the survival from the initiation of ERI (OS1) and from the termination of ERI (OS2). Results: In the univariate analysis, the OS1 was longer in patients > 65 years old, ER-positive, and with ALC > 1000/μL at ERI initiation than in others, and the OS2 was longer in ER-positive cases with an ERI time-to-treatment-discontinuation (TTD) > 120 days and ALC > 1000/μL at ERI completion. In the multivariate analysis, ER positivity and baseline ALC > 1000/μL remained associated with a longer OS1. ALC > 1000/μL at ERI completion and an ERI TTD > 120 days remained associated with a longer OS2. In the first-line ERI group, the ALC was maintained during ERI administration, whereas in those who received other treatments, it significantly decreased ( p 1000/μL at ERI completion was associated with an improved post-ERI OS. Maintaining the ALC during ERI administration may be associated with a favorable prognosis. Breast Cancer Eribulin Predictive marker Absolute lymphocyte count Figures Figure 1 Figure 2 Introduction Advanced breast cancer (ABC) is considered incurable, and its treatment primarily consists of long-term drug therapy. Although multiple therapeutic options exist, determining the optimal drug selection and sequencing remains a challenge. Treatment decisions are based on factors such as patient age and metastatic status; however, there is no clear evidence guiding the order of administration in later-line settings. Therefore, there is a need for predictive markers of cytotoxic agents to optimize treatment strategies and improve patient outcomes. Eribulin (ERI), a microtubule inhibitor derived from marine sponges, is widely used in patients with inoperable or recurrent breast cancer who have previously received chemotherapy [ 1 ]. The EMBRACE study demonstrated that ERI monotherapy significantly improved the overall survival (OS) of patients with HER2-negative ABC compared to treatment based on the physician’s choice [ 2 ]. In addition, the RESQ study found that ERI, when used as first- or second-line chemotherapy for HER2-negative ABC, significantly prolonged the OS compared to S-1, a 5-fluorouracil derivative [ 3 ]. Peripheral blood markers, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and absolute lymphocyte count (ALC), have been established as prognostic indicators in breast cancer [ 4 ], [ 5 ], [ 6 ]. Several studies have also investigated predictive markers of ERI treatment. We previously reported that a higher NLR is associated with a shorter duration of ERI treatment [ 7 ]. A post hoc analysis of the aforementioned EMBRACE study identified baseline ALC as a biomarker for ERI [ 8 ]. Furthermore, in patients with ER-positive ABC, a baseline ALC ≥ 1000/µL was significantly associated with a prolonged OS following ERI treatment [ 9 ]. However, no study has yet reported the predictive factors for OS after the completion of ERI. As treatment for ABC often continues beyond ERI treatment, identifying prognostic markers for the post-ERI survival might help optimize subsequent treatment strategies, including the transition to best supportive care (BSC). We therefore attempted to predict the prognosis after ERI treatment using the initial and final treatment day information available at the time of its administration. Patients and methods Patients We retrospectively reviewed the medical records of HER2-negative ABC patients who received ERI monotherapy between July 2011 and June 2024 at three institutions (Shizuoka Cancer Center, Hyogo College of Medicine, and Juntendo University Hospital). The study was approved by the institutional review board of Shizuoka Cancer Center (#T2019-33-2019-1-4) and Juntendo University Hospital (H19-0289). The need for written informed consent was waived due to the retrospective nature of the study. Pathological diagnoses Pathological examinations of the primary tumors were performed by experienced pathologists at each institution. The histological type was determined based on the WHO Classification of Tumors of the Breast (5th edition). The nuclear grade (NG) was evaluated using the modified Bloom-Richardson histologic grading system [ 10 ]. ER and PgR statuses were assessed semi-quantitatively and reported as positive when more than 1% of the nuclei of the cancer cells showed staining. HER2 was judged to be positive if more than 10% of tumor cells showed strong staining of the entire cell membrane or HER2/neu gene amplification was confirmed by fluorescence in situ hybridization, and HER2-positive cases were excluded from this study. Peripheral blood tests and the calculation of immune-related parameters Whole blood samples were drawn from patients on the day of the planned administration of ERI or within seven days before administration. Complete blood counts were performed using the Sysmex XN-3100 or XE-5000 automated hematology system (Sysmex Co., Kobe, Japan). The ALC and NLR were measured from blood test data obtained on the first and last ERI administration days. As there are no established absolute cutoff values for evaluating factors related to the OS, we adopted cutoff values of 1000/µL for the ALC [ 9 ] and 3 for the NLR [ 11 ] [ 8 ], based on previous studies. Treatments ERI was administered at 1.4 mg/m 2 on days 1 and 8 of the 3-week cycle. In cases of neutropenia or toxicity, the dose was reduced or changed to biweekly administration. We defined the time to treatment discontinuation (TTD) as the period from ERI treatment initiation to the last ERI treatment day. In this study, we defined the OS as follows: OS1, survival from the initiation of ERI to death from any cause; and OS2, survival from the termination of ERI therapy to death from any cause (Fig. 1 ). Statistical analyses The JMP Pro 17 software program, Japanese version (JMP Statistical Discovery LLC, San Francisco, CA, USA), was used for the statistical analyses. A Cox proportional hazards model was used for the OS analyses. For the full-model analysis, we selected the age, tumor grade, ER status, presence of visceral metastasis, ALC, and ERI-TTD, considering their clinical significance. Statistical significance was set at p < 0.05. Results Patients’ background characteristics In total, data from 370 patients were available; the clinicopathological features of these patients are shown in Table 1. The median patient age at the time of ERI initiation was 59 (30–86) years old. Visceral metastasis developed in 60.8% of patients. ERI was administered as second-line therapy in the median. Clinical data, including peripheral blood markers, were extracted from the medical records and, as shown below, analyzed for their association with patient outcomes. Association of clinicopathological factors with the OS1 and OS2 A univariate analysis revealed that patients ≥ 65 years old, those with ER-positive tumors, and those with an ALC > 1000/µL at ERI initiation had a significantly longer OS1 than others ( p = 0.045, p < 0.001, and p 3 had a significantly shorter OS1 than others ( p = 0.026, p = 0.001, and p 1000/µL remained independent factors associated with a longer OS1 ( p = 0.033 and p 120 days, and ALC > 1000/µL at the last ERI administration were significantly associated with a longer OS2 ( p < 0.001, p < 0.001, and p 3 were associated with a significantly shortened OS2 ( p = 0.004 and p 1000/µL at the last ERI administration and ERI TTD > 120 days remained independent factors associated with a significantly extended OS2 ( p < 0.001 and p = 0.036, respectively). ALC trends in the group treated with ERI as first-line therapy for recurrence As the aforementioned analysis demonstrated that patients with a higher ALC tended to have a longer survival, we speculated that the survival benefit of ERI may be due to its minimal effect on the ALC, which can help maintain eligibility for subsequent treatments. However, in the present study, ERI was administered as various lines of therapy (median, 2; range: 1–9). Therefore, we conducted an additional analysis of ALC levels throughout ERI treatment in a subgroup of patients who received ERI as first-line chemotherapy for ABC. As a control, we selected patients who received other anticancer agents as the first-line treatment and compared the results. Notably, in patients who received ERI as first-line chemotherapy (n = 61), the mean ALC at the first and final administration was 1,316 and 1,343/µL, respectively, indicating that ALC was well maintained during treatment ( p = 0.801, Fig. 2 A). In contrast, in the group that received non-ERI agents as first-line chemotherapy (n = 219), the mean ALC decreased from 1,452/µL at the first administration to 1,293/µL at the final administration, showing a significant reduction ( p = 0.003, Fig. 2 B). Discussion In the present study, ALC values of ≥ 1000/µL were associated with a prolonged OS1, even in a multivariate analysis. In other words, consistent with previous reports, constant ALC values at the initiation of ERI were associated with a favorable OS [ 8 ] [ 12 ] [ 13 ]. We additionally targeted the OS2 in the present study, which is the OS after ERI administration, and investigated the factors that prolong the OS. The results showed that maintaining an ALC of ≥ 1,000/µL prolonged not only the OS1 but also the OS2. Su et al. [ 14 ] reported that a high ALC at baseline and three months after ERI initiation were associated with a prolonged OS, consistent with our findings that maintaining a high ALC after ERI administration is associated with an improved OS. Looking at the OS2 in the aforementioned EMBRACE trial, there was only a one-month difference between the ERI and treatment of physician’s choice groups [ 2 ]. In general, the ALC gradually decreases during the treatment of recurrent breast cancer. We previously reported that ALC gradually declined as the disease progressed, showing a significant decrease at the time of transition to BSC compared with that at the time of the ABC diagnosis [ 6 ]. In the present study of 370 cases, we compared changes in the ALC between patients who received ERI as first-line chemotherapy and those who received other treatments initially. The results showed that the ALC was maintained in the ERI group, suggesting that ERI may help maintain the ALC during treatment. Keeping the ALC high may allow for adequate treatment after ERI administration, potentially leading to an improved OS. ERI is reported to improve the tumor microenvironment (TME), such as re-oxygenation within tumors, by remodeling the tumor vasculature [ 15 ]. Improvements in the TME, particularly in overcoming immune suppression, may contribute to enhanced local and systemic antitumor immunity and help maintain a favorable immune state [ 16 ]. Furthermore, a meta-analysis of ERI hematotoxicity [ 17 ] showed a significant risk of neutropenia, with relatively mild effects on other blood cell lines such as platelets, suggesting that bone marrow suppression is largely limited to the granulocyte lineage. Although subsets of T-lymphocytes were not examined in this meta-analysis, ERI may have minimal impact on long-lived or mature T-lymphocytes due to its mode of action as a tubulin inhibitor. ERI is a drug that can be flexibly administered according to the degree of bone marrow suppression without compromising its efficacy due to its pharmacological properties[ 18 ], which may allow the maintenance of lymphocyte counts. Nevertheless, further detailed investigations are needed to elucidate the mechanism by which ERI maintains the ALC. Several limitations associated with the present study warrant mention. First, an individual’s ALC may remain high simply due to genetic predisposition; however, this cannot be verified at present. Second, our study only included Japanese patients. Thus, based on previous research results [ 9 ] and the average ALC value of 1,423/µL observed at the start of first-line chemotherapy in this study, a cutoff value of 1,000/µL was set. An appropriate cutoff value has not yet been established, and this remains a topic for future research. Finally, the study was conducted retrospectively; therefore, some bias, such as the judgment of disease progression or intolerable toxicity based on institutional criteria, could not be excluded. Conclusion Maintaining ALC during ERI administration was associated with an improved OS. The ALC may be useful as a prognostic factor when ERI administration is discontinued regardless of clinical judgment. Declarations Acknowledgement Part of the study was presented at the Advanced Breast Cancer Consensus Conference 7 (Lisbon, Portugal) and the 2025 San Antonio Breast Cancer Symposium (San Antonio, TX) as poster presentations. Author Contributions Study concept and design: YH, YM, JW. Data acquisition: YT, YH, YM, JW. Data analysis: YT, YH. Data interpretation: YT, YH, YM, JW. Drafting or critically revising manuscript: YT, YH, JW. Approval of final version: All authors. Data sharing The authors will share the study data upon reasonable request. Conflict of interest YM and JW receive lecture fees from Eisai. All other authors have no relevant financial or non-financial interests to disclose. Ethics approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the Ethics Committee of Juntendo University Hospital (H16-0096-H01) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Consent to participate An opt-out approach was used with the disclosure of website. Consent to publish Not applicable. References Garrone O et al (2017) Eribulin in advanced breast cancer: safety, efficacy and new perspectives. Future Oncol 13(30):2759–2769 Cortes J et al (2011) Eribulin monotherapy versus treatment of physician's choice in patients with metastatic breast cancer (EMBRACE): a phase 3 open-label randomised study. Lancet 377(9769):914–923 Takahashi M et al (2024) Eribulin versus S-1 as first or second-line chemotherapy to assess health-related quality of life and overall survival in HER2-negative metastatic breast cancer (RESQ study): a non-inferiority, randomised, controlled, open-label, phase 3 trial. EClinicalMedicine 74:102715 Koh CH et al (2015) Utility of pre-treatment neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as prognostic factors in breast cancer. Br J Cancer 113(1):150–158 Krenn-Pilko S et al (2014) The elevated preoperative platelet-to-lymphocyte ratio predicts poor prognosis in breast cancer patients. Br J Cancer 110(10):2524–2530 Jimbo H et al (2022) Absolute lymphocyte count decreases with disease progression and is a potential prognostic marker for metastatic breast cancer. Breast Cancer Res Treat 196(2):291–298 Myojin M et al (2020) Neutrophil-to-lymphocyte ratio and histological type might predict clinical responses to eriburin-based treatment in patients with metastatic breast cancer. Breast Cancer 27(4):732–738 Miyoshi Y et al (2020) High absolute lymphocyte counts are associated with longer overall survival in patients with metastatic breast cancer treated with eribulin-but not with treatment of physician's choice-in the EMBRACE study. Breast Cancer 27(4):706–715 Watanabe J et al (2020) A maintained absolute lymphocyte count predicts the overall survival benefit from eribulin therapy, including eribulin re-administration, in HER2-negative advanced breast cancer patients: a single-institutional experience. Breast Cancer Res Treat 181(1):211–220 Elston CW, Ellis IO (1991) Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up. Histopathology 19(5):403–410 Asano Y et al (2016) Predictive Value of Neutrophil/Lymphocyte Ratio for Efficacy of Preoperative Chemotherapy in Triple-Negative Breast Cancer. Ann Surg Oncol 23(4):1104–1110 Koyama Y et al (2021) Absolute Lymphocyte Count, Platelet-to-Lymphocyte Ratio, and Overall Survival in Eribulin-treated HER2-negative Metastatic Breast Cancer Patients. Cancer Diagn Progn 1(5):435–441 Nakamoto S et al (2021) Dynamic Changes in Absolute Lymphocyte Counts During Eribulin Therapy Are Associated With Survival Benefit. Anticancer Res 41(6):3109–3119 Su MX et al (2024) Monitoring trends in the absolute lymphocyte count and the neutrophil-to-lymphocyte ratio in patients with breast cancer receiving eribulin. BMC Cancer 24(1):195 Funahashi Y et al (2014) Eribulin mesylate reduces tumor microenvironment abnormality by vascular remodeling in preclinical human breast cancer models. Cancer Sci 105(10):1334–1342 Joyce JA, Fearon DT (2015) T cell exclusion, immune privilege, and the tumor microenvironment. Science 348(6230):74–80 Zhao B, Zhao H (2017) Incidence and risk of eribulin mesylate related hematologic toxicity. Oncotarget Ohtani S et al (2018) Bi-weekly eribulin therapy for metastatic breast cancer: a multicenter phase II prospective study (JUST-STUDY). Breast Cancer 25(4):438–446 Tables Tables 1 to 3 are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table1.jpg Table2.jpg Table3.jpg 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. 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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-7341073","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":512329500,"identity":"7ff30e2e-7058-4888-bcf3-721911d874a5","order_by":0,"name":"Yuri Takamatsu","email":"","orcid":"","institution":"Juntendo University","correspondingAuthor":false,"prefix":"","firstName":"Yuri","middleName":"","lastName":"Takamatsu","suffix":""},{"id":512329501,"identity":"e13526f2-3e4c-4be3-9bac-fe2b25ef4073","order_by":1,"name":"Yoshiya Horimoto","email":"","orcid":"","institution":"Juntendo University","correspondingAuthor":false,"prefix":"","firstName":"Yoshiya","middleName":"","lastName":"Horimoto","suffix":""},{"id":512329502,"identity":"729f9710-052b-490b-9061-c52a664ef682","order_by":2,"name":"Yasuo Miyoshi","email":"","orcid":"","institution":"Hyogo Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yasuo","middleName":"","lastName":"Miyoshi","suffix":""},{"id":512329503,"identity":"9b232fc7-5a21-4ab1-a6dd-c961c0ac52cb","order_by":3,"name":"Junichiro Watanabe","email":"data:image/png;base64,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","orcid":"","institution":"Juntendo University","correspondingAuthor":true,"prefix":"","firstName":"Junichiro","middleName":"","lastName":"Watanabe","suffix":""},{"id":512329504,"identity":"76b6e4a6-9b77-48bc-a04d-fd2fa253de14","order_by":4,"name":"Goro Kutomi","email":"","orcid":"","institution":"Juntendo University","correspondingAuthor":false,"prefix":"","firstName":"Goro","middleName":"","lastName":"Kutomi","suffix":""}],"badges":[],"createdAt":"2025-08-10 22:53:08","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7341073/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7341073/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":91073465,"identity":"23604d1c-6ef7-4465-b631-7ead719f3b8b","added_by":"auto","created_at":"2025-09-11 10:58:34","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":64264,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eBlood sampling schedule and definition of survival periods in patients treated with ERI.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Fig1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7341073/v1/5143ee682e911f5ffe1c6b00.jpg"},{"id":91073467,"identity":"3e930de5-290c-4790-85e8-76450fd314ff","added_by":"auto","created_at":"2025-09-11 10:58:34","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":63386,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eChanges in ALC during first-line chemotherapy for advanced breast cancer.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(A) Transition of ALC in patients receiving ERI as first-line chemotherapy for ABC.\u003c/p\u003e\n\u003cp\u003e(B) Transition of ALC in patients receiving non-ERI regimens as first-line chemotherapy. Red bars represent ALC on the first day of treatment; blue bars represent ALC on the last day of treatment.\u003c/p\u003e","description":"","filename":"Fig2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7341073/v1/f8dd1aa938ae6d5dd5a882df.jpg"},{"id":92124919,"identity":"938a7a61-3f57-4eef-9485-8c677d0e6347","added_by":"auto","created_at":"2025-09-25 01:01:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":742104,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7341073/v1/57d8d657-574b-42d9-b96d-24d2d352b47f.pdf"},{"id":91073466,"identity":"4466df37-20c3-4c77-8cb5-77a427f41b39","added_by":"auto","created_at":"2025-09-11 10:58:34","extension":"jpg","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":117681,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7341073/v1/70c9d9d91ddd3ee76f99edcc.jpg"},{"id":91073470,"identity":"6ca22958-d504-4fcb-a317-b50465cccf71","added_by":"auto","created_at":"2025-09-11 10:58:34","extension":"jpg","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":163266,"visible":true,"origin":"","legend":"","description":"","filename":"Table2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7341073/v1/5ddbd7f4b9a78cbd0f40aac9.jpg"},{"id":91073474,"identity":"cfe470e5-4585-4e7a-ad64-6c925c2de7c4","added_by":"auto","created_at":"2025-09-11 10:58:34","extension":"jpg","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":177749,"visible":true,"origin":"","legend":"","description":"","filename":"Table3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7341073/v1/33262e820c0ac5915638fe43.jpg"}],"financialInterests":"No competing interests reported.","formattedTitle":"Identifying immune-related predictive factors for post-eribulin therapy in patients with HER2-negative advanced breast cancer- A multicenter retrospective study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAdvanced breast cancer (ABC) is considered incurable, and its treatment primarily consists of long-term drug therapy. Although multiple therapeutic options exist, determining the optimal drug selection and sequencing remains a challenge. Treatment decisions are based on factors such as patient age and metastatic status; however, there is no clear evidence guiding the order of administration in later-line settings. Therefore, there is a need for predictive markers of cytotoxic agents to optimize treatment strategies and improve patient outcomes.\u003c/p\u003e\u003cp\u003eEribulin (ERI), a microtubule inhibitor derived from marine sponges, is widely used in patients with inoperable or recurrent breast cancer who have previously received chemotherapy [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The EMBRACE study demonstrated that ERI monotherapy significantly improved the overall survival (OS) of patients with HER2-negative ABC compared to treatment based on the physician\u0026rsquo;s choice [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In addition, the RESQ study found that ERI, when used as first- or second-line chemotherapy for HER2-negative ABC, significantly prolonged the OS compared to S-1, a 5-fluorouracil derivative [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003ePeripheral blood markers, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and absolute lymphocyte count (ALC), have been established as prognostic indicators in breast cancer [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Several studies have also investigated predictive markers of ERI treatment. We previously reported that a higher NLR is associated with a shorter duration of ERI treatment [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. A \u003cem\u003epost hoc\u003c/em\u003e analysis of the aforementioned EMBRACE study identified baseline ALC as a biomarker for ERI [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Furthermore, in patients with ER-positive ABC, a baseline ALC\u0026thinsp;\u0026ge;\u0026thinsp;1000/\u0026micro;L was significantly associated with a prolonged OS following ERI treatment [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. However, no study has yet reported the predictive factors for OS after the completion of ERI. As treatment for ABC often continues beyond ERI treatment, identifying prognostic markers for the post-ERI survival might help optimize subsequent treatment strategies, including the transition to best supportive care (BSC).\u003c/p\u003e\u003cp\u003eWe therefore attempted to predict the prognosis after ERI treatment using the initial and final treatment day information available at the time of its administration.\u003c/p\u003e"},{"header":"Patients and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003ePatients\u003c/h2\u003e\u003cp\u003e We retrospectively reviewed the medical records of HER2-negative ABC patients who received ERI monotherapy between July 2011 and June 2024 at three institutions (Shizuoka Cancer Center, Hyogo College of Medicine, and Juntendo University Hospital). The study was approved by the institutional review board of Shizuoka Cancer Center (#T2019-33-2019-1-4) and Juntendo University Hospital (H19-0289). The need for written informed consent was waived due to the retrospective nature of the study.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003ePathological diagnoses\u003c/h3\u003e\n\u003cp\u003ePathological examinations of the primary tumors were performed by experienced pathologists at each institution. The histological type was determined based on the WHO Classification of Tumors of the Breast (5th edition). The nuclear grade (NG) was evaluated using the modified Bloom-Richardson histologic grading system [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. ER and PgR statuses were assessed semi-quantitatively and reported as positive when more than 1% of the nuclei of the cancer cells showed staining. HER2 was judged to be positive if more than 10% of tumor cells showed strong staining of the entire cell membrane or \u003cem\u003eHER2/neu\u003c/em\u003e gene amplification was confirmed by fluorescence \u003cem\u003ein situ\u003c/em\u003e hybridization, and HER2-positive cases were excluded from this study.\u003c/p\u003e\n\u003ch3\u003ePeripheral blood tests and the calculation of immune-related parameters\u003c/h3\u003e\n\u003cp\u003eWhole blood samples were drawn from patients on the day of the planned administration of ERI or within seven days before administration. Complete blood counts were performed using the Sysmex XN-3100 or XE-5000 automated hematology system (Sysmex Co., Kobe, Japan).\u003c/p\u003e\u003cp\u003eThe ALC and NLR were measured from blood test data obtained on the first and last ERI administration days. As there are no established absolute cutoff values for evaluating factors related to the OS, we adopted cutoff values of 1000/\u0026micro;L for the ALC [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] and 3 for the NLR [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], based on previous studies.\u003c/p\u003e\n\u003ch3\u003eTreatments\u003c/h3\u003e\n\u003cp\u003eERI was administered at 1.4 mg/m\u003csup\u003e2\u003c/sup\u003e on days 1 and 8 of the 3-week cycle. In cases of neutropenia or toxicity, the dose was reduced or changed to biweekly administration. We defined the time to treatment discontinuation (TTD) as the period from ERI treatment initiation to the last ERI treatment day. In this study, we defined the OS as follows: OS1, survival from the initiation of ERI to death from any cause; and OS2, survival from the termination of ERI therapy to death from any cause (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\n\u003ch3\u003eStatistical analyses\u003c/h3\u003e\n\u003cp\u003eThe JMP Pro 17 software program, Japanese version (JMP Statistical Discovery LLC, San Francisco, CA, USA), was used for the statistical analyses. A Cox proportional hazards model was used for the OS analyses. For the full-model analysis, we selected the age, tumor grade, ER status, presence of visceral metastasis, ALC, and ERI-TTD, considering their clinical significance. Statistical significance was set at \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003ePatients\u0026rsquo; background characteristics\u003c/h2\u003e\u003cp\u003eIn total, data from 370 patients were available; the clinicopathological features of these patients are shown in Table\u0026nbsp;1. The median patient age at the time of ERI initiation was 59 (30\u0026ndash;86) years old. Visceral metastasis developed in 60.8% of patients. ERI was administered as second-line therapy in the median.\u003c/p\u003e\u003cp\u003eClinical data, including peripheral blood markers, were extracted from the medical records and, as shown below, analyzed for their association with patient outcomes.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eAssociation of clinicopathological factors with the OS1 and OS2\u003c/h3\u003e\n\u003cp\u003eA univariate analysis revealed that patients\u0026thinsp;\u0026ge;\u0026thinsp;65 years old, those with ER-positive tumors, and those with an ALC\u0026thinsp;\u0026gt;\u0026thinsp;1000/\u0026micro;L at ERI initiation had a significantly longer OS1 than others (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.045, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001, and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001, respectively; Table\u0026nbsp;2). In contrast, patients with \u003cem\u003ede novo\u003c/em\u003e stage 4 BC, a high NG, or baseline NLR\u0026thinsp;\u0026gt;\u0026thinsp;3 had a significantly shorter OS1 than others (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.026, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001, and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001, respectively). In the multivariate analysis, ER positivity and baseline ALC\u0026thinsp;\u0026gt;\u0026thinsp;1000/\u0026micro;L remained independent factors associated with a longer OS1 (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.033 and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001, respectively).\u003c/p\u003e\u003cp\u003eIn addition, a univariate analysis showed that ER positivity, ERI TTD\u0026thinsp;\u0026gt;\u0026thinsp;120 days, and ALC\u0026thinsp;\u0026gt;\u0026thinsp;1000/\u0026micro;L at the last ERI administration were significantly associated with a longer OS2 (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001, and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001, respectively; Table\u0026nbsp;3). In contrast, a high NG and NLR\u0026thinsp;\u0026gt;\u0026thinsp;3 were associated with a significantly shortened OS2 (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.004 and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001, respectively). In the multivariate analysis, an ALC\u0026thinsp;\u0026gt;\u0026thinsp;1000/\u0026micro;L at the last ERI administration and ERI TTD\u0026thinsp;\u0026gt;\u0026thinsp;120 days remained independent factors associated with a significantly extended OS2 (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.036, respectively).\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eALC trends in the group treated with ERI as first-line therapy for recurrence\u003c/h2\u003e\u003cp\u003eAs the aforementioned analysis demonstrated that patients with a higher ALC tended to have a longer survival, we speculated that the survival benefit of ERI may be due to its minimal effect on the ALC, which can help maintain eligibility for subsequent treatments. However, in the present study, ERI was administered as various lines of therapy (median, 2; range: 1\u0026ndash;9). Therefore, we conducted an additional analysis of ALC levels throughout ERI treatment in a subgroup of patients who received ERI as first-line chemotherapy for ABC. As a control, we selected patients who received other anticancer agents as the first-line treatment and compared the results.\u003c/p\u003e\u003cp\u003eNotably, in patients who received ERI as first-line chemotherapy (n\u0026thinsp;=\u0026thinsp;61), the mean ALC at the first and final administration was 1,316 and 1,343/\u0026micro;L, respectively, indicating that ALC was well maintained during treatment (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.801, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA). In contrast, in the group that received non-ERI agents as first-line chemotherapy (n\u0026thinsp;=\u0026thinsp;219), the mean ALC decreased from 1,452/\u0026micro;L at the first administration to 1,293/\u0026micro;L at the final administration, showing a significant reduction (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.003, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn the present study, ALC values of \u0026ge;\u0026thinsp;1000/\u0026micro;L were associated with a prolonged OS1, even in a multivariate analysis. In other words, consistent with previous reports, constant ALC values at the initiation of ERI were associated with a favorable OS [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. We additionally targeted the OS2 in the present study, which is the OS after ERI administration, and investigated the factors that prolong the OS. The results showed that maintaining an ALC of \u0026ge;\u0026thinsp;1,000/\u0026micro;L prolonged not only the OS1 but also the OS2. Su et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] reported that a high ALC at baseline and three months after ERI initiation were associated with a prolonged OS, consistent with our findings that maintaining a high ALC after ERI administration is associated with an improved OS. Looking at the OS2 in the aforementioned EMBRACE trial, there was only a one-month difference between the ERI and treatment of physician\u0026rsquo;s choice groups [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn general, the ALC gradually decreases during the treatment of recurrent breast cancer. We previously reported that ALC gradually declined as the disease progressed, showing a significant decrease at the time of transition to BSC compared with that at the time of the ABC diagnosis [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. In the present study of 370 cases, we compared changes in the ALC between patients who received ERI as first-line chemotherapy and those who received other treatments initially. The results showed that the ALC was maintained in the ERI group, suggesting that ERI may help maintain the ALC during treatment. Keeping the ALC high may allow for adequate treatment after ERI administration, potentially leading to an improved OS.\u003c/p\u003e\u003cp\u003eERI is reported to improve the tumor microenvironment (TME), such as re-oxygenation within tumors, by remodeling the tumor vasculature [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Improvements in the TME, particularly in overcoming immune suppression, may contribute to enhanced local and systemic antitumor immunity and help maintain a favorable immune state [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Furthermore, a meta-analysis of ERI hematotoxicity [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] showed a significant risk of neutropenia, with relatively mild effects on other blood cell lines such as platelets, suggesting that bone marrow suppression is largely limited to the granulocyte lineage. Although subsets of T-lymphocytes were not examined in this meta-analysis, ERI may have minimal impact on long-lived or mature T-lymphocytes due to its mode of action as a tubulin inhibitor. ERI is a drug that can be flexibly administered according to the degree of bone marrow suppression without compromising its efficacy due to its pharmacological properties[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], which may allow the maintenance of lymphocyte counts. Nevertheless, further detailed investigations are needed to elucidate the mechanism by which ERI maintains the ALC.\u003c/p\u003e\u003cp\u003eSeveral limitations associated with the present study warrant mention. First, an individual\u0026rsquo;s ALC may remain high simply due to genetic predisposition; however, this cannot be verified at present. Second, our study only included Japanese patients. Thus, based on previous research results [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] and the average ALC value of 1,423/\u0026micro;L observed at the start of first-line chemotherapy in this study, a cutoff value of 1,000/\u0026micro;L was set. An appropriate cutoff value has not yet been established, and this remains a topic for future research. Finally, the study was conducted retrospectively; therefore, some bias, such as the judgment of disease progression or intolerable toxicity based on institutional criteria, could not be excluded.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eMaintaining ALC during ERI administration was associated with an improved OS. The ALC may be useful as a prognostic factor when ERI administration is discontinued regardless of clinical judgment.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePart of the study was presented at the Advanced Breast Cancer Consensus Conference 7 (Lisbon, Portugal) and the 2025 San Antonio Breast Cancer Symposium (San Antonio, TX) as poster presentations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eStudy concept and design: YH, YM, JW. Data acquisition: YT, YH, YM, JW. Data analysis: YT, YH. Data interpretation: YT, YH, YM, JW. Drafting or critically revising manuscript: YT, YH, JW. Approval of final version: All authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData sharing\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors will share the study data upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e YM and JW receive lecture fees from Eisai. All other authors have no relevant financial or non-financial interests to disclose.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e All procedures performed in studies involving human participants were in accordance with the ethical standards of the Ethics Committee of Juntendo University Hospital (H16-0096-H01) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate\u003c/strong\u003e An opt-out approach was used with the disclosure of website.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to publish\u003c/strong\u003e Not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cbr\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eGarrone O et al (2017) Eribulin in advanced breast cancer: safety, efficacy and new perspectives. Future Oncol 13(30):2759\u0026ndash;2769\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCortes J et al (2011) Eribulin monotherapy versus treatment of physician's choice in patients with metastatic breast cancer (EMBRACE): a phase 3 open-label randomised study. Lancet 377(9769):914\u0026ndash;923\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTakahashi M et al (2024) Eribulin versus S-1 as first or second-line chemotherapy to assess health-related quality of life and overall survival in HER2-negative metastatic breast cancer (RESQ study): a non-inferiority, randomised, controlled, open-label, phase 3 trial. EClinicalMedicine 74:102715\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKoh CH et al (2015) Utility of pre-treatment neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as prognostic factors in breast cancer. Br J Cancer 113(1):150\u0026ndash;158\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKrenn-Pilko S et al (2014) The elevated preoperative platelet-to-lymphocyte ratio predicts poor prognosis in breast cancer patients. Br J Cancer 110(10):2524\u0026ndash;2530\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJimbo H et al (2022) Absolute lymphocyte count decreases with disease progression and is a potential prognostic marker for metastatic breast cancer. Breast Cancer Res Treat 196(2):291\u0026ndash;298\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMyojin M et al (2020) Neutrophil-to-lymphocyte ratio and histological type might predict clinical responses to eriburin-based treatment in patients with metastatic breast cancer. Breast Cancer 27(4):732\u0026ndash;738\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMiyoshi Y et al (2020) High absolute lymphocyte counts are associated with longer overall survival in patients with metastatic breast cancer treated with eribulin-but not with treatment of physician's choice-in the EMBRACE study. Breast Cancer 27(4):706\u0026ndash;715\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWatanabe J et al (2020) A maintained absolute lymphocyte count predicts the overall survival benefit from eribulin therapy, including eribulin re-administration, in HER2-negative advanced breast cancer patients: a single-institutional experience. Breast Cancer Res Treat 181(1):211\u0026ndash;220\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eElston CW, Ellis IO (1991) Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up. Histopathology 19(5):403\u0026ndash;410\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAsano Y et al (2016) Predictive Value of Neutrophil/Lymphocyte Ratio for Efficacy of Preoperative Chemotherapy in Triple-Negative Breast Cancer. Ann Surg Oncol 23(4):1104\u0026ndash;1110\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKoyama Y et al (2021) Absolute Lymphocyte Count, Platelet-to-Lymphocyte Ratio, and Overall Survival in Eribulin-treated HER2-negative Metastatic Breast Cancer Patients. Cancer Diagn Progn 1(5):435\u0026ndash;441\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNakamoto S et al (2021) Dynamic Changes in Absolute Lymphocyte Counts During Eribulin Therapy Are Associated With Survival Benefit. Anticancer Res 41(6):3109\u0026ndash;3119\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSu MX et al (2024) Monitoring trends in the absolute lymphocyte count and the neutrophil-to-lymphocyte ratio in patients with breast cancer receiving eribulin. BMC Cancer 24(1):195\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFunahashi Y et al (2014) Eribulin mesylate reduces tumor microenvironment abnormality by vascular remodeling in preclinical human breast cancer models. Cancer Sci 105(10):1334\u0026ndash;1342\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJoyce JA, Fearon DT (2015) T cell exclusion, immune privilege, and the tumor microenvironment. Science 348(6230):74\u0026ndash;80\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhao B, Zhao H (2017) Incidence and risk of eribulin mesylate related hematologic toxicity. Oncotarget\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOhtani S et al (2018) Bi-weekly eribulin therapy for metastatic breast cancer: a multicenter phase II prospective study (JUST-STUDY). Breast Cancer 25(4):438\u0026ndash;446\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 3 are available in the Supplementary Files section.\u003c/p\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":"Breast Cancer, Eribulin, Predictive marker, Absolute lymphocyte count","lastPublishedDoi":"10.21203/rs.3.rs-7341073/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7341073/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eIn the EMBRACE study, eribulin (ERI) monotherapy improved the overall survival (OS) of patients with HER2-negative advanced breast cancer (HER2-ABC). A \u003cem\u003epost hoc\u003c/em\u003e analysis identified the baseline absolute lymphocyte count (ALC) as a predictive marker in the ERI arm. We focused on factors at the termination of treatment that had not been considered previously.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e We retrospectively analyzed 370 patients receiving ERI for HER2-ABC between July 2011 and June 2024 across 3 institutions. Clinical data, including the ALC, neutrophil-to-lymphocyte ratio (NLR), and other factors, were extracted from medical records. Statistical analyses included the log-rank test and Cox hazard model. The OS was defined as the survival from the initiation of ERI (OS1) and from the termination of ERI (OS2).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e In the univariate analysis, the OS1 was longer in patients \u0026gt; 65 years old, ER-positive, and with ALC \u0026gt; 1000/μL at ERI initiation than in others, and the OS2 was longer in ER-positive cases with an ERI time-to-treatment-discontinuation (TTD) \u0026gt; 120 days and ALC \u0026gt; 1000/μL at ERI completion. In the multivariate analysis, ER positivity and baseline ALC \u0026gt; 1000/μL remained associated with a longer OS1. ALC \u0026gt; 1000/μL at ERI completion and an ERI TTD \u0026gt; 120 days remained associated with a longer OS2. In the first-line ERI group, the ALC was maintained during ERI administration, whereas in those who received other treatments, it significantly decreased (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e An ALC \u0026gt; 1000/μL at ERI completion was associated with an improved post-ERI OS. Maintaining the ALC during ERI administration may be associated with a favorable prognosis.\u003c/p\u003e","manuscriptTitle":"Identifying immune-related predictive factors for post-eribulin therapy in patients with HER2-negative advanced breast cancer- A multicenter retrospective study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-11 10:58:29","doi":"10.21203/rs.3.rs-7341073/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":"c48220ff-d01f-49a7-ae5e-70247c325c39","owner":[],"postedDate":"September 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-25T00:53:30+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-11 10:58:29","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7341073","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7341073","identity":"rs-7341073","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}