{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T23:50:40Z","timestamp":1777679440263,"version":"3.51.4"},"reference-count":28,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T00:00:00Z","timestamp":1775001600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Tamoxifen is a cornerstone of endocrine therapy for hormone receptor-positive breast cancer. While its common side effects are well-documented, severe hematological toxicities such as neutropenia and leukopenia are extremely rare.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Case presentation<\/jats:title>\n                    <jats:p>We report a case of a 37-year-old premenopausal woman with hormone receptor-positive breast cancer who developed neutropenia and leukopenia three months after initiating adjuvant tamoxifen (20 mg\/day). Despite transient improvements with supportive therapies (leucogen tablets and Compound Ejiao Jiang), cytopenias persisted. Tamoxifen was discontinued and switched to ovarian function suppression (leuprolide) plus an aromatase inhibitor (exemestane). Within four weeks, neutrophil and leukocyte counts normalized and remained stable over six months of follow-up.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>This case highlights the importance of recognizing tamoxifen-induced hematological toxicity. Regular blood count monitoring is essential, and in premenopausal women intolerant to tamoxifen, switching to ovarian function suppression plus an aromatase inhibitor is a safe and effective alternative.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fonc.2026.1691480","type":"journal-article","created":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T04:25:10Z","timestamp":1775017510000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Tamoxifen-induced neutropenia and leukopenia in a breast cancer patient: a case report and literature review"],"prefix":"10.3389","volume":"16","author":[{"given":"Cheng","family":"Liu","sequence":"first","affiliation":[{"name":"Department of Breast Surgery, Liaocheng Maternity and Child Health Care Hospital","place":["Liaocheng, Shandong, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fadong","family":"Xu","sequence":"additional","affiliation":[{"name":"Department of Breast Surgery, Liaocheng Maternity and Child Health Care Hospital","place":["Liaocheng, Shandong, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qinglai","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Breast Surgery, Liaocheng Maternity and Child Health Care Hospital","place":["Liaocheng, Shandong, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,4,1]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(11)60993-8","article-title":"Relevance of breast cancer hormone receptors and other factors to the efficacy of adjuvant tamoxifen: patient-level meta-analysis of randomised trials","volume":"378","author":"Davies","year":"2011","journal-title":"Lancet"},{"key":"B2","doi-asserted-by":"publisher","first-page":"392","DOI":"10.1016\/j.pharmthera.2013.05.005","article-title":"Toxicity and adverse effects of Tamoxifen and other anti-estrogen drugs","volume":"139","author":"Yang","year":"2013","journal-title":"Pharmacol Ther"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.22.01065","article-title":"Adjuvant endocrine therapy in premenopausal breast cancer: 12-year results from SOFT","volume":"41","author":"Francis","year":"2023","journal-title":"J Clin Oncol"},{"key":"B4","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.critrevonc.2007.01.005","article-title":"Contribution of modelling chemotherapy induced hematological toxicity for clinical practice","volume":"63","author":"Testart-Paillet","year":"2007","journal-title":"Crit Rev Oncol Hematol"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1080\/14740338.2017.1376645","article-title":"Non-chemotherapy drug-induced neutropenia - an update","volume":"16","author":"Andr\u00e8s","year":"2017","journal-title":"Expert Opin Drug Saf"},{"key":"B6","first-page":"39","article-title":"Toxicity and side-effects of combination chemohormonal therapy of advanced breast cancer","volume":"90","author":"Mohapatro","year":"1992","journal-title":"J Indian Med Assoc"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(94)91929-1","article-title":"Fatal neutropenia associated with long-term tamoxifen therapy","volume":"344","author":"Mik\u00e9","year":"1994","journal-title":"Lancet"},{"key":"B8","doi-asserted-by":"publisher","first-page":"1220","DOI":"10.1259\/0007-1285-58-696-1220","article-title":"Myelosuppression occurring after receiving tamoxifen for breast cancer. 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