{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T09:22:35Z","timestamp":1777454555631,"version":"3.51.4"},"reference-count":17,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2025,12,1]],"date-time":"2025-12-01T00:00:00Z","timestamp":1764547200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2025,12,1]],"date-time":"2025-12-01T00:00:00Z","timestamp":1764547200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Breast Cancer&amp;#65533;(Auckl)"],"published-print":{"date-parts":[[2025,12]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>\n                      Although\n                      <jats:italic toggle=\"yes\">BRCA1<\/jats:italic>\n                      and\n                      <jats:italic toggle=\"yes\">BRCA2<\/jats:italic>\n                      mutations are known to be associated with different breast cancer (BC) subtypes, real-world evidence on how these genetic differences influence tumor behavior and treatment decisions remains limited, particularly in Japanese patients. With the recent expansion of PARP inhibitor indications in Japan,\n                      <jats:italic toggle=\"yes\">BRCA<\/jats:italic>\n                      testing has become increasingly routine, highlighting the need for clinical data tailored to local populations.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objectives:<\/jats:title>\n                    <jats:p>\n                      To compare clinicopathological features, recurrence patterns, and surgical choices between\n                      <jats:italic toggle=\"yes\">BRCA1<\/jats:italic>\n                      - and\n                      <jats:italic toggle=\"yes\">BRCA2<\/jats:italic>\n                      -associated BC in Japanese patients, with a focus on ER-positive tumors.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design:<\/jats:title>\n                    <jats:p>A single-institution retrospective cohort study.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>\n                      We retrospectively reviewed 417 patients who underwent\n                      <jats:italic toggle=\"yes\">BRCA1\/2<\/jats:italic>\n                      genetic testing at a single Japanese institution between April 2020 and November 2023. Of these, 38 patients (12\n                      <jats:italic toggle=\"yes\">BRCA1<\/jats:italic>\n                      , 26\n                      <jats:italic toggle=\"yes\">BRCA2<\/jats:italic>\n                      ) had pathogenic variants. We compared clinicopathological features, recurrence patterns, and choices of risk-reducing surgery between\n                      <jats:italic toggle=\"yes\">BRCA1<\/jats:italic>\n                      and\n                      <jats:italic toggle=\"yes\">BRCA2<\/jats:italic>\n                      carriers.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>\n                      <jats:italic toggle=\"yes\">BRCA1<\/jats:italic>\n                      -associated cancers were predominantly triple-negative (75%) and diagnosed at earlier stages (T1 in 83.3%), while\n                      <jats:italic toggle=\"yes\">BRCA2<\/jats:italic>\n                      -associated cancers were mainly ER-positive (69.2%) and more likely to present with multiple lymph node metastases (\u2a7e2 nodes in 42.3%). Although Ki-67 levels were higher in\n                      <jats:italic toggle=\"yes\">BRCA1<\/jats:italic>\n                      tumors, this was largely subtype-dependent. Notably, ER-positive\n                      <jats:italic toggle=\"yes\">BRCA<\/jats:italic>\n                      tumors showed a trend toward higher recurrence. Preferences for prophylactic surgery also varied by mutation type.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion:<\/jats:title>\n                    <jats:p>\n                      This single-institution study highlights clinically meaningful differences between\n                      <jats:italic toggle=\"yes\">BRCA1<\/jats:italic>\n                      - and\n                      <jats:italic toggle=\"yes\">BRCA2<\/jats:italic>\n                      -associated BC in Japanese patients.\n                      <jats:italic toggle=\"yes\">BRCA2<\/jats:italic>\n                      cancers tended to present with more advanced features, while\n                      <jats:italic toggle=\"yes\">BRCA1<\/jats:italic>\n                      cancers were more often detected at earlier stage. These findings underscore the value of\n                      <jats:italic toggle=\"yes\">BRCA<\/jats:italic>\n                      testing not only for PARP inhibitor eligibility but also for subtype-specific risk assessment and individualized preventive strategies.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/11782234251399355","type":"journal-article","created":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T05:51:53Z","timestamp":1765605113000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["Clinical and Pathological Characteristics and Treatment Implications of\n                    <i>BRCA1<\/i>\n                    - and\n                    <i>BRCA2<\/i>\n                    -Mutated Breast Cancer in Japanese Patients: A Single-Institution Retrospective Study"],"prefix":"10.1177","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-7333-5448","authenticated-orcid":false,"given":"Yumiko","family":"Akita","sequence":"first","affiliation":[{"name":"Department of Breast and Endocrine Surgery, Nagoya University Hospital, Nagoya, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4423-4023","authenticated-orcid":false,"given":"Madoka","family":"Iwase","sequence":"additional","affiliation":[{"name":"Department of Breast and Endocrine Surgery, Nagoya University Hospital, Nagoya, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Toyone","family":"Kikumori","sequence":"additional","affiliation":[{"name":"Department of Breast and Endocrine Surgery, Nagoya University Hospital, Nagoya, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dai","family":"Takeuchi","sequence":"additional","affiliation":[{"name":"Department of Breast and Endocrine Surgery, Nagoya University Hospital, Nagoya, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuko","family":"Takano","sequence":"additional","affiliation":[{"name":"Department of Breast and Endocrine Surgery, Nagoya University Hospital, Nagoya, Japan"},{"name":"Department of Clinical Oncology and Chemotherapy, Nagoya University Hospital, Nagoya, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takahiro","family":"Ichikawa","sequence":"additional","affiliation":[{"name":"Department of Breast and Endocrine Surgery, Nagoya University Hospital, Nagoya, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7302-0278","authenticated-orcid":false,"given":"Norikazu","family":"Masuda","sequence":"additional","affiliation":[{"name":"Department of Breast and Endocrine Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan"},{"name":"Department of Breast Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2025,12,12]]},"reference":[{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1706450"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa2105215"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.breast.2006.12.003"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1038\/modpathol.3800453"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.2008.16.6231"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.2006.09.1066"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.2017.7112"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1177\/1758835920975326"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1001\/jamaoncol.2022.0476"},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1038\/s10038-017-0355-1"},{"key":"e_1_3_3_12_2","doi-asserted-by":"publisher","DOI":"10.7326\/0003-4819-147-8-200710160-00010"},{"key":"e_1_3_3_13_2","doi-asserted-by":"publisher","DOI":"10.1038\/s10038-020-00849-y"},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1177\/1359105317697812"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1038\/415530a"},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMra1001389"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.3390\/cancers11060738"},{"key":"e_1_3_3_18_2","first-page":"1187","article-title":"Risk-reducing mastectomy for women with hereditary breast and ovarian cancer (HBOC): analytical results of data from the Japanese organization of HBOC","volume":"52","author":"Ohsumi S","year":"2022","unstructured":"Ohsumi S, Nakamura S, Miyata H, et al. Risk-reducing mastectomy for women with hereditary breast and ovarian cancer (HBOC): analytical results of data from the Japanese organization of HBOC. Jpn J Clin Oncol. 2022;52:1187-1193.","journal-title":"Jpn J Clin Oncol"}],"container-title":["Breast Cancer: Basic and Clinical Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/11782234251399355","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/11782234251399355","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/11782234251399355","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T12:56:50Z","timestamp":1777381010000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/11782234251399355"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12]]},"references-count":17,"alternative-id":["10.1177\/11782234251399355"],"URL":"https:\/\/doi.org\/10.1177\/11782234251399355","relation":{},"ISSN":["1178-2234","1178-2234"],"issn-type":[{"value":"1178-2234","type":"print"},{"value":"1178-2234","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12]]},"article-number":"11782234251399355"}}