{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T22:42:35Z","timestamp":1792622555446,"version":"4.5.0"},"reference-count":25,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T00:00:00Z","timestamp":1792627200000},"content-version":"vor","delay-in-days":113,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["npj Breast Cancer"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    Postpartum breast cancer (PPBC) is associated with worse outcomes in young women with breast cancer and demonstrates distinct transcriptomic features, yet a temporal definition based on gene expression has not been established. We conducted a single-institution retrospective cohort study to evaluate the impact of postpartum status on the 21-gene Oncotype DX Recurrence Score\u00ae (RS) in hormone receptor-positive, HER2-negative young women with breast cancer. Among 385 patients, 153 were nulliparous, 62 were more than 10 years postpartum, and 170 were within 10 years postpartum. Diagnosis within one year of childbirth was associated with a 13.2-point higher RS compared with nulliparous patients (\n                    <jats:italic>p<\/jats:italic>\n                    \u2009&lt;\u20090.001). Defining PPBC as within 3 years postpartum was associated with increased odds of RS category shift (OR 2.83,\n                    <jats:italic>p<\/jats:italic>\n                    \u2009=\u20090.001). In the context of contemporary adjuvant treatment, with patients diagnosed within three years postpartum more likely to receive chemotherapy, ovarian function suppression, and CDK4\/6 inhibitors, differences in IDFS associated with time since last childbirth did not result in significantly worse IDFS within the follow-up period (89.0% in patients with PPBC up to 3 years vs. 93.7% in all other patients\n                    <jats:italic>p<\/jats:italic>\n                    \u2009=\u20090.39). These findings indicate that tumors diagnosed within the first year postpartum have significantly elevated RS, and that the period of most aggressive PPBC, as reflected by gene expression profiles, may arise in the more recently postpartum period, in the first 0\u20133 years postpartum.\n                  <\/jats:p>","DOI":"10.1038\/s41523-026-01002-2","type":"journal-article","created":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T07:33:11Z","timestamp":1782891191000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Identifying the window of aggressive postpartum breast cancer based on the 21-gene Oncotype DX\u00ae test in women with HR+, HER2-negative breast cancer"],"prefix":"10.1038","volume":"12","author":[{"given":"Shiliang","family":"Zhang","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katelyn J.","family":"Queen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Niharika","family":"Duggirala","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric","family":"Yang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marla","family":"Lipsyc-Sharf","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer","family":"Racz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John","family":"Bennett","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaden","family":"Hong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yashila","family":"Suresh","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Charlotte","family":"Hamilton","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Meghana","family":"Pitta","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicole","family":"Chien","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emily","family":"La","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christy A.","family":"Russell","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aditya","family":"Bardia","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nimmi S.","family":"Kapoor","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,7,1]]},"reference":[{"key":"1002_CR1","doi-asserted-by":"publisher","first-page":"286","DOI":"10.1186\/s12905-024-03138-4","volume":"24","author":"AP Londero","year":"2024","unstructured":"Londero, A. 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Cancers 16, 1555 (2024).","journal-title":"Cancers"}],"container-title":["npj Breast Cancer"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41523-026-01002-2","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41523-026-01002-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41523-026-01002-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T22:27:06Z","timestamp":1792621626000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41523-026-01002-2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,1]]},"references-count":25,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,12]]}},"alternative-id":["1002"],"URL":"https:\/\/doi.org\/10.1038\/s41523-026-01002-2","relation":{},"ISSN":["2374-4677"],"issn-type":[{"value":"2374-4677","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,1]]},"assertion":[{"value":"5 March 2026","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"20 June 2026","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"1 July 2026","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"J.R., J.B., and C.R. are employees of Abbott. M.L.S. reports personal fees from Natera, Exact Sciences, Guardant Health, Eli Lilly, Novartis, Stemline Therapeutics, and TerSera Therapeutics, including service on an advisory board for Novartis, outside the submitted work. N.K. reports consulting fees from IceCure Medical, Inc., Aura Health Technologies, and Elucent Medical, and grant funding from BTX\/Hologic, outside the submitted work. A.B. reports grants and personal fees from Pfizer, Novartis, Merck, Genentech, AstraZeneca\/Daiichi, Alyssum, Menarini, Gilead, and Eli Lilly, outside the submitted work. The other authors declare no competing financial or non-financial interests.","order":1,"name":"Ethics","label":"Competing interests","group":{"name":"EthicsHeading","label":"Ethics"}}],"article-number":"139"}}