{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,15]],"date-time":"2025-12-15T20:00:23Z","timestamp":1765828823622,"version":"3.48.0"},"reference-count":38,"publisher":"BMJ","issue":"1","license":[{"start":{"date-parts":[[2021,1,30]],"date-time":"2021-01-30T00:00:00Z","timestamp":1611964800000},"content-version":"unspecified","delay-in-days":29,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2021,1,13]]},"published-print":{"date-parts":[[2021,1]]},"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>Being either young or old at the time of breast cancer diagnosis has been suggested as an indicator of a poor prognosis. We studied the effect of age at breast cancer onset in relation to survival, focusing in particular on biological subtypes and reproductive anamnesis.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design, setting and participants<\/jats:title>\n                    <jats:p>Patients with early breast cancer (n=594) treated in a Finnish University Hospital during 2003\u20132013 were prospectively collected and followed in median 102 months.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Patients with luminal A-like breast cancer were older than the patients with luminal B-like (HER2-positive) (p=0.045) or patients with the HER2-positive (non-luminal) subtype (p=0.029). Patients \u226570 years received substantially less adjuvant chemotherapy (p=1.5\u00d710\n                      <jats:sup>\u22129<\/jats:sup>\n                      ) and radiotherapy (p=5.9\u00d710\n                      <jats:sup>\u22127<\/jats:sup>\n                      ) than younger women. Nevertheless, the estimated 10-year breast cancer-specific rates of survival were 84.2%, 92.9% and 87.0% in age groups &lt;41 years, 41\u201369 years and \u226570 years, respectively, with no statistical difference (p=0.115). Survival rates were also comparable between the three age groups when assessed separately in different biological subtypes, and for patients with metastatic breast cancer there was similarly no difference between the age groups. Later menarche (p=5.7\u00d710\n                      <jats:sup>\u22128<\/jats:sup>\n                      ) and high parity (p=0.000078) correlated with increased age at breast cancer diagnosis, but, according to the patients\u2019 oestrogen receptor (ER) status, only among ER-positive patients.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Despite the suggested undertreatment of older patients, we report excellent long-term outcomes in all age groups in this prospective cohort. Later endogenous endocrine exposure may cause delay in breast cancer onset, but the exact biology behind this phenomenon is so far unclear.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2020-041706","type":"journal-article","created":{"date-parts":[[2021,1,31]],"date-time":"2021-01-31T06:05:18Z","timestamp":1612073118000},"page":"e041706","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":3,"title":["Real-world, single-centre prospective data of age at breast cancer onset: focus on survival and reproductive history"],"prefix":"10.1136","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3490-3702","authenticated-orcid":false,"given":"Peeter","family":"Karihtala","sequence":"first","affiliation":[{"name":"Department of Oncology, Helsinki University Hospital Comprehensive Cancer Centre, University of Helsinki, Helsinki, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anniina","family":"J\u00e4\u00e4skel\u00e4inen","sequence":"additional","affiliation":[{"name":"Department of Oncology and Radiotherapy, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nelli","family":"Roininen","sequence":"additional","affiliation":[{"name":"Department of Oncology and Radiotherapy, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arja","family":"Jukkola","sequence":"additional","affiliation":[{"name":"Department of Oncology and Radiotherapy, Faculty of Medicine and Health Technology, Tampere University Hospital, Tampere University, Tampere, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2021,1,31]]},"reference":[{"key":"2025121511560621000_11.1.e041706.1","doi-asserted-by":"publisher","DOI":"10.3322\/caac.21590"},{"key":"2025121511560621000_11.1.e041706.2","doi-asserted-by":"publisher","DOI":"10.1016\/S1470-2045(12)70425-4"},{"key":"2025121511560621000_11.1.e041706.3","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1038\/bjc.1981.168","article-title":"Morphological evaluation of cell turnover in relation to the menstrual cycle in the \"resting\" human breast","volume":"44","author":"Ferguson","year":"1981","journal-title":"Br J Cancer"},{"key":"2025121511560621000_11.1.e041706.4","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0007695"},{"key":"2025121511560621000_11.1.e041706.5","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.2007.14.2471"},{"key":"2025121511560621000_11.1.e041706.6","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pmed.0030025"},{"key":"2025121511560621000_11.1.e041706.7","doi-asserted-by":"publisher","DOI":"10.1038\/35021093"},{"key":"2025121511560621000_11.1.e041706.8","doi-asserted-by":"crossref","first-page":"v8","DOI":"10.1093\/annonc\/mdv298","article-title":"Primary breast cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow-up","volume":"26 Suppl 5","author":"Senkus","year":"2015","journal-title":"Ann Oncol"},{"key":"2025121511560621000_11.1.e041706.9","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.2015.65.8013"},{"key":"2025121511560621000_11.1.e041706.10","doi-asserted-by":"crossref","first-page":"689","DOI":"10.1007\/s10549-018-4950-4","article-title":"Young age at diagnosis is associated with worse prognosis in the luminal a breast cancer subtype: a retrospective institutional cohort study","volume":"172","author":"Liu","year":"2018","journal-title":"Breast Cancer Res Treat"},{"key":"2025121511560621000_11.1.e041706.11","unstructured":"Brierley J , Gospodarowicz MK . 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