{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,29]],"date-time":"2026-03-29T00:04:42Z","timestamp":1774742682485,"version":"3.50.1"},"reference-count":18,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2011,1,7]],"date-time":"2011-01-07T00:00:00Z","timestamp":1294358400000},"content-version":"vor","delay-in-days":5454,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Acta Obstet Gynecol Scand"],"published-print":{"date-parts":[[1996,2]]},"abstract":"<jats:p><jats:italic>Background.<\/jats:italic> The goal of this study is to quantify the risk of breast cancer related to use of oral contraceptives while adjusting for known risk factors, e.g. age at first delivery, number of children, and family history, as well as minimising memory bias.<\/jats:p><jats:p><jats:italic>Methods.<\/jats:italic> A historical prospective study design was used. Data collected over a period of 25 years in the screening program of a cancer detection clinic for women aged 25\u201069 years were utilised. Information on breast cancer among those attending the screening program was searched for in the national cancer registry. Women with breast cancer were matched on date of birth with on average 5.3 control women who were still alive when the diagnosis was made. Mothers and sisters of cases and controls were identified through a national genealogy registry.<\/jats:p><jats:p><jats:italic>Results.<\/jats:italic> The odds ratio of developing breast cancer among women with a first degree relative with breast cancer was about 2, but for those ever using oral contraceptives it was 0.92 and even lower (0.50\u20100.75) if the cancer was diagnosed before the age of 45 years.<\/jats:p><jats:p><jats:italic>Conclusions.<\/jats:italic> Use of oral contraceptives (OC) does not seem to increase the risk of developing breast cancer among women in Iceland.<\/jats:p>","DOI":"10.3109\/00016349609033309","type":"journal-article","created":{"date-parts":[[2007,11,22]],"date-time":"2007-11-22T00:48:11Z","timestamp":1195692491000},"page":"157-161","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Oral contraceptives and risk of breast cancer"],"prefix":"10.1111","volume":"75","author":[{"given":"Helgi","family":"T\u00f3masson","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kristinn","family":"T\u00f3masson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2011,1,7]]},"reference":[{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(94)92826-6"},{"issue":"8645","key":"e_1_2_1_3_1","first-page":"973","article-title":"Oral contraceptive use and breast cancer risk in young women","volume":"1","author":"Chilvers C.","year":"1989","journal-title":"Lancet"},{"key":"e_1_2_1_4_1","doi-asserted-by":"publisher","DOI":"10.1093\/oxfordjournals.aje.a115132"},{"key":"e_1_2_1_5_1","first-page":"374","article-title":"Oral contraceptives and breast cancer. Cause and effect?","volume":"36","author":"Harlap S.","year":"1991","journal-title":"J Reprod Med"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0002-9378(12)90938-2"},{"key":"e_1_2_1_7_1","doi-asserted-by":"publisher","DOI":"10.1093\/jnci\/81.13.1000"},{"key":"e_1_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/ijc.2910460305"},{"key":"e_1_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.1038\/bjc.1993.387"},{"key":"e_1_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/ijc.2910130513"},{"key":"e_1_2_1_11_1","first-page":"62","volume-title":"Record Linkage in Medicine","author":"Bjarnason O.","year":"1968"},{"key":"e_1_2_1_12_1","unstructured":"Heilbrig is og tryggingam\u00e1lar\u00e1 uneyti (Department of Health and Social Security in Iceland). Skj\u00f6l 1967\u20131992 (Archives 1967\u20131992) Reykjavik."},{"key":"e_1_2_1_13_1","doi-asserted-by":"publisher","DOI":"10.1002\/ijc.2910460604"},{"key":"e_1_2_1_14_1","first-page":"22","article-title":"Working Party: Breast\u2010cancer etiology","volume":"5","author":"Nordic Cancer Union (NCU)","year":"1990","journal-title":"Int J Cancer"},{"key":"e_1_2_1_15_1","first-page":"25","volume-title":"Applied logistic regression","author":"Hosmer D. W.","year":"1989"},{"key":"e_1_2_1_16_1","first-page":"248","volume-title":"The analysis of case control studies","author":"Breslow N. 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