{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,4]],"date-time":"2026-10-04T10:50:07Z","timestamp":1791111007037,"version":"4.1.0"},"reference-count":21,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2003,3,3]],"date-time":"2003-03-03T00:00:00Z","timestamp":1046649600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"name":"Swedish Cancer Society"},{"name":"Medical Faculty of Lund University, CTRF, Lund University Hospital"},{"name":"Gunnar Nilsson Foundation"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cancer"],"published-print":{"date-parts":[[2003,3,15]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>BACKGROUND<\/jats:title><jats:p>The authors previously reported an increased risk of breast carcinoma with longer duration of hormone replacement therapy (HRT) use. It is unclear if different types of HRT confer different risks.<\/jats:p><\/jats:sec><jats:sec><jats:title>METHODS<\/jats:title><jats:p>In this study, a population\u2010based cohort of 29,508 women were interviewed during 1990\u20131992 to determine whether there are any differences in breast carcinoma risk according to different types and duration of HRT use.<\/jats:p><\/jats:sec><jats:sec><jats:title>RESULTS<\/jats:title><jats:p>At the end of the follow\u2010up period in December 2001, the cohort constituted 298,649 person\u2010years. Slightly more breast carcinoma cases were seen (<jats:italic>n<\/jats:italic> = 556) than expected (<jats:italic>n<\/jats:italic> = 508.37; standardized morbidity ratio =1.09, 95% confidence interval [CI] = 1.00\u20131.19). Approximately 3663 women had ever used HRT. In Cox regression models, time to breast carcinoma in relation to duration and type of HRT use was analyzed, adjusting for age at menarche, age at first full\u2010term pregnancy, parity, age at menopause, family history of breast carcinoma, and age at interview. In women with a natural menopause, a significantly higher risk was observed for longer duration of combined continuous HRT use compared with never users (hazard ratio [HR] = 4.60, 95% CI = 2.39\u20138.84). Nonsignificant elevated risks also were observed for longer combined sequential (HR = 2.23, 95% CI = 0.90\u20135.56), gestagen only (HR = 3.74,9 5% CI = 0.94\u201314.97), and estriol use (HR = 1.89, 95% CI = 0.81\u20134.39). No increased risk was seen in women after 5 years of nonuse. When studying women who ever used only one type of HRT, even more elevated HRs for gestagen\u2010containing preparations were seen. The highest risks were associated with the combined continuous and gestagen\u2010only therapy in women with \u2265 48 months of use. Use of estradiol without progestins did not increase breast carcinoma risk significantly. The authors estimated the cumulative risk of breast carcinoma in a 50\u2010year\u2010old woman with gestagen\u2010containing therapies for \u2265 48 months, with a follow\u2010up of 10 years, to be 7% (95% CI = 5.4\u201311.4%) compared with 2% (95% CI = 1.6%\u20132.9%) for never\u2010users of HRT.<\/jats:p><\/jats:sec><jats:sec><jats:title>CONCLUSIONS<\/jats:title><jats:p>Longer use of HRT containing progestins significantly elevates breast carcinoma risk whereas estradiol use does not. Continued use of progestins rendered the highest risks. The yearly risk of breast carcinoma for long\u2010term users of progestins is of the magnitude of 50% the risk of a BRCA1 mutation carrier. Cancer 2003;97:1387\u201392. \u00a9 2003 American Cancer Society.<\/jats:p><jats:p>DOI 10.1002\/cncr.11205<\/jats:p><\/jats:sec>","DOI":"10.1002\/cncr.11205","type":"journal-article","created":{"date-parts":[[2003,3,18]],"date-time":"2003-03-18T17:44:31Z","timestamp":1048009471000},"page":"1387-1392","source":"Crossref","is-referenced-by-count":133,"title":["Hormone replacement therapy containing progestins and given continuously increases breast carcinoma risk in Sweden"],"prefix":"10.1002","volume":"97","author":[{"given":"H\u00e5kan L.","family":"Olsson","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christian","family":"Ingvar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Bladstr\u00f6m","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2003,3,3]]},"reference":[{"key":"e_1_2_5_2_2","doi-asserted-by":"crossref","first-page":"1047","DOI":"10.1016\/S0140-6736(97)08233-0","article-title":"Breast cancer and hormone replacement therapy: collaborative re\u2010analysis of data from 49 epidemiological studies involving 51, 977 women with breast cancer and 107, 283 women without breast cancer","volume":"350","author":"Collaborative Group on Hormonal Factors in Breast Cancer","year":"1997","journal-title":"Lancet."},{"key":"e_1_2_5_3_2","doi-asserted-by":"publisher","DOI":"10.1054\/bjoc.2001.1899"},{"key":"e_1_2_5_4_2","doi-asserted-by":"publisher","DOI":"10.1038\/bjc.1986.246"},{"key":"e_1_2_5_5_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.1990.tb02494.x"},{"key":"e_1_2_5_6_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF01806152"},{"key":"e_1_2_5_7_2","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.1998.16.9.3115"},{"key":"e_1_2_5_8_2","doi-asserted-by":"publisher","DOI":"10.1136\/jcp.51.12.935"},{"key":"e_1_2_5_9_2","doi-asserted-by":"publisher","DOI":"10.1093\/oxfordjournals.aje.a115328"},{"key":"e_1_2_5_10_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00051340"},{"key":"e_1_2_5_11_2","doi-asserted-by":"publisher","DOI":"10.7326\/0003-4819-127-11-199712010-00004"},{"key":"e_1_2_5_12_2","doi-asserted-by":"publisher","DOI":"10.1093\/jnci\/91.3.264"},{"key":"e_1_2_5_13_2","doi-asserted-by":"publisher","DOI":"10.1038\/sj.bjc.6690543"},{"key":"e_1_2_5_14_2","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-0215(19990505)81:3<339::AID-IJC5>3.0.CO;2-6"},{"key":"e_1_2_5_15_2","doi-asserted-by":"publisher","DOI":"10.1093\/jnci\/92.4.328"},{"key":"e_1_2_5_16_2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.283.4.485"},{"key":"e_1_2_5_17_2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.288.3.321"},{"key":"e_1_2_5_18_2","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1111\/j.2517-6161.1972.tb00899.x","article-title":"Regression models and life tables","volume":"34","author":"Cox DR","year":"1972","journal-title":"J R Stat Soc [B]."},{"key":"e_1_2_5_19_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0895-4356(97)00004-8"},{"key":"e_1_2_5_20_2","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/16.2.222"},{"key":"e_1_2_5_21_2","doi-asserted-by":"publisher","DOI":"10.1093\/oxfordjournals.aje.a115572"},{"key":"e_1_2_5_22_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199706193362501"}],"container-title":["Cancer"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fcncr.11205","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/acsjournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/cncr.11205","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T13:08:25Z","timestamp":1760274505000},"score":1,"resource":{"primary":{"URL":"https:\/\/acsjournals.onlinelibrary.wiley.com\/doi\/10.1002\/cncr.11205"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2003,3,3]]},"references-count":21,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2003,3,15]]}},"alternative-id":["10.1002\/cncr.11205"],"URL":"https:\/\/doi.org\/10.1002\/cncr.11205","archive":["Portico"],"relation":{},"ISSN":["0008-543X","1097-0142"],"issn-type":[{"value":"0008-543X","type":"print"},{"value":"1097-0142","type":"electronic"}],"subject":[],"published":{"date-parts":[[2003,3,3]]}}}