Breast cancer incidence after hormonal infertility treatment in Sweden: a cohort study
2009 (English)In: American Journal of Obstetrics and Gynecology, ISSN 0002-9378, Vol. 200, no 1, 72.e1-7 p.Article in journal (Refereed) Published
OBJECTIVE: To assess the impact of infertility treatment with causes of infertility on incidence of breast cancer. STUDY DESIGN: Historical prospective cohort study of 1135 women attending major university clinics for treatment of infertility in Sweden, 1961-1976. Women were classified as users of clomiphene citrate or gonadotropins, or a combination of both therapies. Standardized incidence ratios were calculated to estimate relative risk of breast cancer. RESULTS: We observed 54 cases of breast cancer during 1961-2004, which did not significantly exceed those expected. Users of high-dose clomiphene citrate had an almost 2-fold increased risk (standardized incidence ratio, 1.90; 95% confidence interval, 1.08-3.35). This association was more pronounced among women referred for nonovulatory factors, with 3-fold increased risk (standardized incidence ratio, 3.00; 95% confidence interval, 1.35-6.67). CONCLUSION: No overall increased risk for breast cancer was shown with infertility treatment. Women with nonovulatory causes treated with high-dose clomiphene citrate therapy may have an elevated risk for breast cancer.
Place, publisher, year, edition, pages
2009. Vol. 200, no 1, 72.e1-7 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-107695DOI: 10.1016/j.ajog.2008.08.066ISI: 000262400600020PubMedID: 19121659OAI: oai:DiVA.org:uu-107695DiVA: diva2:232509