Breast cancer incidence after hormonal infertility treatment in Sweden: a cohort study
Journal article, 2009
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.
Incidence
Breast Neoplasms/*chemically induced/epidemiology
carcinogenesis
Female
Female/*adverse effects/therapeutic use
Clomiphene/*adverse effects/therapeutic use
Prospective Studies
Female/*drug therapy
Sweden/epidemiology
Infertility
Fertility Agents
ovulation induction
therapy
pregnancy
estrogens
Adult
Humans
Cohort Studies
risk
health
Chorionic Gonadotropin/*adverse effects/therapeutic use
prevention
fertility drugs
postmenopausal women
Author
C Orgeas
Karin Sanner
Per Hall
Peter Conner
Jan Holte
Staffan Nilsson
Karin Sundfeldt
University of Gothenburg
Ingemar Persson
Kee Seng Chia
Sara Wedren
Paul Dickman
Kamilla Czene
American Journal of Obstetrics and Gynecology
0002-9378 (ISSN) 1097-6868 (eISSN)
Vol. 200 1 72 e1-7Subject Categories
MEDICAL AND HEALTH SCIENCES
Obstetrics, Gynecology and Reproductive Medicine
DOI
10.1016/j.ajog.2008.08.066