Br J CancerBritish Journal of Cancer0007-09201532-1827Nature Publishing Group111393272363605669152110.1054/bjoc.2000.1521Regular ArticleLong-term cancer risk in women given diethylstilbestrol (DES) during pregnancyTitus-ErnstoffL1HatchE E2HooverR N2PalmerJ3GreenbergE R14RickerW5KaufmanR6NollerK7HerbstA L8ColtonT9HartgeP3Department of Community and Family Medicine, Dartmouth Medical School and the Norris Cotton Cancer Center, Lebanon, NH 03756Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20892Slone Epidemiology Unit, Boston University School of Public Health, Brookline, MA 02446-4955Department of Medicine, Dartmouth Medical School, Lebanon, NH 03756Information Management Services, Rockville, MD 20852Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX 77030Department of Obstetrics and Gynecology, New England Medical Center, Boston, MA 02111Department of Obstetrics and Gynecology, University of Chicago, Chicago, IL 60637Department of Epidemiology and Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA01012001012001841126133190720002908200030082000Copyright 2001, Cancer Research Campaign2001Cancer Research Campaign

From 1940 through the 1960s, diethylstilbestrol (DES), a synthetic oestrogen, was given to pregnant women to prevent pregnancy complications and losses. Subsequent studies showed increased risks of reproductive tract abnormalities, particularly vaginal adenocarcinoma, in exposed daughters. An increased risk of breast cancer in the DES-exposed mothers was also found in some studies. In this report, we present further follow-up and a combined analysis of two cohorts of women who were exposed to DES during pregnancy. The purpose of our study was to evaluate maternal DES exposure in relation to risk of cancer, particularly tumours with a hormonal aetiology. DES exposure status was determined by a review of medical records of the Mothers Study cohort or clinical trial records of the Dieckmann Study. Poisson regression analyses were used to estimate relative risks (RR) and 95% confidence intervals (CI) for the relationship between DES and cancer occurrence. The study results demonstrated a modest association between DES exposure and breast cancer risk, RR = 1.27 (95% CI = 1.07–1.52). The increased risk was not exacerbated by a family history of breast cancer, or by use of oral contraceptives or hormone replacement therapy. We found no evidence that DES was associated with risk of ovarian, endometrial or other cancer. © 2001 Cancer Research Campaign http://www.bjcancer.com

DESoestrogensbreast cancerendometrial cancerovarian cancercancer