Cancer Risk Among Women Exposed to Exogenous Estrogens During Pregnancy2

Abstract

A cohort of 3,139 obstetric patients, who delivered children between 1946 and 1965, was followed retrospectively to assess the relationship between exposure to diethylstilbestrol [(DES) CAS: 56-53-1; α,α′-diethyl-4,4′-stilbenediol] or other estrogenic substances during pregnancy and subsequent cancer incidence. Among the 1,531 women exposed to DES, the relative risk (RR) for all cancers was 1.46 [95% confidence interval (Cl), 1.07–2.00]. The RR for cancers of the breast, cervix, and ovary were 1.37 (adjusted), 1.40, and 2.83, respectively, but none of these estimates was statistically significant. For breast cancer an RR in excess of 2.28 can be excluded, with 95% Cl for doses averaging 2,100 mg. Within the exposed group there was no evidence for a dose-response relationship.

2

Supported by Public Health Service (PHS) grant CA-20347 from the Division of Extramural Activities, National Cancer Institute (NCI); by PHS grant N01CP-61002 from the Division of Cancer Cause and Prevention, NCI; by grant PDT144 from the American Cancer Society; and by the Institute of Occupational Medicine and Hygiene, Yale University School of Medicine.

Author notes

3

Connecticut Cancer Epidemiology Unit and Department of Epidemiology and Public Health, Vale University School of Medicine, New Haven, Conn. 06510.

5

Merrill Lynch Inc., 195 Church St., New Haven, Conn. 06510.

6

Connecticut Tumor Registry, Hartford, Conn. 06106.

7

We thank Dalia Laub, Susan Fekety, William Mangine, and Gregory Morgan for their valuable help with the data collection and management.