Rates and Risks of Diethylstilbestrol-Related Clear-Cell Adenocarcinoma of the Vagina and Cervix

Abstract

We reviewed 519 cases of clear-cell adenocarcinoma of the vagina and cervix identified by the Registry for Research on Hormonal Transplacental Carcinogenesis of the University of Chicago through June 30, 1985. In 60 percent of all cases the patient's mother had received diethylstilbestrol during pregnancy. An additional 12 percent of all mothers had been treated with another hormone or with an unidentified medication. Ninety-one percent of the cases in diethylstilbestrol-exposed women were diagnosed when the patient was between the ages of 15 and 27. The median age at diagnosis was 19.0 years. The risk that clear-cell adenocarcinoma will develop in an exposed female from birth through age 34 is 1 case per 1000 women. The temporal pattern of occurrence of clear-cell adenocarcinoma corresponds closely with that of the use of diethylstilbestrol for pregnancy support in the United States. The rarity of this tumor among exposed women suggests that diethylstilbestrol is not a complete carcinogen and that some other factor is also involved in the pathogenesis of clear-cell adenocarcinoma of the vagina and cervix.

Cancer risk in women prenatally exposed to diethylstilbestrol

“…Our estimate of absolute risk of 1.6/1,000 by age 39 is remarkably similar to previous estimates based on indirect measures. 16 We also previously reported an agerelated increased breast cancer risk associated with DES exposure. At this point in follow-up, there is no convincing evidence of any other excess cancer risks except for these 2 sites.…”

Abnormal Cervical Appearance: What to Do, When to Worry?

“…The relative risk of CCA in a DES daughter is 40.7 as compared with that of a nonexposed woman. 20 About 1 to 1.5 in 1000 DES daughters will develop CCA with a peak incident in their late teens to early twenties; however, it has been reported in women in their thirties and forties. 21,22 Because most non-DES-related CCA occurs after menopause and most DES daughters are currently entering menopause, it is unclear whether an increase in CCA in this age group of DES daughters will be seen.…”

The effect of phytoestrogens on the female genital tract

“…One in 1000 women exposed to diethylstilboestrol in utero will develop the disease. 82 Such exposure is iatrogenic, has been discussed elsewhere, 83 84 and given that it is not our aim in this review to discuss the effects of iatrogenically administered oestrogens, falls outside the scope of this review. The remainder of the literature explores the effects of environmental oestrogens on fertility and the oestrous cycle.…”