Epidemiology of vaginal adenosis and adenocarcinoma associated with exposure to stilbestrol in utero.

Following the observation that maternal ingestion of diethylstilbestrol was associated with the development of adenocarcinoma of the vagina in young women, analysis of 170 cases of the disease, collected over a two-year period, was undertaken. Details of history of non-steroidal estrogenic intake during pregnancy, its dosage and duration of intake and prevalence of concomitant abnormalities of the vagina and cervix were recorded. This analysis disclosed that dosage and duration of intake do not appear to be vital factors in contributing to the development of carcinoma. A controlled, prospective investigation of prenatal exposure to stilbestrol was also carried out. Vaginal and cervical abnormalities were common among 110 young women exposed to stilbestrol in utero. Biopsy-proved vaginal adenosis was present in 35% of the exposed population as compared with only 1% of the control subjects. Fibrous ridges of the vagina and cervix and failure of the vaginal mucosa and portions of the cervix to stain with iodine were also more frequently observed in the exposed population. While the risk of developing adenocarcinoma appears to be very low, a majority of exposed females do have other abnormalities of the lower genital tract. While some investigators believe that adenosis is a premalignant lesion, at present there is no clear-cut evidence of transition from adenosis to adenocarcinoma.