The Incidence of Cervical Cancer and Duration of Oral Contraceptive Use

In a prospective study carried out on a cohort of 17,942 women belonging to the Kaiser Foundation Health Plan and living in suburban communities of the San Francisco Bay Area, a positive association was found between the incidence of cervical carcinoma and total duration of oral contraceptive use. The association was established while controlling for the effects of age, education, and selected infections. The association persists when incident cases of dysplasia are added to those of carcinoma. A further study, in which covariates relating to sexual behavior will also be taken into account, is in progress.