Increased Frequency of Adenocarcinoma of the Uterine Cervix in Young Women in Los Angeles County2

Abstract

By hypothesizing that oral contraceptives (OC's) might have a carcinogenic effect on glandular cells of the cervix if given during periods of active metaplasia (e.g., postmenarchal adolescence), an increasing rate of cervical adenocarcinorna was predicted in young women who had been teenagers when OC's were introduced roughly 20 years ago. Secular trends for cervical carcinomas in non-Hispanic whites were examined by age, histologic type, and social class by using data from the Los Angeles County population-based tumor registry. Between 1972 and 1982, the frequency of invasive cervical adenocarcinoma in women under 35 years of age increased from about 2 to about 5 annually, amounting to an average rate of change of 8% per year (P<.01). There was essentially no trend for women over 35 years old; the frequency of other invasive carcinomas (and of squamous carcinoma in situ) decreased at average rates of about 3% per year in wcmen under 35 years of age and decreased more rapidly in older women. The increase in adenocarcinoma, unlike risk from cervical cancer generally, was most striking among young women residing in middle-to-upper income neighborhoods, who were the first to use OC's; in this subgroup the average rate of increase was 16% per year (P<.05). These findings are compatible with our hypothesis and merit further study.