AN EPIDEMIOLOGIC STUDY OF CARCINOMA IN SITU AND SQUAMOUS DYSPLASIA OF THE UTERINE CERVIX1

Abstract

A questionnaire was administered to 324 women with conditions cytologically suggestive of cervical neoplasia and to 302 controls. The cases were 15- to 50-year-old white residents of Washington County, Maryland, who first had an abnormal cytologic smear from 1965 through 1969. Subsequent biopsies revealed that 104 of the cases had carcinoma in situ, 105 had squamous dysplasia, and 25 had only chronic cervicitis; 90 cases were not biopsied. The controls were a probability sample of the population from which the cases were derived. Simultaneous adjustment of 14 variables using multiple linear regression revealed that women with carcinoma in situ differed from the controls by three factors: trichomoniasis, marital instability, and first child conceived before marriage. These results suggest that carcinoma in situ is epidemiologically similar to invasive carcinoma of the cervix as described by others, and that it may result from venereal transmission of one or more carcinogens. Only a portion of the women with dysplasia were epidemiologically similar to those with in situ carcinoma; they tended to have severe dysplasia. Adjustment of 14 variables showed the total group of women with dysplasia to differ from the controls only by the factors trichomoniasis and vaginal discharge. These findings suggest that much dysplasia is a nonspecific reaction of the cervical epithelium to inflammatory agents, and not caused by the same factors as carcinoma in situ.