MASS SCREENING OF THE TOTAL FEMALE POPULATION OF A COUNTY FOR CERVICAL CARCINOMA

• Cytological examinations were carried out on smears obtained directly from the endocervical canal with the aid of a speculum or less directly by using a special cancer detection tampon. The 17,761 women so studied by 27,894 smears represented practically the entire female population over the age of 19 years in the county. Cancer cells were found in the specimens of 117 patients; biopsy material was obtained from 84 of these. Carcinoma in situ was found in 56 women (2 of whom were 19 years of age) and invasive carcinoma was found in 28. The average age of women with carcinoma in situ was 39; that for carcinoma in situ with early invasion, 41.6; and that for frankly invasive cancer, 47.8. For the total white female population the prevalence rate of cervical carcinoma in situ was 2.8 per 1,000 and for invasive cancer 1.4 per 1,000. To determine the true incidence rate for cervical carcinoma in situ, repeat examinations were carried out over a period of four years on women known not to have had a cervical lesion at the time of the first examination. The data for incidence indicated that, in every 1,000 women, 1.8 new cases of cervical carcinoma in situ developed each year. There was reason to believe that the figures for prevalence and incidence obtained in this county would be valid for the United States as a whole.