Cervical cancer occurrence in Memphis and Shelby County, Tennessee, during 25 years of its cervical cytology screening program.

This review of the cytologic history of 430 women with histologically proved invasive cancer of the uterine cervix indicates that several significant subgroups can be defined. One major subgroup consists of 142 patients or 33% of the total group in whom invasive cancer developed within 1 to 5 years, with an average of 2.6 years, after one or more negative cytologic findings. This appears to be a significant proportion of the occurrence of invasive cervical cancer and warrants consideration in the recommendation of screening intervals. The second major subgroup, consisting of 88 patients (20.5%), had a delay in diagnosis averaging 9.9 years after the first abnormal cytologic finding. In some of these patients either the cytologic examination results reverted to negative for a period or the biopsy material did not confirm the cytologic abnormalities. The disease progressed to invasion. These findings appear to bear out the importance of close follow-up of patients with any abnormal cytologic finding in the intraepithelial neoplasia category even though intermittent cytologic studies may appear negative.