Time trends in the incidence of cervical and other genital squamous cell carcinomas and adenocarcinomas in Sweden, 1958-1996

Abstract

Objectives: We wanted to examine reasons for the different incidence trends for cervical squamous cell carcinoma (SCC, declining) and adenocarcinoma (increasing).

Methods: The Swedish Family-Cancer Database on 9.6 million individuals was used to derive incidence trends between 1958 and 1996. Cervical cancers were compared to vaginal and vulvar cancers.

Results: A total of 15405 invasive cervical SCCs and 1920 adenocarcinomas were identified. The incidence of SCCs decreased and that of adenocarcinoma increased during the study period, with similar trends among the in situ forms. The incidence of in situ vaginal and vulvar SCC increase 22-fold, whereas, invasive SCC and adenocarcinoma remained unchanged. The age-incidence curves for adenocarcinoma resembled those for SCC before screening, suggesting similar clinical course.

Conclusions: The data suggest that the increase in the incidence of adenocarcinoma is related to an increasing prevalence of human papilloma virus (HPV) infection in female genitals, perhaps in addition to other factors. The increase is not seen in SCC because of effective screening.