Purpose: To analyze trends in invasive cervical cancer incidence by age, histology, and race over a 35-year period (1973-2007) in order to gain insight into changes in the presentation of cervical cancer.
Methods: Data from the nine Surveillance, Epidemiology, and End Results (SEER) registries that continuously collected information on invasive cervical cancer were analyzed for trends. Standardized to the 2000 U.S population, annual age-adjusted incidence rates were estimated by race and histologic subtype. Histologic subtype was classified into squamous, adenocarcinoma, and adenosquamous.
Results: Overall incidence rates for invasive cervical cancer decreased by 54% over the 35 years, from 13.07/100,000 (1973-1975) to 6.01/100,000 (2006-2007), and the incidence rates declined by 51% and 70.2%, respectively, among whites and blacks. The incidence rates for squamous carcinoma decreased by 61.1% from 10.2/100,000 (1973-1975) to 3.97/100,000 (2006-2007). Incidence rates for adenosquamous cell carcinomas decreased by 16% from 0.27/100,000 (1973-1975) to 0.23/100,000 (2006-2007), and incidence rates for adenocarcinomas increased by 32.2% from 1.09/100,000 (1973-1975) to 1.44/100,000 (2006-2007). This increase in adenocarcinomas was due to an increase in incidence in white women; a decrease in incidence was observed for black women.
Conclusions: Although marked reductions in the overall and race-specific incidence rates of invasive cervical cancer have been achieved, they mask important variation by histologic subtype. These findings suggest that alternatives to Pap smear-based screening, such as human papillomavirus (HPV) testing and HPV vaccination, need to be prioritized if adenocarcinomas of the cervix are to be controlled.