Cervical Adenocarcinoma and Squamous Cell Carcinoma Incidence Trends among White Women and Black Women in the United States for 1976-2000

BACKGROUND. Although cervical carcinoma incidence and mortality rates have declined in the U.S. greatly since the introduction of the Papanicolaou smear, this decline has not been uniform for all histologic subtypes. Therefore, the authors assessed the differential incidence rates of squamous cell carcinoma (SCC) and adenocarcinoma (AC) of the cervix by race and disease stage for the past 25 years. METHODS. Data from nine population-based cancer registries participating in the U.S. Surveillance, Epidemiology, and End Results (SEER) Program were used to compute incidence rates for cervical carcinoma diagnosed during 1976-2000 by histologic subtype (SCC and AC), race (black and white), age, and disease stage (in situ, localized, regional, or distant). RESULTS. In black women and white women, the overall incidence of invasive SCC declined over time, and the majority of tumors that are detected currently are in situ and localized carcinomas in young women. The incidence of in situ SCC increased sharply in the early 1990s. AC in situ (AIS) incidence rates increased, especially among young women. In black women, invasive AC incidence rose linearly with age. CONCLUSIONS. Changes in screening, endocervical sampling, nomenclature, and improvements in treatment likely explain the increased in situ cervical SCC incidence in white women and black women. Increasing AIS incidence over the past 20 years in white women has not yet translated into a decrease in invasive AC incidence. Etiologic factors may explain the rising invasive cervical AC incidence in young white women; rising cervical AC incidence with age in black women may reflect either lack of effective screening or a differential disease etiology.