25-Year Trends in Stage-Specific Incidence Rates for Bladder Cancer in a Large Statewide Registry

Abstract

BACKGROUND: Bladder cancer (BC) is a common genitourinary malignancy with over 80,000 new cases diagnosed annually and over 17,000 associated deaths. OBJECTIVE: We review 25-years of BC incidence (1993-2017) within the state of Pennsylvania to better define incidence, geographic distribution, and trends over time. METHODS: The Pennsylvania Cancer Registry was reviewed for statewide and component county age-adjusted BC incidence rates and stage distribution. Chloropleth maps plotting statewide and county-specific incidence rates across time were created using the GeoDa statistical package. RESULTS: 93,476 cases of BC were recorded in Pennsylvania from 1993 to 2017. Age-adjusted annual rates of BC over the study interval were stable at 24.5 patients per 100,000 (range, 22.7–25.6). However, annual rates of distant disease increased from 0.5 to 1.1 patients per 100,000 (p < 0.001) with an average percent change increase of 6.6% over the study interval. The annual percent distribution of distant disease doubled from 2.3% to 5.1% (p < 0.001) with a greater increase in women compared to men. Chloropleth maps highlighted growing “hot spots” of bladder cancer incidence in the northwestern, northeastern, and southeastern portions of the state. CONCLUSIONS: While BC incidence in the state of Pennsylvania has remained relatively stable over the past 25 years, a concerning increase in distant disease was observed. Geospatial investigation implicates higher risk regions. Further studies are necessary to delineate the underlying etiologies for these observations.