Within-state Geographical Variations in Renal Cell Carcinoma Incidence: Rural Disparities in the State of Illinois

Abstract

Objectives: Rural-urban disparities in renal cell carcinoma (RCC) mortality have been observed, and we sought to determine if increased male RCC incidence rates in six contiguous counties (S6Co) in rural southern Illinois (IL) could be explained by known risk factors or require consideration of other etiological influences. Methods: We analyzed incidence and behavioral risk factor data for the S6Co, similarly rural IL and US counties (rural-urban classification codes 7 through 9; ILRUCC 7-9 and USRUCC 7-9), the remaining IL counties (ILr), and total IL and US. Results: ILRCC rates are higher than the US at both the total population (22.2/100,000 (95% CI=21.8-22.6) vs. 19.9 (19.8-20.1)) and rural (RUCC7-9; 23.7 (21.7-25.8) vs. 20.7 (19.9-21.5)) levels, with S6Co the highest (30.8 (24.8-37.5)). Within IL, the S6Co RCC rate remained significantly increased compared to both IL r and IL RUCC 7-9 after adjustment for smoking, obesity and hypertension. Conclusion: Rural IL males experience increased RCC risk which may be attributed to a locally-specific combination of genetic, environmental and cultural factors. State-level chronic disease control programs should examine how such factors may significantly vary across relatively small geographical scales.