Race and renal cell carcinoma stage at diagnosis: An analysis of the Surveillance, Epidemiology, and End Results data

To study racial differences in tumor stage at diagnosis among Black and White patients with renal cell carcinoma (RCC) by histologic type and time period. The patients were Black and White patients with RCC from 1999 to 2011 derived from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. Multinomial logistic regression was used to assess the associations between cancer stage and race and then stratified by histology and diagnosis year. Compared to Whites, Blacks were less likely to be diagnosed with regional disease [odds ratio (OR)=0.67; 95% confidence interval (CI)=0.60-0.73] or distant disease (OR=0.82; 95% CI=0.74-0.90) after adjusting for age, sex, year of diagnosis, and tumor grade. When stratified by RCC histology, similar results were observed for clear cell (OR=0.71; 95% CI=0.63-0.80), chromophobe (OR=0.51; 95% CI=0.32-0.81), and other histologic type (OR=0.63; 95% CI=0.42-0.96) while the association was not significant for papillary histology. The analyses by time showed a lower likelihood to have regional disease in Black than White in 2003-2006 (OR=0.66; 95% CI=0.55-0.79) and 2007-2011 (OR=0.57; 95% CI=0.49-0.67). Black patients were also less likely to have distant disease in 2007-2011 period (OR=0.76; 95% CI=0.65-0.88). In conclusion, blacks were less likely to be diagnosed at a later stage RCC than Whites regardless of cancer histology. This racial disparity may exist over time during the study period.