Race/ethnicity and advanced stage of renal cell carcinoma in adults: results from surveillance, epidemiology, and end results program 2007-2015.

Non-Hispanic Blacks were shown to have an earlier stage of renal cell carcinoma (RCC) at diagnosis compared to non-Hispanic Whites. It is less clear whether disparities in RCC staging occurs for other minority races/ethnicities. We aimed to assess the association between racial/ethnic minorities and stage at diagnosis of RCC, and test for potential effect modification by histological subtype. Sourced from the Surveillance, Epidemiology and End Results (SEER) database, patients ≥20 years diagnosed with RCC from 2007 to 2015 were included (n = 37 493). Logistic regression analyses were performed to assess the independent association between race/ethnicity [non-Hispanic White, non-Hispanic Black, non-Hispanic Asian Pacific Islander, non-Hispanic American Indian/Alaskan Native (AI/AN) and Hispanic] and advanced RCC stage at diagnosis (i.e. regional spread or distant metastasis). Interaction terms were tested and stratified regression was performed accordingly. Twenty-eight percent of patients had advanced RCC stage at diagnosis. After adjusting for age, gender, year of diagnosis, histological subtype and insurance status, compared to non-Hispanic Whites, non-Hispanic Blacks had lower odds of advanced stage at diagnosis [odds ratio (OR) = 0.79; 95% confidence interval (CI) = 0.72-0.87 for clear cell; OR = 0.48; CI = 0.30-0.78 for chromophobe and OR = 0.26; CI = 0.10-0.35 for other subtypes]. Higher odds of advanced stage at diagnosis were found for non-Hispanic AI/AN in clear cell (OR = 1.27; CI = 1.04-1.55) and for Hispanics in papillary subtypes (OR = 1.58; CI = 1.07-2.33). Racial disparities in the RCC stage at diagnosis varied according to histological subtype. Further investigation on the racial disparities reported is warranted to optimize detection and ultimately improve the prognosis of patients with RCC.