Racial disparity in incidence patterns and outcome of kidney cancer

To identify the subgroups that primarily contribute to the greater incidence and mortality of renal cancer in black Americans compared with white Americans.

We analyzed age, stage, and race-related differences in the incidence and survival among patients with renal cancer using the national Surveillance, Epidemiology, and End Results (SEER) registry database. White and black patients with renal cell carcinoma who were older than 19 years of age and had been diagnosed between 1975 and 1998 were included. Incidence trends were analyzed by joinpoint regression with the statistical significance level at P <0.05. The Cox proportional hazards model was used to determine the overall survival of patients with renal cell carcinoma by race (white versus black), age (20 to 59 versus 60+ years), and stage (local versus regional/distant).

Localized disease predominantly accounted for the rise in incidence. Both black age groups with localized disease had a greater estimated annual percentage of incidence increase (4.46% for 20 to 59 years and 4.35% for 60+ years) compared with their white counterparts (2.87% and 3.06%, respectively). The magnitude of survival difference was largest between black versus white patients younger than 60 years of age who had local stage disease, with a median survival time of 190 and 259 months, respectively (P <0.0001).

Young black patients with localized renal cancer appear to have had a greater rise in incidence and a poorer outcome than white patients of the same age and disease stage. Additional investigation is warranted to define the role of these race, stage, and age-related disparities in the etiology, prognosis, treatment, and follow-up of kidney cancer.