Abstract A75: Preexisting kidney disorders and risk of renal cell carcinoma: Results from a population-based case-control study of Caucasians and African Americans

Abstract

Abstract Background: In the United States, the incidence of renal cell carcinoma (RCC) is higher among African Americans (AA) than among Caucasians. However, few studies have investigated potential risk factors that may contribute to racial disparities in RCC incidence. Established risk factors for RCC include smoking, obesity, and hypertension. Beyond these factors the etiology of RCC remains largely unknown, though previous observations suggest that patients with end-stage renal disease on long-term dialysis may be at increased risk of developing RCC. Methods: We conducted an investigation of RCC risk in relation to pre-existing kidney disorders in a population-based case-control study of AAs and Caucasians in the metropolitan regions of Chicago and Detroit. Personal interviews were conducted to obtain information on history of kidney disorders and other covariates from 1,217 RCC cases (361 AAs and 856 Caucasians) and 1,235 controls (523 AAs and 712 Caucasians). Odds ratios (OR) and 95% confidence intervals (CI) were estimated using sample weighted unconditional logistic regression models adjusted for age, sex, race, level of education, smoking status, body mass index, history of hypertension, family history of cancer, and study center. Analyses stratified by race and time since kidney disease diagnosis were also performed. Results: A statistically significant increased risk of RCC was observed among subjects who had been previously diagnosed with chronic renal failure (OR 4.7, 95% CI 2.2–10.1) or were on dialysis (OR 18.0, 95% CI 3.6–91.1). Stronger associations were observed among subjects who had renal failure or were on dialysis 10 or more years prior to RCC diagnosis. The association between chronic renal failure and RCC was considerably stronger among AAs than among Caucasians (ORs of 8.7 and 2.0, respectively; P-interaction=0.03). Among AAs, history of kidney stones, kidney cysts, and nephrotic syndrome were all associated with an elevated risk of RCC (OR≥2.0), though these findings were not statistically significant. Conclusions: The results of this large population-based study suggest that chronic renal failure and dialysis may be important risk factors for RCC development in both AAs and Caucasians. Our findings of differences in risk estimates by race, to our knowledge the first such report, require replication. Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):A75.