Physical activity and renal cell carcinoma among black and white Americans: a case-control study

BACKGROUND: Renal cell carcinoma (RCC) has a higher incidence in blacks than in whites. Physical activity may influence the risk of renal cell cancer, but the evidence is inconsistent. No previous study has investigated this relationship in the black population. METHODS: We examined the association between self-reported physical activity at different ages and risk of RCC in a population based case-control study of 1217 cases (361 black, 856 white) and 1235 controls (523 black, 712 white) frequency-matched on age, race, and gender. Multivariate-adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression. RESULTS: Among whites, increased risks of RCC were observed among participants reporting low levels of transportation-related activity in their 20’s (OR (<1 hr/wk vs >7 hr/wk) (95% CI): 1.42 (1.10, 1.83)) and leisure time activity in their 50’s (OR (<1 hr/wk vs >7 hr/wk) (95% CI): 1.49 (1.00, 2.20)). We found no association between physical activity and RCC risk among blacks. CONCLUSION: Our results suggest that physical activity may be inversely associated with RCC risk in whites, but there was no evidence of such an association in blacks. As this is the first study evaluating the effect of physical activity on RCC risk among blacks, further investigations are needed to clarify the relationship in this population. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2407-14-707) contains supplementary material, which is available to authorized users.