Physical activity during adulthood and adolescence in relation to renal cell cancer

3093 Background: Evidence for a relationship between physical activity and renal cell cancer has been inconsistent.
 Methods: We examined physical activity in relation to renal cell cancer in a cohort of 499,437 participants (297,926 men and 201,511 women) aged 50-71 at study baseline from the National Institutes of Health-AARP Diet and Health Study. At baseline (1995-1996), participants completed a questionnaire inquiring about current frequency of exercise/ sports activities of at least 20 minutes duration, intensity of daily routine activity, and frequency of activity during adolescence (between ages 15 and 18). Cox regression was used to estimate relative risks (RR) and 95% confidence intervals (95% CI). During up to 8.2 years of follow-up, 1,267 cases were ascertained (945 in men and 322 in women).
 Results: In multivariate models adjusted for renal cell cancer risk factors (i.e. gender, age, race, smoking, BMI, height, history of diabetes, history of hypertension, and protein intake) we observed that current exercise/ sports, routine physical activity, and activity during adolescence were associated with a reduced risk of renal cell cancer. The multivariate RRs of the highest activity level as compared with the lowest activity level were 0.76 (95% CI: 0.63, 0.91, P trend =0.08) for exercise/ sports, 0.85 (95% CI: 0.58, 1.23, P trend =0.02) for routine physical activity, and 0.82 (95% CI: 0.68, 0.99, P trend =0.03) for activity during adolescence. Assuming a causal relationship, our data suggest that 10% of renal cell cancers would be prevented if all persons exercised three or more times per week for 20 or more minutes and engaged in light or moderate routine activities, as recommended by public health guidelines.
 Conclusion: Increased physical activity, including activity during adolescence, is associated with reduced risk of renal cell cancer.