Abstract
PURPOSE: Accumulating evidence suggests an etiologic role in renal cell carcinoma (RCC) for physical activity. However, it is unknown if prolonged sitting, which is thought to be distinct from too little moderate-vigorous physical activity, is an independent risk factor for RCC. The authors prospectively examined the relationship of prolonged sitting and risk of RCC among 289,512 women and men in the National Institutes of Health-AARP Diet and Health Study. METHODS: From 1996 through 2006, 1206 invasive RCC cancer cases were identified. Cox proportional hazards regression was used to estimate multivariate hazard ratios (HR) and 95% confidence intervals. RESULTS: After controlling for known risk factors for RCC, we did not find evidence of associations between RCC risk and time spent per day sitting while watching television or videos (HR(7 + hrs: < 1 hr) = 0.96 (0.66, 1.38); p trend = 0.707) or total sitting time (HR(9 + hrs: < 3 hrs) = 1.11 (0.87, 1.41); p trend = 0.765). CONCLUSIONS: Prolonged sitting time was not associated with RCC risk among men and women in this large cohort.