Dietary fat and risk of renal cell carcinoma in the USA.: a case-control study

B65

An increased risk of renal cell carcinoma (RCC) has bee n linked with obesity. However, there is limited information about the contribution of a high fat diet to RCC risk. A population-based case-control study of 406 cases and 2,434 controls aged 40 to 85 years was conducted in Iowa in 1986-89. For 323 cases and 1820 controls from this study, information on dietary intake from foods high in fat nutrients and other lifestyle factors had been obtained using a mailed questionnaire. Cancer risks were estimated by odds ratios (OR) and 95% confidence intervals (CI), taking into account other known risk factors, especially obesity, hypertension, and smoking habits. Fat intake, measured either by nutrient: total fat (OR=2.4; CI=1.6-3.7, p_trend <0.001) orfood group: high-fat spreads (OR=1.9; CI=1.3-2.7, p_trend <0.001), was associated with an elevated risk of RCC, when the top quartile of dietary fat intake was compared to the bottom quartile. Although total fat, saturated fat, animal fat, retinol and cholesterol were associated with increased RCC risk, vegetable fat and linoleic acid (polyunsaturated fat) were not. Neither dietary protein, carbohydrate, nor total food-calorie consumption, adjusted for fat intake, was related to cancer risk. These findings have implications for dietary, clinical and public health interventions.