Dietary patterns and the risk of renal cell carcinoma

grantor: University of TorontoWe investigated the role of diet in the etiology of renal cell carcinoma using a population-based case-control study conducted in Ontario between 1995 and 1996. A total of 461 histopathologically confirmed cases (210 females, 251 males) were frequency-matched to controls on (1) age (422 females, 250 males) and (2) age and smoking (217 females, 241 males). For each analysis, diet patterns were created using a factor analysis of 69 food items consumed weekly. These patterns were entered in a stepwise logistic regression analysis to identify patterns most significantly associated with the risk of renal cell carcinoma. For the age-matched analyses, a 'dessert' diet pattern was significantly associated with disease, with the strongest associations observed among men (males, odds ratio estimate (OR) = 3.8, 95% confidence interval (CI) 2.1-7.1; females OR = 1.4, 95% CI 0.8-2.2 for the highest vs. lowest quartile). In the age/smoking-matched analysis, a 'high protein and fat' diet pattern was significantly associated with risk of disease, again with higher risks confined to males (males, OR = 2.7, 95% CI 1.5-4.9; females OR = 1.5, 95% CI 0.8-2.6). With the exception of the age-matched female analysis, the remaining analyses showed a significant increased risk associated with higher consumption levels of a 'fruit juice' pattern (age/smoking-matched males OR = 2.2, 95% CI 1.3-3.8; females OR = 1.4, 95% CI 0.7-2.6). A subsequent analysis of supplementary vitamin C did not reveal any association with renal cell carcinoma. Our findings confirm that high fat and protein diet patterns may be risk factors for renal cell carcinoma. These data also suggest an increased risk is associated with a juice pattern, a finding not previously reported.M.Sc