Diet patterns and the risk of renal cell carcinoma

Objectives: Our objective was to identify food intake patterns that might be associated with the risk of renal cell carcinoma. Design: A total of 461 cases (210 females, 251 males) were age frequency matched to population controls. Diet factors were created using factor analysis of 69 food items from a food-frequency questionnaire. These factors were modelled using logistic regression to identify those associated with renal cell carcinoma. Setting: We investigated the role of diet in the aetiology of renal cell carcinoma using a population-based case-control study conducted in Ontario between 1995 and 1996. Subjects: Cases were Ontario residents 20 to 74 years of age identified through review of pathology reports in the Ontario Cancer Registry. Results: A 'dessert' diet factor was positively associated with disease for both sexes (odds ratio estimate (OR) for males = 3.7, 95% confidence interval (CI) 2.0-6.9; OR for females = 1.4, 95% CI 0.8-2.2, for the highest vs. lowest quartile). In males, a 'beef' diet factor was identified and was associated with an increased risk of renal cell carcinoma. Furthermore, a 'juices' diet factor also showed an association with increased risk in males (OR = 1.8, 95% CI 1.0-3.1). For females, a positive association was observed between renal cell carcinoma and an 'unhealthy' diet factor (OR = 1.4, 95% CI 0.8-2.4). Conclusions: Our findings confirmed that high-fat and high-protein diets might be risk factors for renal cell carcinoma. The data also suggest an increased risk associated with juice intake, a finding not previously reported.