Dietary patterns associated with colon and rectal cancer: results from the Dietary Patterns and Cancer (DIETSCAN) Project

BACKGROUND: An analysis of dietary patterns or combinations of foods may provide insight regarding the influence of diet on the risk of colon and rectal cancer. OBJECTIVE: A primary aim of the Dietary Patterns and Cancer (DIETSCAN) Project was to develop and apply a common methodologic approach to study dietary patterns and cancer in 4 European cohorts: the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (Finland-ATBC), the Netherlands Cohort Study (NLCS) on Diet and Cancer, the Swedish Mammography Cohort (SMC), and the Ormoni e Dieta nella Eziologia dei Tumori (Italy-ORDET). Three cohorts (ATBC, NLCS, and SMC) provided data on colon and rectal cancer for the present study. DESIGN: The cohorts were established between 1985 and 1992; follow-up data were obtained from national cancer registries. The participants completed validated semiquantitative food-frequency questionnaires at baseline. RESULTS: Exploratory factor analysis, conducted within each cohort, identified 3-5 stable dietary patterns. Two dietary patterns-Vegetables and Pork, Processed Meats, Potatoes (PPP)-were common across all cohorts. After adjustment for potential confounders, PPP was associated with an increased risk of colon cancer in the SMC women (quintile 4(multivariate) relative risk: 1.62; 95% CI: 1.12, 2.34; P for trend = 0.01). PPP was also associated with an increased risk of rectal cancer in the ATBC men (quintile 4(multivariate) relative risk: 2.21; 95% CI: 1.07, 4.57; P for trend = 0.05). Neither pattern was associated with the risk of colon or rectal cancer in the NLCS women and men. CONCLUSION: Although certain dietary patterns may be consistent across European countries, associations between these dietary patterns and the risk of colon and rectal cancer are not conclusive