Case-control study of dietary patterns and endometrial cancer risk.

Dietary patterns, rather than intakes of specific foods or nutrients, may influence risk of endometrial cancer (EC). This population-based case-control study in Canada (2002-2006) included incident EC cases (n = 506) from the Alberta Cancer Registry and controls frequency age-matched to cases (n = 981). Past-year dietary patterns were defined using factor analysis of food frequency questionnaire data. Logistic regression was used to estimate EC risk within quartiles of dietary patterns. Three patterns (sweets, meat, plants) explained 23% of the variance in the dietary data. In multivariable models, EC risk was significantly reduced by 30% for women in the highest quartile of the healthier plants pattern (OR = 0.70, 95% CI 0.50-0.98, P trend = 0.02). When stratified by body mass index (BMI; kg/m(2)), risk was further reduced among overweight or obese women with a BMI ≥25 (OR = 0.57, 95% CI 0.39-0.83; P trend = 0.004). EC was not associated with the less healthy sweets and meat patterns. However, risk was modestly, but not significantly, elevated for higher intakes of the meat pattern among overweight or obese women. A mostly plant-based dietary pattern may reduce EC risk. Recommendations for risk reduction should focus on maintaining a healthy weight and the role of diet should be studied further.