Dietary factors and the risk of endometrial cancer: a case--control study in Greece

In a hospital-based case-control study of endometrial cancer undertaken in Athens (1992-94), 145 women residents of Greater Athens with confirmed cancer of the endometrium were compared with 298 control patients with orthopaedic diseases. Personal interviews were conducted in the hospital setting, and diet was assessed using a validated semiquantitative food frequency questionnaire. Nutrient intakes for individuals were calculated by multiplying the nutrient intake of a typical portion size for each specified food item by the frequency at which the food was consumed per month and summing these estimates for all food items. Data were modelled through logistic regression, controlling for demographic, reproductive and somatometric risk factors for endometrial cancer as well as for total energy intake. No macronutrient was significantly associated with endometrial cancer risk, but increasing intake of monounsaturated fat, mostly olive oil, by about one standard deviation was associated with a 26% risk reduction (odds ratio = 0.74; 95% confidence interval 0.54-1.3). Among micronutrients, only calcium intake was significantly inversely associated with endometrial cancer risk, whereas there was evidence against retinol and zinc imparting protection against the disease. With respect to food groups, there was weak and non-significant evidence that vegetables are protective, whereas consumption of pulses was positively associated with disease possibly because they contribute substantially in Greece to energy intake in excess of physical activity-dependent requirements.