Effects of lifestyle and diet as modifiers of risk of breast cancer (BC) in BRCA1 and BRCA2 carriers.

1505 Background: Mutations in the BRCA1/2 genes confer a high lifetime risk of BC. Penetrance varies among populations and individuals suggesting that non-genetic factors may modify the inherited risk. Knowledge of modifiable factors will help to develop preventive strategies. Methods: Information on physical activity (PA) (current PA and in the adolescence) and smoking was collected in 892 women (W) with a BRCA1/BRCA2 germ-line mutation (582 with BC, 45,62% BRCA2) from 279 families, followed at three Spanish Genetic Counseling Units, 481of these W also answered a food frequency questionnaire. Participants gave their consent and the study was approved by the ethics committee. The associati…