Diet and histologic types of benign breast disease defined by subsequent risk of breast cancer.

The authors investigated the relation between diet and histologic types of benign breast disease defined by subsequent risk of breast cancer in a case-control study of volunteers who entered the Vancouver Center of the Canadian National Breast Screening Study between 1983 and 1985. Proliferative benign breast disease (n = 124) was inversely associated with vitamin A supplementation (vitamin A user vs. nonuser, odds ratio (OR) = 0.5) and frequent green vegetable consumption (frequent vs. rare consumption, OR = 0.3), whereas severe atypias and borderline carcinoma in situ (n = 32) were directly associated with frequent meat fats consumption (frequent vs. rare consumption, OR = 3.2) with no association with vitamin A or vegetable consumption. No dietary relations were found for histologic types of benign breast disease at no increased risk for subsequent breast cancer (n = 274). The implications of these findings in relation to the etiology of breast cancer are discussed.