Alcohol consumption and risk of benign proliferative epithelial disorders of the breast in women.

Many studies have shown a positive association between alcohol consumption and risk of breast cancer. Benign proliferative epithelial disorders (BPED) of the breast are conditions which, although not proven precursors of breast cancer, are strongly associated with increased risk of this disease. The association between alcohol consumption and risk of BPED was examined in a case-control study conducted in Adelaide, South Australia. The study involved 383 cases with biopsy-confirmed BPED, 192 controls whose biopsy did not show epithelial proliferation, and 383 unbiopsied community controls individually matched (I:I) to cases on age and area of residence. When cases were compared with community controls, the unadjusted relative risk of BPED for drinkers versus non-drinkers was 0.9 (95% CI 0.6-1.3), and the corresponding relative risk derived from comparing cases with biopsy controls was 1.0 (95% CI 0.6-1.4); these estimates were not altered after adjustment for potential confounding. Variation in risk of BPED across levels defined in terms of daily total alcohol intake, and in terms of daily alcohol intake from individual beverages, was mostly insubstantial and not dose-dependent. Also, there was little variation in risk with age at first drink, or by current drinking status, and risk of BPED in association with alcohol consumption did not increase with severity of cytologic atypia. Despite the absence of an association in this study, further investigation is warranted, since it may provide opportunities for the prevention of BPED and of breast cancer.