INTERACTION OF FAMILY HISTORY OF BREAST-CANCER AND DIETARY ANTIOXIDANTS WITH BREAST-CANCER RISK (NEW-YORK, UNITED-STATES)

We sought to determine if specific dietary antioxidants may be particu larly effective in reducing breast cancer risk for women reporting fam ily history (FH) of breast cancer in a first-degree relative. Intervie ws regarding usual diet, health, and family histories were conducted w ith 262 premenopausal and 371 postmenopausal women with incident, prim ary breast cancer from western New York (United States). These women w ere frequency-matched by age and county of residence with community co ntrols. Among premenopausal women, there was a significant interaction between FH and alpha-tocopherol; alpha-tocopherol was associated with significantly decreased risk among FH+ women (adjusted fourth-quartil e odds ratio [OR] = 0.01, 95 percent confidence interval [CI] = 0.0-0. 3). This association was much weaker for FH-women [OR = 0.7, CI = 0.4- 1.2]. For FH-women, a significant inverse association was observed bet ween beta-carotene and premenopausal breast-cancer risk (OR = 0.4, CI = 0.3-0.5), but not for FH+ women (OR = 0.5, CI = 0.1-4.0). Similar re lationships, although not as strong, were noted among postmenopausal w omen. Although limited by small numbers, these results suggest that bi ologic mechanisms of tumorigenesis may differ in FH+ and FH-women, and that alpha-tocopherol may be a potential chemopreventive agent for wo men with a family history of breast cancer, particularly premenopausal women.