EXPOSURE TO BREAST-MILK IN INFANCY AND THE RISK OF BREAST-CANCER

Early childhood nutrition may affect the subsequent risk of breast can cer in adulthood. We examined the association of having been breastfed with risk of breast cancer in a case-control study of women age 40-85 years in western New York. Cases (N = 528) had newly diagnosed primar y, pathologically confirmed breast cancer; controls (N = 602) were ran domly selected from the same community and were frequency matched on a ge. Having been breastfed was associated with decreased risk. The mult ivariate adjusted odds ratio was 0.74, and the 95% confidence interval was 0.56-0.99. We found little difference in the association for pre- and post-menopausal women despite a much higher frequency of breastfe eding among the older women. These findings indicate that early nutrit ure in general and bottle feeding in particular may relate to breast c ancer development in adulthood.