Cerumen phenotype and epithelial dysplasia in nipple aspirates of breast fluid.

The relationship between presence of dysplastic epithelial cells in nipple aspirates of breast fluid and wet or dry cerumen phenotype was studied in 1,150 white and Asian American women. A statistically significant greater proportion of premenopausal white women of wet cerumen phenotype, compared to women of the dry cerumen type, was found to have cytologic dysplasia (relative risk 6.5 [1.8--22.3]). The effect was not observed in postmenopausal women. The finding offers new support for our hypothesis that an apocrine genetic factor affecting breast gland secretion may influence exposure of the breast epithelium to potential carcinogenic substances of exogenous or endogenous origin.