Epithelial dysplasia in nipple aspirates of breast fluid: association with family history and other breast cancer risk factors.

Because of the strong association of epithelial dysplasia and breast cancer, the extent to which dysplasia of breast fluid epithelial cells obtained by nipple aspiration is associated with breast cancer risk factors was investigated. A significantly higher proportion of women who had a first-degree family history of breast cancer had dysplastic cells in breast fluid than women who had no such history. When family history status was correlated with various breast cancer risk factors, higher proportions of women with dysplasia were found among those who had a first degree family history of breast cancer and for whom certain other risk factors were present, which suggested additive and synergistic effects of these factors on breast epithelium. Breast epithelia of women with a first-degree family history of breast cancer may be more prone to abnormal differentiation in response to environmentally conditioned risk factors.