Growth factor profiles in breast cyst fluid identify women with increased breast cancer risk.

Gross cystic disease and breast cancer are hormonally induced diseases that may share a common biochemical environment conducive to abnormal proliferative responses. Breast cyst fluid samples were analyzed for specific growth factors and levels were compared with breast cancer risk. Growth factor profiles identified both women at increased breast cancer risk and subgroups of women with distinct clinical manifestations of gross cystic disease. Women at increased risk for breast cancer demonstrated in their breast cyst fluid lower levels of platelet-derived growth factor and transforming growth factor (TGF)-beta, compared to women at lower risk. The presence of multiple cysts was associated with increased mitogenic activity, increased epidermal growth factor (EGF) and TGF-beta breast cyst fluid levels, and recurrent cysts were associated with higher levels of EGF. Unique growth factor profiles were associated with each risk group or clinical state, suggesting that distinct proliferative environments, associated with different clinical outcomes, are present in the breast tissue of women with gross cystic disease.