Prostate-specific antigen (PSA) in women.

Prostate-specific antigen (PSA) is a valuable tumor marker for prostate cancer. It was believed that PSA was produced exclusively by the epithelial cells of the prostate gland, but a large body of evidence demonstrates that PSA is not a prostate-specific molecule. PSA has been shown to be expressed in many forms of female tissues. The breast is a major female organ able to produce PSA. PSA is detected in both normal and abnormal breast tissues, as well as in various breast fluids including milk, nipple aspirate, and cyst fluid. Androgens and progesterones, via their receptors, regulate the production of PSA in breast tissue. Clinical studies demonstrate that PSA in breast cancer is associated with the expression of estrogen receptor and progesterone receptor. Women with PSA-positive breast cancer have better disease-free survival as well as overall survival than those with PSA-negative breast cancer. PSA levels in nipple aspirate fluid may be indicative of breast cancer risk. High concentrations of PSA are found in amniotic fluid and the levels change with gestational age. Pregnant women have elevated serum PSA. PSA levels in serum also vary during menstrual cycles and increase in women with excess androgen. Clinical implications of PSA in amniotic fluid and female serum have been suggested. More studies are needed to further explore their utilities.