Prostate-specific antigen detection by ultrasensitive assay in samples from women

BACKGROUND The Prostate Specific Antigen (PSA) has been characterized as a specific prostate marker. Recent studies have indicated the existence of a PSA of nonprostatic origin detected in lactating women and breast tumors. METHODS We have evaluated the presence of PSA by an ultransensitive assay (COBAS CORE) in 252 serum and non serum samples from women. RESULTS The results demonstrate the presence of PSA in 100% of the breast secretions, 81% of the breast cysts, 80% of the bronchoalveolar lavage fluids and 71% of the cytosols of breast cancer. Likewise, PSA was detected in 14% of the sera evaluated, although the concentrations were always lower than 0.5 ng/ml. CONCLUSIONS We conclude that PSA should not continue being considered as the specific prostate tissue marker although, given that the serum concentrations detected are very low, they co appear to interfere to a minimum extent in the usefulness of PSA as a tumor marker.