Prostate-specific antigen in breast disease.

The aim of this study is to assess tissue and serum prostate-specific antigen (PSA) in breast lesions; to compare tissue PSA with serum PSA; to compare tissue PSA in benign and malignant lesions and to compare PSA with known prognostic factors in breast carcinoma. Tissue PSA immunoreactivity in twenty women with breast carcinoma was compared with PSA in twenty-three women with benign breast lesions. Tissue PSA was also compared with known prognostic indicators such as tumour size, axillary nodal status, histological type, histological grade, oestrogen receptor status, progesterone receptor status and c-erbB-2 oncoprotein over-expression. Serum free PSAlevels from these women were measured pre- and post-operatively and an attempt was made to correlate serum PSA with tissue PSA expression. 40% and 43% of malignant and benign breast lesions respectively showed tissue PSA immunoreactivity. No significant difference was observed in the tissue PSA expression between these two groups as also between tissue PSA and known prognostic indicators. As serum PSA levels were below the detection limit (< 0.004 ng/ml) in all except two benign cases, no statistical evaluation was done for the latter. Tissue PSA expression did not correlate with other prognostic markers and detectable serum PSA levels were present in too few cases for statistical analysis. Although no definitive conclusion is possible in this preliminary study regarding the role of PSA in breast disease, it stimulates interest in further research in this direction.