Tissue concentrations of tissue polypeptide antigen (TPA) and prostatic specific antigen (PSA) in 42 patients with prostatic carcinoma

BACKGROUND: Following development of methods to quantitate biochemical markers in aspiration biopsies we showed that tissue concentration of prostate specific antigen (T-PSA) decreased with increasing malignancy while serum PSA increased. We also found that T-PSA predicts the clinical outcome better than earlier used prognostic markers. METHODS: In order to further study biochemical markers in prostatic cancer a membrane protein, tissue polypeptide antigen (TPA), which is a complex of polypeptide fragments of cytokeratins 8, 18, and 19, was quantitated in 42 patients with newly diagnosed carcinoma of the prostate. The samples had previously been analyzed for T-PSA. RESULTS: Correlation to TGM classification showed that higher malignancy is correlated to lower tissue TPA values. There is a significant positive correlation (r(s) = 0.49, P < 0.01) between T-TPA and T-PSA. Pretreatment values of T-PSA, but not T-TPA, had association to time to progression or time to death. CONCLUSIONS: Increasing prostatic malignancy is correlated to decreasing values of T-TPA. This indicates that the concentrations of membrane and secretory proteins are changed in the same direction in tissue during cancer development. Tissue TPA seem to have no prognostic value in endocrine treatment of prostatic carcinoma.