Cytokeratin markers in patients with prostatic diseases

Recently tissue polypeptide specific antigen (TPS), a cytokeratin 18 marker, was described to be discriminative between cancer of the prostate (CaP) and benign prostatic hyperplasia (BPH). Cyfra 8/18, a marker which recognizes both cytokeratin 8 and 18 fragments, is thought to improve sensitivity and specificity of TPS. In our study we investigated the ability of the TPS and cyfra 8/18 serum concentration to discriminate between patients with clinically localized CaP and BPH.

Serum levels of TPS and Cyfra 8/18 were determined in patients with untreated CaP (pT1-3pNoMo: n = 11) and BPH (n = 22). The TPS and the Cyfra 8/18 concentrations were correlated to the prostate specific antigen (PSA) serum concentration.

Median TPS concentration was 45.3 U/L in CaP-patients and 54.8 U/L in BPH-patients. This difference is statistically not significant (p = 0.2). Median Cyfra 8/18 level was 0.64 ng/mL in CaP-patients and 0.57 ng/mL in BPH-patients. This difference is statistically not significant (p = 0.91). Furthermore no correlation with PSA levels could be established (TPS: r = -0.13; Cyfra 8/18: r = 0.17).

In contrast to recent reports we found both cytokeratin markers, TPS as well as Cyfra 8/18, to be non-discriminative parameters in CaP and BPH.