EVALUATION OF A NEW TUMOR-MARKER FOR CYTOKERATIN-8 AND CYTOKERATIN-18FRAGMENTS IN HEALTHY-INDIVIDUALS AND PROSTATE-CANCER PATIENTS

The serological results from apparently healthy individuals and prosta te cancer patients were evaluated with a new assay called TPAcyk ELISA . This assay has a biochemical specificity for fragments of cytokerati ns 8 and 18, and exhibits a low within- and between-assay imprecision. The data indicate a significant difference between the results of mal es and females, but no significant age-dependent relation was found. T he cut-off value (95% specificity) for healthy individuals was estimat ed to be 1.27 ng/mL (n = 190) for males and 0.95 ng/mL (n = 81) for fe males. When using a cut-off value of 1.27 ng/mL, we found a sensitivit y for prostate cancer patients with T2-3 NOMO of about 20%. For patien ts with metastatic disease, a sensitivity of 75% was found. A higher s ensitivity was obtained with patient sera analyzed with PSA than with TPAcyk, particularly in patients with early stages of the disease. We conclude that the results from this new TPAcyk assay were significantl y elevated in patients initially diagnosed with poorly differentiated tumors, that patients with localized tumors exhibited low concentratio ns, and that patients with metastatic disease showed, on average, 8 ti mes higher concentrations than patients with localized disease. The co mbination of the TPAcyk and PSA results increased the sensitivity for prostate cancer, particularly in patients with metastatic disease. (C) 1994 Wiley-Liss, Inc.