EVALUATION OF THE SOLUBLE FRAGMENTS OF CYTOKERATIN-19 (CK19) IN NON-SMALL-CELL LUNG-CANCER (NSCLC) - COMPARISON WITH TPA, CEA, SCC AND NSE

This study compared the diagnostic efficacy of serum CK19 determinatio n (Cyfra 21-1) with other tumour markers, such as CEA, SCC, NSE, TPA, in patients with resected non-small lung cancer. Tumour marker levels were tested in 90 patients with benign lung disease and at diagnosis i n 72 patients with proven NSCLC, 39 squamous cell carcinoma and 33 ade nocarcinoma. At presentation baseline levels of all tumor markers were significantly higher (p<0.05) in lung cancer patients than in control subjects, except for NSE. A significant increase (p<0.05) in serum co ncentrations was observed from stage I to stage IIIb only for Cyfra 21 -1 (stage I/II, median=2.7 ng/ml; stage IIIb, median=6.3 ng/ml) and TP A (stage I/II, median=89.8 IU/ml; stage IIIb, median=170.7 IU/ml). Rec eiver operating characteristic (ROC) analysis was performed to evaluat e the best threshold values and the global accuracy of each marker. Th e highest global sensitivity for NSCLC was reached by TPA (70.8%), whe reas that of Cyfra 21-1 was 50%. According to tumour histology, signif icant difference (p<0.05) in serum levels were found only for CEA (ade nocarcinomas, median=5.6 ng/ml; squamous cell carcinoma, median=3.2 ng /ml) and SCC (adenocarcinomas, median=1.0 ng/ml; squamous cell carcino ma, median=1.5 ng/ml). As regards squamous cell carcinoma histotype, t he highest sensitivity was obtained by TPA (74.4% at a specificity of 62.2%) and for adenocarcinomas by CEA (78.8% at a specificity of 85.6% ). Tumour marker levels were also determined during the follow-up of 1 0 patients. The best sensitivity in detecting relapses was shown by CE A (90%), followed by TPA (70%), SCC (50%), Cyfra 21-1 (40%) and NSE (1 0%), even though the CEA test displayed a high percentage of false pos itive results (98.1%) in patients with no evidence of disease (NED).