EVALUATION OF A NEW TUMOR-MARKER IN PATIENTS WITH NON-SMALL-CELL LUNG-CANCER - CYFRA-21.1

The Cyfra 21.1 assay is a newly developed test which measures in serum a fragment of cytokeratin 19. We evaluated this marker in 212 patient s with non-small-cell lung cancer (NSCLC), predominantly stage 3a-b an d 4, and compared it with three other markers: carcinoembryonic antige n (CEA), squamous cell carcinoma antigen (SCC) and tissue polypeptide antigen (TPA). Sensitivities for Cyfra 21.1, TPA, CEA and SCC (using c ut-off levels corresponding to a 95% specificity for benign lung disea ses) were 40%, 40%, 42% and 19% respectively. The sensitivity of CEA w as significantly higher in patients with adenocarcinomas compared with the other three markers, while the sensitivity of Cyfra 21.1 and TPA was significantly higher in patients with squamous cell carcinomas. Th e value of Cyfra 21.1 for monitoring disease during chemotherapy could be evaluated in 23 patients with squamous cell carcinomas. When the c ases of lead time were included a concordance between clinical evaluat ions according to WHO response criteria and evaluations according to c hanges in the marker levels of 74% was found. The criteria defined for marker response were a 65% decrease in the marker level for a partial response and a 40% increase for progressive disease. In particular, i ncreasing levels of this marker indicated usually disease progression. In conclusion, Cyfra 21.1 is a useful serum marker for patients with NSCLC, especially for disease monitoring of patients with squamous cel l carcinoma during and after chemotherapy.