Serum tumor marker CYFRA 21-1 in the diagnostics of squamous cell lung cancer--comparison with CEA

The aim of the study was to test the diagnostic value of serum tumor marker CYFRA 21-1 for squamous cell lung cancer (SQCLC) in comparison with carcinoembryonic antigen (CEA). Ninety-one patients were included in this study: 56 with SQCLC-Group I, 25 with other types of lung cancer-Group II, 10 with benign respiratory tract diseases-Group III. Median CYFRA 21-1 serum concentration (ng/ml) was: in Group I: 4.52 (0.94 - > 16), in Group II: 3.58 (1.72 - > 16), in Group III: 2.05 (0.99-3.41). Median CEA serum concentration (ng/ml) was: in Group I: 4.49 (0.76 - > 20), in Group II: 3.32 (1.17 - > 20), in Group III: 3.09 (1.84-6.37). There was a highly significant difference between the levels of CYFRA 21-1 in Group I and III (p < 0.001), but there was no statistically significant difference between the levels of CEA in Group I and III. Sensitivity of CYFRA 21-1 by the cut-off 3.33 ng/ml in the diagnostics of SQCLC was 0.68, specificity 0.90, positive predictive value 0.91, negative predictive value 0.65. Sensitivity of CEA by cut-off 4.61 ng/ml was 0.5 by the same specificity 0.90. CYFRA 21-1 has high sensitivity, specificity and positive predictive value in the diagnostics of SQCLC. Sensitivity of CYFRA 21-1 is significantly higher than sensitivity of CEA in this setting.