Serum tumor marker CYFRA 21-1 in the diagnostics of NSCLC lung cancer.

Cytokeratins are epithelial markers whose expression is not lost during malignant transformation. The level of soluble cytokeratin fragment 19 was measured with an enzyme immunoassay method developed by Boehringer Mannheim (Enzymum-test CYFRA 21-1) in the serum of 200 male and 50 female patients with NSCLC (Non Small Cell Lung Cancer) lung cancer (120 planocellulare and 80 adenocarcinoma in males; 22 planocellulare and 28 adenocarcinoma in females). The comparative group comprised 50 young healthy males and 50 females without any clinical proof for malignancy or any other lung disease. The aim of this investigation was to find out if any possible statistical difference exists in the serum level of CYFRA 21-1 between patients with lung cancer and healthy controls, and also between different types of lung cancers. The mean value of serum CYFRA 21-1 in NSCLC (6.25 ng/ml) was significantly higher than in healthy controls (1.26 ng/ml) (p < 0.001). Sensitivity for CYFRA 21-1 (using 3.3 ng/ml, a cut-off value corresponding to a 98% specificity for healthy controls) in NSCLC was 60.5%. Positive CYFRA 21-1 levels were significantly higher in patient with carcinoma planocellulare (66.2%) than in adenocarcinoma (52.1%). CYFRA 21-1 levels were significantly different between squamous cell carcinoma (6.52 ng/ml) and adenocarcinoma (5.86 ng/ml) (p < 0.05). Our results indicate that CYFRA 21-1 may be a useful tumor marker in NSCLC, especially in carcinoma planocellulare. CYFRA 21-1 may also be useful in identification of the preoperative stages of diseases and the postoperative monitoring of NSCLC.