CUTOFF VALUE DETERMINATION OF CYFRA-21-1 FOR SQUAMOUS-CELL CARCINOMASOF THE HEAD AND NECK (SCCHN)

Background. CYFRA 21-1 was found to be a sensitive and specific tumor marker especially for squamous cell carcinomas of the lung. There is n o reliable tumor marker for squamous cell carcinomas of the head and n eck (SCCHN) available. Methods. The amount of Cytokeratin (Ck) 19 in h ealthy tissue and tissues of benign and malignant tumors from pharynx, larynx and lung was compared utilizing a dot-blot assay. CYFRA 21-1 s erum levels were determined prior to therapy in 132 healthy controls, in a reference group consisting of 158 patients with benign diseases o f the head and neck and in 238 patients with a histologically proven S CCHN. Results. Compared to lung tissue Ck 19 levels were similar only in specimen of SCCHN. Ck 19 content in normal and benign tissue from p harynx and larynx was lower than in normal lung tissue. CYFRA 21-1 ser um levels were significantly higher in patients with SCCHN compared to the control or reference group. The cut-off value for CYFRA 21-1 dete rmined at a 95%-specificity of the reference group was found to be 2.2 ng/ml. Conclusions. The Ck 19 level in healthy tissue of the upper ae rodigestive tract was lower than in normal lung tissue. Corresponding to this finding the CYFRA 21-1 serum level in the reference group with benign diseases of the head and neck was lower than that of patients with benign lung diseases. The cut-off level of CYFRA 21-1 for patient s with SCCHN was determined to be 2.2 ng/ml.