Background: CYFRA 21-1 was found to be a sensitive and specific tumor marker especially for squamous cell carcinomas of the lung. There is no reliable tumor marker for squamous cell carcinomas of the head and neck (SCCHN) available.
Methods: The amount of Cytokeratin (Ck) 19 in healthy tissue and tissues of benign and malignant tumors from pharynx, larynx and lung was compared utilizing a dot-blot assay. CYFRA 21-1 serum levels were determined prior to therapy in 132 healthy controls, in a reference group consisting of 158 patients with benign diseases of the head and neck and in 238 patients with a histologically proven SCCHN.
Results: Compared to lung tissue Ck 19 levels were similar only in specimen of SCCHN. Ck 19 content in normal and benign tissue from pharynx and larynx was lower than in normal lung tissue. CYFRA 21-1 serum levels were significantly higher in patients with SCCHN compared to the control or reference group. The cut-off value for CYFRA 21-1 determined 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 aerodigestive 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 patients with SCCHN was determined to be 2.2 ng/ml.