CYFRA21-1 as a tumor marker in patients with malignant head and neck tumor

It is well known that cytokeratin 19 is particularly abundant in squamous cell carcinoma of the lung. CYFRA21-1 was developed to detect soluble cytokeratin 19 fragment in serum using two specific monoclonal antibodies. We investigated the usefulness of this new marker compared with that of carcinoembryonic antigen (CEA), and squamous cell carcinoma antigen (SCC) using 52 serum samples from patients with head and neck malignancies. Of 50 cases of head and neck carcinomas, CYFRA21-1 was positive (>2.0ng/ml) in 21 cases (42.0%) while SCC was found in 9 cases and CEA in 8 cases. Therefore CYFRA21-1 was proven to be a more useful tumor marker than SCC or CEA. We analyzed the results statistically, and found that age and site of lesion (larynx) were factors affecting CYFRA21-1 concentration. The serum CYFRA21-1 level was also demonstrated to be independent of the other two markers. However, we could not determine the cut-off level of serum CYFRA21-1.