Circulating fragments of cytokeratin 19 in patients with head and neck squamous cell carcinoma.

In head and neck squamous cell carcinoma a reliable serum marker of carcinogenesis should be of predictive value for the development of recurrent disease or a second primary tumour. At the moment, such a tumour marker is not available. Recently, elevated levels of cytokeratin 19-fragments (Cyfra 21-1) have been detected in the serum of patients with lung cancer, in particular with squamous cell carcinoma. Cytokeratin 19 is an intermediate cell filament protein expressed in simple epithelia and their malignant counterparts. Therefore, in this prospective study, a standardized sandwich enzyme-linked immunosorbent assay for soluble cytokeratin 19 fragments was tested in the serum of 20 patients with a previously untreated head and neck squamous cell carcinoma. The results were compared with that of 20 control individuals. Our results showed significantly higher Cyfra 21-1 concentrations in the serum of patients with cancer (10.21 +/- 3.03 ng/ml) than the controls (7.2 +/- 2.63 ng/ml). After radical treatment the marker levels dropped significantly to 1.65 +/- 1.07 ng/ml. Cyfra 21-1 appears to be of value as a circulating tumour marker for head and neck squamous cell carcinoma especially in monitoring disease control.