Serum level of cytokeratin 19 fragment (CYFRA 21-1) indicates tumour stageand prognosis of squamous cell carcinoma of the oesophagus

To determine the clinical efficacy of serum concentration of cytokeratin 19 fragment (CYFRA 21-1), sera from 66 patients with oesophageal squamous cel l carcinoma were examined, and 54 surgically resected specimens were immuno histochemically stained for cytokeratin 19 (CK-19), The patients with posit ive CK-19 staining in the tissues of their carcinomas had significantly hig her serum CYFRA 21-1 levels compared with those with negative CK-19 stainin g, When the cut-off value was defined as 2.0 ng/mL, CYFRA 21-1 had a higher positive ratio than that of either squamous cell carcinoma antigen (SCC-Ag ) or carcinoembryonic antigen (CEA), Serum CYFRA 21-1 level increased signi ficantly along with the clinical stages, In addition, serum CYFRA 21-1 leve l served as a prognostic factor for patients with oesophageal carcinoma aft er surgery, whilst SSC-Ag and CEA is not connected with the outcome. These findings suggest that the serum CYFRA 21-1 probably originated from the tum our tissue is an important marker for determining the stage and outcome of oesophageal carcinoma.