Clinicopathological significance of combined analysis of cytokeratin19 expression and preoperative serum CYFRA21-1 levels in human lung squamous cell carcinoma.

BACKGROUND

To identify a useful biomarker for human lung squamous cell carcinoma (SCC), the expression of cytokeratin19 (CK19) in human SCC tissue was investigated. In addition, we examined the significance of CK19 expression levels by immunostaining and CYFRA21-1 levels in preoperative serum, and their correlation with the clinicopathologic features of human lung SCC.

METHODS

To identify proteins in cancerous and non-cancerous tissues for the diagnosis and prognosis of SCC, QSTAR Elite LC-MS/MS was used. Immunostaining for CK19 was classified as either "CK19-strong" or "CK19-weak". Correlations between prognosis and both CK19 expression in tumor tissues and serum concentrations of CYFRA 21-1 were analyzed in 107 cases of lung SCC.

RESULTS

The upregulation of CK19 in human squamous cell carcinoma tissues was observed by LCMS/MS. The weak expression of CK19, as determined by immunostaining intensity, was a significant predictor of poorer disease-specific survival (p = 0.032). The prognosis was significantly poorer for patients with weak CK19 immunostaining in tumor tissues and a high serum concentration of CYFRA21-1 compared with the other groups (p = 0.003).

CONCLUSIONS

The combination of weak CK19 expression and high serum CYFRA21-1 levels is a predictor of poorer prognosis for patients with human lung SCC.