[The prognostic value of cytokeratin 19 expression in non-small cell lung cancer]

Cytokeratins are important part of cytoskeleton. Cytokeratin 19 (CK 19) belongs to type I cytokeratins. Lung cancer is currently most frequently diagnosed neoplasm in males in many developed countries and in Poland. The prognosis in lung cancer remains unfavourable. The aim of this study was to evaluate the prognostic value of cytokeratin 19 expression in non-small cell lung cancer.

We examined the degree of cytokeratin 19 expression in 94 patients with non-small cell lung cancer, who had undergone surgery. The group consisted of 64 men and 30 women. The mean age was 59,12 +/- 8,61 years. Histological diagnosis was squamous cell carcinoma in 59 patients, adenocarcinoma in 26 patients, large cell carcinoma in 5 patients and non-small cell lung cancer without determination of the subtype in 4 patients. Cytokeratin 19 expression was examined immunohistochemically with Monoclonal Mouse Anti-Human Cytokeratin 19 Clone BA 17 DAKO M 0772. All patients were observed for 24 months. 45 patients (48%) survived, 49 died.

In all examined tumors we observed positive cytoplasmatic staining of cytokeratin 19. In 41 cases (44%) it was weak staining (CK 1), in 35 (37%) medium (CK 2) and in 18 (19%) strong one (CK 3). We demonstrated higher expression of cytokeratin 19 in these patients, who survived 2 years (p = 0,003). We also observed relationship between higher expression of CK 19 and survival in patients with squamous cell cancer, but there was no correlation with survival in patients with adenocarcinoma.

Our results suggest that the degree of cytokeratin 19 expression could be a new prognostic factor in non-small cell lung cancer. Cytokeratin 19 expression has prognostic value in patients with squamous cell lung cancer but not in patients with adenocarcinoma.