Serum CYFRA 21-1 but not Vimentin is Associated with Poor Prognosis in Advanced Lung Cancer Patients

BACKGROUND: Cytokeratins and Vimentin are intermediate filament proteins. Vimentin expression in tissue samples has been reported to be associated with a poor prognosis in non-small cell lung cancer patients who underwent surgery. CYFRA 21-1 (Cytokeratin 19 Fragment) is a well known tumor marker. OBJECTIVE: This study aimed to investigate the usefulness of serum vimentin as a tumor marker and significance of CYFRA 21-1 and vimentin expression on prognosis of advanced lung cancer patients. METHODS: One hundred and four advanced lung cancer patients and 19 non-lung cancer patients were included. A total of 157 clinical samples obtained from 113 patients was used for immunostaining of vimentin and measurements of CYFRA 21-1 and vimentin concentrations. RESULTS: Compared to low concentration, high concentration of serum CYFRA 21-1 was associated with shorter overall survival in lung cancer patients. However, there was no difference in the serum vimentin concentration between the patients with lung cancer and those with non-lung cancer. No difference in vimentin concentration was observed between the malignant and non-malignant pleural effusions. Immunostaining revealed that of the 43 tumor samples, 21 were positive and 22 were negative for vimentin. No significant difference was found in overall survival between patients with positive and negative for vimentin. CONCLUSION: An elevated serum CYFRA 21-1 concentration was associated with shorter overall survival in advanced lung cancer patients. However, serum vimentin was not as useful as a tumor marker of lung cancer. The vimentin positivity in tumor samples might not predict patients’ prognosis in patients with advanced lung cancer.