The relationship between glasgow prognostic score and serum tumor markers in patients with advanced non-small cell lung cancer

Background: Glasgow Prognostic Score (GPS) has been reported as a powerful prognostic tool for patients with advanced non-small cell lung cancer (NSCLC). The aim of this study was to assess the relationship between GPS and prognosis related tumor markers in patients with advanced NSCLC. Methods: We included 138 advanced NSCLC patients and twenty healthy controls in the study. GPS was calculated by combined serum C-reactive protein (CRP) and albumin. Three serum tumor markers, which included cytokeratin 19 fragment antigen 21-1 (CYFRA21-1), carcinoembryonic antigen (CEA) and tissue polypeptide specific antigen (TPS), were detected by enzyme-linked immunosorbent assay (ELISA). GPS and tumor markers were all assessed before chemotherapy. All patients received at least 2 courses of cisplatin-based chemotherapy. After that, 2 to 5 years follow-up was conducted. Results: Median levels of CYFRA21-1 were 1.5 ng/ml (0.1-3.1 ng/ml) in healthy controls, and 4.6 ng/ml (0.7-35.2 ng/ml) in GPS 0 advanced NSCLC, 11.2 ng/ml (0.4-89.2) ng/ml in GPS 1 advanced NSCLC, and 15.7 ng/ml (2.9-134.6 ng/ml) in GPS 2 advanced NSCLC, respectively. Median levels of CYFRA21-1 were higher in NSCLC patients than in healthy controls, and CYFRA21-1 increased gradually according to GPS category in NSCLC patients (P < 0.05). Similar results were found for median levels of CEA and TPS in healthy controls and NSCLC patients (P < 0.05). In NSCLC patients, positive correlations were found between CYFRA21-1 and GPS, CEA and GPS, TPS and GPS. The Spearman's rank correlation coefficient were 0.67 (P < 0.05), 0.61 (P < 0.05) and 0.55 (P < 0.05), respectively. Survival analyses showed GPS was an independent prognostic factor for advanced NSCLC. CYFRA21-1(> 3.3 ng/ml) and TPS (> 80 U/l) were related with the prognosis of advanced NSCLC by univariate analyses, but multivariate analyses showed CYFRA21-1, TPS and CEA were not the independent prognostic factors for advanced NSCLC. Conclusions: Our results showed GPS were positive correlated with CYFRA21-1, CEA and TPS in patients with advanced NSCLC. However, GPS was more efficient in predicting prognosis of advanced NSCLC than these three single prognosis related tumor markers.