Abstract
OBJECTIVES: Previous studies have shown that Glasgow prognostic score (GPS) and prognostic index (PI) are also powerful prognostic tool for patients with advanced non-small cell lung cancer (NSCLC). The aim of this study was to compare the prognostic value between GPS and PI. METHODS: We enrolled consecutive patients with advanced NSCLC in this prospective cohort. GPS and PI were calculated before the onset of chemotherapy. The prognosis outcomes included 1-, 3-, and 5-year progression-free survival and overall survival (OS). The performance of two scores in predicting prognosis was analyzed regarding discrimination and calibration. RESULTS: 138 patients were included in the study. The area under the receiver operating characteristic curve for GPS predicting 1-year DFS was 0.62 (95 % confidence interval (CI) 0.56-0.68, P < 0.05), and the area under curve for PI predicting 1-year DFS was 0.57 (95 % CI 0.52-0.63). Delong's test showed that GPS was more accurate than PI in predicting 1-year DFS (P < 0.05). Similar results of discriminatory power were found for predicting 3-year DFS, 1-year OS, and 3-year OS. The predicted 1-year DFS by GPS 0, GPS 1, and GPS 2 were 62.5, 42.1, and 23.1 %, respectively, while actual 1-year DFS by GPS 0, GPS 1, and GPS 2 were 61.1, 43.8, and 27.2 %, respectively. Calibration of the Hosmer and Lemeshow statistic showed good fit of the predicted 1-year DFS to the actual 1-year DFS by GPS (χ(2) = 4.326, P = 0.462), while no fit was found between the predicted 1-year DFS and the actual 1-year DFS by PI (χ(2) = 15.234, P = 0.091). Similar results of calibration power were found for predicting 3-year DFS, 5-year DFS, 1-year OS, 3-year OS, and 5-year OS by GPS and PI. CONCLUSIONS: GPS is more accurate than PI in predicting prognosis for patients with advanced NSCLC. GPS can be used as a useful and simple tool for predicting prognosis in patients with NSCLC. However, GPS only can be used for preliminary assessment because of low predicting accuracy.