Prognostic score for second-line chemotherapy of advanced non-small cell lung cancer (NSCLC): External validation in a phase III trial comparing vinflunine with docetaxel.

Abstract

7556 Background: Prognostic index for second-line chemotherapy of NSCLC was previously developed, based on individual patient data (IPD) of 9 randomized trials (Table) (Di Maio et al, Eur J Cancer 2010; 46: 735-743). In this study, we aimed to validate the prognostic score, with the use of an external dataset. Methods: We analyzed IPD of patients (pts) enrolled in a non-inferiority phase III trial comparing vinflunine vs. docetaxel in second-line treatment of advanced NSCLC. The study showed similar efficacy for both agents. Primary endpoint of this analysis was overall survival (OS). The following variables were considered for survival analysis and score calculation: gender, performance status (PS), extent of disease, tumor histotype, type of first-line treatment, response to first-line treatment. Cox model, stratified by treatment arm, was used for multivariate analysis. Individual prognostic scores were derived according to our scoring system, and pts were divided into 3 categories according to the score: <5 (best), 5-9 (intermediate), >9 (worst). Results: All 551 pts enrolled in the trial had complete information for prognostic score calculation. Median OS in all pts was 6.9 months. Median OS was 12.9, 6.9 and 3.8 months for the best, intermediate and worst categories, respectively. Cox model analysis showed a significant effect for intermediate vs. best category comparison (hazard ratio 1.79, 95%CI 1.31 - 2.47, p=0.0003) and for worst vs. best category comparison (hazard ratio 3.25, 95%CI 2.18 - 4.83, p<0.0001). The C-index of the model was high (0.926), indicating a good discrimination according to the proposed risk categories. Conclusions: Prognostic ability of our score for candidates to second-line treatment in advanced NSCLC was validated. Subgroups of patients with more vs. less favorable prognosis were identified. Prognostic score could be useful in clinical practice. Scoring system. Points 0 1 2 7 Gender Female Male ECOG PS 0 1 2 Tumor stage IIIb (locally advanced) IV (metastatic) Histologic type Adenocarcinoma Squamous Other Type of first-line Without platinum Platin-based Objective response to first-line Yes No