Induction Chemotherapy plus Concurrent Chemoradiotherapy in Endemic Nasopharyngeal Carcinoma: Individual Patient Data Pooled Analysis of Four Randomized Trials.

Purpose: Because of the uneven geographic distribution and small number of randomized trials available, the value of additional induction chemotherapy (IC) to concurrent chemoradiotherapy (CCRT) in nasopharyngeal carcinoma (NPC) remains controversial. This study performed an individual patient data (IPD) pooled analysis to better assess the precise role of IC + CCRT in locoregionally advanced NPC.Experimental Design: Four randomized trials in endemic areas were identified, representing 1,193 patients; updated IPD were obtained. Progression-free survival (PFS) and overall survival (OS) were the primary and secondary endpoints, respectively.
Results: Median follow-up was 5.0 years. The HR for PFS was 0.70 [95% confidence interval (CI), 0.56-0.86; P = 0.0009; 9.3% absolute benefit at 5 years] in favor of IC + CCRT versus CCRT alone. IC + CCRT also improved OS (HR = 0.75; 95% CI, 0.57-0.99; P = 0.04) and reduced distant failure (HR = 0.68; 95% CI, 0.51-0.90; P = 0.008). IC + CCRT had a tendency to improve locoregional control compared with CCRT alone (HR = 0.70; 95% CI, 0.48-1.01; P = 0.06). There was no heterogeneity between trials in any analysis. No interactions between patient characteristics and treatment effects on PFS or OS were found. After adding two supplementary trials to provide a more comprehensive overview, the conclusions remained valid and were strengthened. In a supplementary Bayesian network analysis, no statistically significant differences in survival between different IC regimens were detected.Conclusions: This IPD pooled analysis demonstrates the superiority of additional IC over CCRT alone in locoregionally advanced NPC, with the survival benefit mainly associated with improved distant control. Clin Cancer Res; 24(8); 1824-33. ©2018 AACR. ©2018 American Association for Cancer Research.