Outcomes of Adding Induction Chemotherapy to Concurrent Chemotherapy for Nasopharyngeal Carcinoma Patients with Moderate-Risk in the Intensity-Modulated Radiotherapy Era

Background: The aim of this study was to evaluate the efficacy of induction chemotherapy (IC) in nasopharyngeal carcinoma (NPC) patients with moderate-risk treated with intensity-modulated radiotherapy (IMRT). Methods: We retrospectively assessed 506 patients with T1-2N1M0 or T3-4N0-1M0 NPC (according to the 2010 UICC/AJCC staging system) who received concurrent chemoradiotherapy (CCRT) with or without IC at a single center in China between 2005 and 2010. Survival outcomes were compared between the IC + CCRT and CCRT groups using the Kaplan-Meier method, Log-rank test and a Cox regression model. Results: Among the 506 patients, CCRT alone resulted in equivalent overall survival (86.8% vs 88.5%, p=0.661), progression-free survival (79.6% vs 79.6%, p=0.756), locoregional relapse-free survival (90.2% vs 87.0%, p=0.364) and distant metastasis-free survival (88.0% vs 89.8%, p=0.407) to IC plus CCRT. In multivariate analysis, IC did not lower the risk of death (HR 0.76, 95% CI 0.46-1.25, p=0.278), progression (HR 0.78, 95% CI 0.51-1.19, p=0.244), locoregional relapse (HR 1.06, 95% CI 0.81-1.42, p=0.651) or distant metastasis (HR 0.66, 95% CI 0.38-1.15, p=0.140) in the entire cohort; similar results were obtained in stratified analysis based on N category (N0 vs N1) and EBV DNA (< vs ≥4000 copies/mL). Conclusion: Addition of IC to CCRT does not improve survival outcomes in moderate-risk NPC; the use of IC should be carefully considered in these patients, though additional prospective trials are warranted to confirm the conclusions of this study.