Long-term outcomes of induction chemotherapy followed by intensity-modulated radiotherapy and adjuvant chemotherapy in nasopharyngeal carcinoma patients with N3 disease

Objectives: To evaluate long-term outcomes of induction chemotherapy (IC) followed by intensity-modulated radiotherapy (IMRT) and adjuvant chemotherapy (AC) in nasopharyngeal carcinoma (NPC) patients with N3 disease. Materials and methods: From September 2005 to August 2016, 143 patients confirmed NPC with the 8th AJCC/UICC staging criteria N3 were reviewed. All patients received IC followed by IMRT and AC. Results: After a median follow-up of 67 months, the 5-year and 10-year overall survival (OS), progression-free survival (PFS), distant metastasis free survival (DMFS), local progression-free survival (LPFS) and regional progression-free survival (RPFS) were 75.7% and 61.6%, 61.2% and 53.4%, 73.1% and 72.1%, 92.4% and 87%, 88.9% and 81.8%, respectively. Multivariate analyses indicated that T stage (P = 0.001) appeared to be prognostic factors for OS. T stage (P = 0.001 and P = 0.002) and neck lymph node necrosis (P = 0.015 and P = 0.045) were independent predictors of PFS and DMFS. The acute toxicities were mainly grade 1/2 hematologic toxicities in patients treated with IC+IMRT+AC, and severe toxicities were uncommon. Conclusions: IC followed by IMRT and AC achieved satisfactory long-term survival outcomes in NPC patients with N3 disease. Neck lymph node necrosis and late T stage served as predictors of poor prognosis for patients.