Cycle number of neoadjuvant chemotherapy might influence survival of patients with T1-4N2-3M0 nasopharyngeal carcinoma

Objective: Stage N2-3 nasopharyngeal carcinoma (NPC) shows a high risk of distant metastasis, which will finally cause death. This study aimed to evaluate the impact of neoadjuvant chemotherapy (NACT) of various cycles before radical radiotherapy on distant metastasis and survival of patients with stage N2-3 diseases. Methods: In this study, a total of 1,164 consecutive patients with non-metastatic N2-3 NPC were recruited and prospectively observed. Then 231 patients who received NACT of 4 cycles (NACT= 4 group) were matched 1: 2: 1 to 462 patients treated with NACT of 2 cycles (NACT= 2 group) and 231 patients treated without NACT (NACT= 0 group), according to age, histological subtype, N stage and NACT regimen. Five candidate variables (sex, T stage, concurrent chemotherapy, intensity-modulated radiation therapy and cycle number of NACT) were analyzed for their association with patients' survival. Results: After matching, the overall survival (OS), disease-free survival (DFS), local-recurrence-free survival (RFS) and distant-metastasis-free survival (MFS) of the NACT= 4 group (89.2%, 81.0%, 83.3% and 84.8%, respectively) were better than those of the NACT= 2 group (83.3%, 72.5%, 81.2% and 77.9%, respectively) and the NACT= 0 group (74.0%, 63.2%, 74.0% and 68.8%, respectively). In multivariate analysis, the cycle number of NACT maintained statistical significance on the OS, DFS, RFS and MFS (all P<0.05). Conclusions: For N2-3 NPC, cycle number of NACT appeared to be an independent factor associated with an improvement of survival.