Induction Chemotherapy Followed by Concurrent Chemoradiotherapy vs. Concurrent Chemoradiotherapy in T4N0-1M0 Patients With Nasopharyngeal Carcinoma: A Multicenter Retrospective Study.

Abstract

PURPOSE/OBJECTIVE(S)\nInduction chemotherapy followed by concurrent chemoradiotherapy (IC+CCRT) and concurrent chemoradiotherapy (CCRT) are both recommended by guidelines for patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC). Two recent randomized control studies confirmed IC+CCRT had superior treatment outcomes than CCRT. However, most patients enrolled in these studies were staged as N2-N3 and subgroup analysis failed to identify the difference between IC+CCRT and CCRT for T4N0-1 NPC patients. Until now, little is unknown about the treatment modality for T4N0-1 NPC patients because of low incidence for this part of disease. Therefore, we designed this multicenter retrospective study to evaluate these two treatment modalities or T4N0-1 NPC patients.\n\n\nMATERIALS/METHODS\nBetween May 2010 and September 2017, a total of 75 NPC patients with T4N0-1 were reviewed from three hospitals of North West China. All patients received CCRT with or without IC. The IC regimens included TP regimen (docetaxel 75mg/m2, cisplatin 75mg/m2), GP regimen (gemcitabine 1000mg/m2, cisplatin 75mg/m2) and TPF regimen (docetaxel 75mg/m2, cisplatin 75 mg/m2, 5-fluorouracil 750 mg/m2 days1 to 5) every 3 weeks for 2-3 cycles. Concurrent chemotherapy was only consisted of cisplatin (100mg/m2 every 3 weeks). The primary endpoint was disease-free survival (DFS). The secondary endpoints included overall survival (OS), distant metastasis-free survival (DMFS), locoregional recurrence-free survival (LRFS) and toxicities. The measurement data between two groups was compared with χ2 test. Log-rank test were used to analyze the survival outcomes in groups. A 2-sided P value of less than 0.05 was considered as significant.\n\n\nRESULTS\nThe median follow-up time was 38 months (rang: 7-99 months). Of 75 patients, 11 patients died, 6 patients developed distant metastasis disease, and no patients experienced local regional recurrence during the follow-up period. The estimated 3-year OS, DFS and DMFS rates were 83.1%, 86.0% and 91% for all patients, respectively. No significant difference was detected between IC+CCRT and CCRT concerning 3-year DFS (85.6% vs. 80.8%, P\u202f=\u202f0.455), OS (93.0% vs. 80.8%, P\u202f=\u202f0.247) and DMFS (85.6% vs. 95.1%, P\u202f=\u202f0.246) in the whole cohort, respectively. Moreover, we failed to detect statistically significant difference in adverse events between two treatment groups (P > 0.05). By subgroup analysis, IC+CCRT group had significant better OS than CCRT group in patients with N1 stage subgroup (92.0% vs. 65.9%, P\u202f=\u202f0.044). Although no statistically significant difference was detected by subgroup analysis, IC+CCRT had a trend to have a better DFS in patients with stage N1 (88.0% vs. 65.9%, P\u202f=\u202f0.054).\n\n\nCONCLUSION\nIC followed by CCRT did not improve survival outcome in patients with T4N0-1 disease when compared with CCRT. However, patients with N1 stage might get survival benefit from IC+CCRT. Prospective studies and large sample retrospective studies are needed to further confirm this result.