Induction chemotherapy followed by concurrent chemoradiotherapy versus concurrent chemoradiotherapy alone in locoregionally advanced nasopharyngeal carcinoma: long-term results of a phase III multicentre randomised controlled trial

Background Initial 3-year results from our clinical trial in locoregionally advanced nasopharyngeal carcinoma (NPC) patients showed that induction chemotherapy (IC) with cisplatin and fluorouracil resulted in improved disease-free survival (DFS) with a marginally significant effect on distant metastasis-free survival (DMFS), but the effect of IC on locoregional relapse-free survival and overall survival (OS) did not differ significantly. Here, we present 5-year follow-up results. Patients and methods Our trial was a randomised, open-label phase III trial comparing IC followed by concurrent chemoradiotherapy (CCRT) versus CCRT alone in patients with stage III-IVB (except T3N0-1) NPC. The IC followed by CCRT group received cisplatin (80 mg/m2 d1) and fluorouracil (800 mg/m2 d1-5) every 3 weeks for two cycles before CCRT. Both groups were treated with 80 mg/m2 cisplatin every 3 weeks concurrently with radiotherapy. The primary end-points were DFS and DMFS. We did efficacy analyses in the 476 randomised patients (intention-to-treat population). Results After a median follow-up of 82.6 months, the 5-year DFS rate was 73.4% (95% confidence interval [CI] 67.7–79.1) in the IC followed by CCRT group and 63.1% (95% CI 56.8–69.4) in the CCRT alone group (p = 0.007). The 5-year DMFS rate was also significantly higher in the IC followed by CCRT group (82.8%, 95% CI 77.9–87.7) than in the CCRT alone group (73.1%, 95% CI 67.2–79.0, p = 0.014). Our updated analysis revealed an OS benefit of IC: the 5-year OS rate was 80.8% in the IC followed by CCRT group versus 76.8% in the CCRT alone group (p = 0.040). The proportion of patients with eye damage was significantly higher in the CCRT alone group than the IC followed by CCRT group (16.4% [39/238] versus 9.7% [23/238], p = 0.029). Conclusion IC followed by CCRT provides long-term DFS, DMFS and OS benefits compared with CCRT alone in locoregionally advanced NPC and, therefore, can be recommended for these patients.