Clinical trials frequently include multiple end points that mature at different times. The initial report, typically on the based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We previously reported significantly improved failure-free survival using gemcitabine plus cisplatin induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma. Here, we present the final overall survival (OS) analysis. In this multicenter, randomized trial, patients were assigned to be treated with concurrent chemoradiotherapy alone (standard therapy, n = 238) or gemcitabine and cisplatin induction chemotherapy before concurrent chemoradiotherapy (n = 242). With a median follow-up of 69.8 months, the induction chemotherapy group had a significantly higher 5-year OS (87.9% v 78.8%, hazard ratio, 0.51 [95% CI 0.34 to 0.78]; P = .001) and a comparable risk of late toxicities (≥ grade 3, 11.3% v 11.4%). Notably, the depth of the tumor response to induction chemotherapy correlated significantly and positively with survival (complete response v partial response v stable/progressive disease, 5-year OS, 100% v 88.4% v 61.5%, P = .005). Besides, patients with a low pretreatment cell-free Epstein-Barr virus DNA load (< 4,000 copies/mL) might not benefit from induction chemotherapy (5-year OS, 90.6% v 91.4%, P = .77). In conclusion, induction chemotherapy before concurrent chemoradiotherapy improved OS significantly in patients with locally advanced nasopharyngeal carcinoma, without increasing the risk of late toxicities. Tumor response to induction chemotherapy and pretreatment cell-free Epstein-Barr virus DNA might be useful to guide individualized treatment.
Trial registration: ClinicalTrials.gov NCT01872962.