Efficacy and Safety of Locoregional Radiotherapy With Chemotherapy vs Chemotherapy Alone in De Novo Metastatic Nasopharyngeal Carcinoma

Importance The role of locoregional radiotherapy in patients with de novo metastatic nasopharyngeal carcinoma (mNPC) is unclear. Objective To investigate the efficacy and safety of locoregional radiotherapy in de novo mNPC. Design, Setting, and Participants Patients with biopsy-proven mNPC, who demonstrated complete or partial response (RECIST v1.1) following 3 cycles of cisplatin and fluorouracil chemotherapy, were enrolled. Eligible patients were randomly assigned (1:1) to receive either chemotherapy plus radiotherapy or chemotherapy alone. Overall, 126 of 173 patients screened were eligible to the study, and randomized to chemotherapy plus radiotherapy (n = 63) or chemotherapy alone (n = 63). Median (IQR) follow-up duration was 26.7 (17.2-33.5) months. Interventions The chemotherapy regimens were fluorouracil continuous intravenous infusion at 5 g/m2over 120 hours and 100 mg/m2intravenous cisplatin on day 1, administered every 3 weeks for 6 cycles. Patients assigned to the chemotherapy plus radiotherapy group received intensity-modulated radiotherapy (IMRT) after chemotherapy. Main Outcomes and Measures The primary end point of the study was overall survival (OS). The secondary end point was progression-free survival (PFS) and safety. Results Overall, 126 patients were enrolled (105 men [83.3%] and 21 women [16.7%]; median [IQR] age, 46 [39-52] years). The 24-month OS was 76.4% (95% CI, 64.4%-88.4%) in the chemotherapy plus radiotherapy group, compared with 54.5% (95% CI, 41.0%-68.0%) in the chemotherapy-alone group. The study met its primary end point of improved OS (stratified hazard ratio [HR], 0.42; 95% CI, 0.23-0.77;P = .004) in favor of chemotherapy plus radiotherapy. Progression-free survival was also improved in the chemotherapy plus radiotherapy group compared with the chemotherapy-alone group (stratified HR, 0.36; 95% CI, 0.23-0.57). No significant differences in acute hematological or gastrointestinal toxic effects were observed between the treatment arms. The frequency of acute grade 3 or higher dermatitis, mucositis, and xerostomia was 8.1%, 33.9%, and 6.5%, respectively, in the chemotherapy plus radiotherapy group. The frequency of late severe grade 3 or higher hearing loss and trismus was 5.2% and 3.4%, respectively, in the chemotherapy plus radiotherapy group. Conclusions and Relevance In this randomized clinical trial, radiotherapy added to chemotherapy significantly improved OS in chemotherapy-sensitive patients with mNPC. Trial Registration ClinicalTrials.gov Identifier:NCT02111460