Maintenance chemotherapy using S-1 following definitive chemoradiotherapy in patients with N3 nasopharyngeal carcinoma

Background Patients with N3 stage nasopharyngeal carcinoma (NPC) are at high risk for treatment failure. This study aims to assess the efficacy of maintenance chemotherapy (MC) using S-1 (MC-S1), a novel oral fluoropyrimidine agent, following definitive chemoradiotherapy (CRT) using intensity-modulated radiotherapy (IMRT) in patients with N3 nasopharyngeal carcinoma (N3-NPC).