Antineoplastic Combined Chemotherapy Protocols 1 Article 1 Chemoradiotherapy 1 Disease-Free Survival 1 Humans 1 Maintenance Chemotherapy 1 Maintenance chemotherapy 1 N3 Nasopharyngeal Carcinoma 1 Nasopharyngeal Neoplasms 1 Nasopharyngeal carcinoma 1 Neoplasm Recurrence, Local 1 Optimal duration 1 Retrospective Studies 1 S-1 1 adult 1 aged 1 antineoplastic agent 1 cancer patient 1 cancer staging 1 cancer survival 1 chemoradiotherapy 1 controlled study 1 disease free survival 1 distant metastasis free survival 1 drug efficacy 1 fatigue 1 female 1 follow up 1 human 1