Phase III study of concurrent chemoradiotherapy versus radiotherapy alone for advanced nasopharyngeal carcinoma: positive effect on overall and progression-free survival. PURPOSE: Nasopharyngeal carcinoma (NPC) is a radiosensitive and chemosensitive tumor. This randomized phase III trial compared concurrent chemoradiotherapy (CCRT) versus radiotherapy (RT) alone in patients with advanced NPC. PATIENTS AND METHODS: From December 1993 to April 1999, 284 patients with 1992 American Joint Committee on Cancer stage III to IV (M0) NPC were randomly allocated into two arms. Similar dosage and fractionation of RT was administered in both arms. The investigational arm received two cycles of concurrent chemotherapy with cisplatin 20 mg/m(2)/d plus fluorouracil 400 mg/m(2)/d by 96-hour continuous infusion during the weeks 1 and 5 of RT. Survival analysis was estimated by the Kaplan-Meier method and compared by the log-rank test. RESULTS: Baseline patient characteristics were comparable in both arms. After a median follow-up of 65 months, 26.2% (37 of 141) and 46.2% (66 of 143) of patients developed tumor relapse in the CCRT and RT-alone groups, respectively. The 5-year overall survival rates were 72.3% for the CCRT arm and 54.2% for the RT-only arm (P =.0022). The 5-year progression-free survival rates were 71.6% for the CCRT group compared with 53.0% for the RT-only group (P =.0012). Although significantly more toxicity was noted in the CCRT arm, including leukopenia and emesis, compliance with the combined treatment was good. The second cycle of concurrent chemotherapy was refused by nine patients and was delayed for > or = 1 week for another nine patients. There were no treatment-related deaths in either arm. CONCLUSION: We conclude that CCRT is superior to RT alone for patients with advanced NPC in endemic areas.