Safety and efficacy of S-1 chemotherapy in recurrent and metastatic nasopharyngeal carcinoma patients after failure of platinumbased chemotherapy: multi-institutional retrospective analysis

Purpose: This retrospective study evaluates the efficacy and safety of S-1 chemotherapy for recurrent and metastatic nasopharyngeal carcinoma patients after failure of platinum-based chemotherapy. Patients and methods: Thirty-nine patients with recurrent and metastatic nasopharyngeal carcinoma who failed previous platinum-based chemotherapy received oral S-1 chemotherapy (twice daily from day 1 to 14) every 3 weeks. The dose of S-1 was determined according to the body surface area (BSA): 40 mg twice a day for BSA <1.25 m(2); 50 mg twice a day for 1.25 m(2) <= BSA<1.5 m(2); and 60 mg twice a day for BSA >= 1.5 m(2). Results: Treatment was well tolerated. Most adverse events were mild. Grade 3 hematological toxicity occurred in 7.7%. There was one complete response (2.6%) and 12 partial responses (30.7%), giving an overall response rate of 33.3% (95% CI [confidence interval], 21.7-50.8). Median time-to-progression was 5.6 months, and median survival was 13.9 months. One-and 2-year survival rates were 60% and 26%, respectively. Conclusion: S-1 monotherapy is considered a safe and effective treatment option for recurrent and metastatic nasopharyngeal carcinoma patients after failure of platinum-based chemotherapy.