A retrospective study of concurrent chemoradiotherapy plus S-1 adjuvant chemotherapy on curative effect for treatment of patients with N3 stage nasopharyngeal carcinoma

INTRODUCTION: The purpose of this study was to analyze the efficacy and safety of concurrent chemoradiotherapy plus S-1 adjuvant chemotherapy for N3 stage nasopharyngeal carcinoma (NPC). METHODS: This study included 44 N3 stage NPC patients treated with concurrent chemoradiotherapy plus S-1 adjuvant chemotherapy. The intensity-modulated radiation therapy doses were planning target volume (PTV) 70–72 Gy for gross disease in the nasopharynx and 66–70 Gy for positive lymph nodes. The doses for high-risk- and low-risk region PTV were 60–62 and 54–56 Gy in 31–33 fractions. All patients received a concurrent chemotherapy program consisting of cisplatin 100 mg/m(2), day 1, and the cycle repetition was every 21 days. The adjuvant chemotherapy program consisted of 4 cycles of S-1. 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). S-1 was given on days 1–28, given 6 weeks apart. RESULTS: All 44 patients completed at least 2 cycles of concurrent chemotherapy and 4 cycles of adjuvant chemotherapy. The total efficiency of therapy was 100.0%. The 3-year overall survival (OS), distant metastasis-free survival (DMFS), local-regional control, and progression-free survival rates were 86.4%, 84.1%, 97.7%, and 81.8%, respectively. There were no differences in the OS, DMFS, and efficiency between fast-fading group (reaching partial response before the second cycle of concurrent chemotherapy) and general-fading group (the rest of the group). The incidence of rash in the entire group was low, and there was also no association with prognosis. CONCLUSION: In patients with N3 stage NPC, concurrent chemoradiotherapy plus S-1 adjuvant chemotherapy yielded an excellent survival benefit, and the toxicities were mild and tolerable. Distant metastasis was the main cause of treatment failure.