Effects of Surgery Combined with Chemoradiotherapy on Short- and Long-Term Outcomes of Early-Stage Nasopharyngeal Carcinoma.

ABSTRACT

OBJECTIVE: The efficacy of surgery as the primary treatment modality for nasopharyngeal carcinoma (NPC) is yet to be clarified. Therefore, we aimed to explore the short- and long-term efficacy of surgery for early-stage NPC. METHODS: We retrospectively evaluated 341 patients diagnosed with early-stage NPC between September 2010 and December 2015. Among them, 58 patients underwent endoscopic nasopharyngectomy combined with chemoradiotherapy, whereas 283 patients underwent conventional chemoradiotherapy. The patients who underwent concurrent chemoradiotherapy or radiotherapy alone were matched to patients who underwent surgery in a 12 ratio using propensity score matching to analyze the clinical efficacy of each therapeutic modality. The primary endpoint was survival, and the secondary endpoints were tumor regression rate and reduction in Epstein-Barr virus (EBV)-DNA levels. RESULTS: After matching, 156 patients were enrolled (58 patients in the surgery group; 98 patients in the non-surgery group). The baseline data of the matched patients had good inter-group comparability (All P>0.05). The surgery group had significantly higher 5-year overall survival (98.30% vs. 91.70%), disease-free survival (98.30% vs. 81.40%), and recurrence-free survival (100.00% vs. 90.10%) rates than did the non-surgery group (All P<0.05). In total, 0 and 14 patients in the surgery and non-surgery groups, respectively, had residual cancer at the end of treatment (P=0.001). All patients in the surgery group tested negative for EBV-DNA, whereas two patients in the non-surgery group tested positive. The incidence of hematologic toxicity during treatment was similar between the two groups (All P>0.05). Still, the incidence of severe oral mucositis was lower in the surgery group than in the non-surgery group (37.9% vs. 54.08%, P=0.051). CONCLUSION: Surgery can improve the clearance rate of EB virus and reduce tumor residue. Surgery may be a safe and effective treatment for early NPC.