Optimizing the treatment mode for de novo metastatic nasopharyngeal carcinoma with bone-only metastasis

Abstract

Abstract Background No standard radiotherapy regimens have been established for the treatment of de novo metastatic nasopharyngeal carcinoma (mNPC) with bone-only metastasis. The current study aimed to investigate the efficacy of palliative chemotherapy (PCT) plus locoregional radiotherapy (LRRT) with or without local radiotherapy (RT) for metastatic bone lesions in mNPC. Methods We retrospectively analysed 131 de novo patients with mNPC who had bone-only metastasis and received at least two cycles of PCT with LRRT. The difference in survival was evaluated by the log-rank test. Univariable and multivariable analyses were performed by Cox regression. Results The median overall survival (OS) and progression-free survival (PFS) were 33.0 months and 24.0 months, respectively. Patients with five or fewer metastatic bone lesions had significantly longer OS (72.0 months vs. 23.0 months, Hazard ratios (HR) = 0.45, p 0.05). Patients who received a RT dose > 30 Gy had neither better OS (63.5 months vs. 32.0 months, p = 0.299) nor PFS (48.0 months vs. 28.0 months, p = 0.615) than those who received a RT dose ≤30 Gy. Conclusions Local RT to bone metastases may not significantly improve survival in patients with de novo mNPC with bone-only metastasis who have already received PCT plus LRRT. Receiving four or more cycles of chemotherapy can significantly prolong survival and is a favourable independent protective factor.