Effect of local treatment for metastasis and its sequence with chemotherapy on prognosis of post-treatment metastatic nasopharyngeal carcinoma patients

Distant metastasis after chemoradiotherapy remains the leading cause of death in NPC patients. But the effect of local treatment for metastatic sites and its sequence with chemotherapy on prognosis of them are poorly documented. 448 post-treatment metastatic NPC patients were included in our retrospective study. And Cox regression and log-rank tests were applied to investigate the association between topical treatment and its sequence with chemotherapy and survival using the propensity score method (PSM) to adjust for gender, age, Tumor stage, Node stage, metastatic sites, diabetes and smoking with a 1:2 matching protocol. The 3-year OS was significantly higher in patients who received local treatment of distant metastasis compared with patients who did not (48.8% vs 33.8%, P = 0.001) in primary cohort. PSM identified 120 patients in the cohort with local treatment and 240 in that without and similar survival benefits were observed for the local treatment (3-year OS: 36.2% versus 48.8%, P = 0.011). Subgroup analyses indicated that there was no significant survival difference in patients with different treatment sequence. In conclusion, post-treatment metastatic NPC patients could be beneficial from local treatment for metastasis but its sequence with palliative chemotherapy does not affect overall survival.