Systemic chemotherapy followed by locoregional definitive intensity-modulated radiation therapy yields prolonged survival in nasopharyngeal carcinoma patients with distant metastasis at initial diagnosis

Chemotherapy is the current mainstay of treatment for patients with newly diagnosed metastatic nasopharyngeal carcinoma (NPC), whereas the role of locoregional radiotherapy remains to be defined. In this study, we retrospectively evaluated the outcome of systemic chemotherapy followed by locoregional definitive intensity-modulated radiation therapy (IMRT) as first-line treatment for these patients. Forty-one patients with pathologically confirmed NPC with distant metastasis at initial diagnosis seen between March 2005 and February 2014 were included. All the patients were treated with platinum-based systemic chemotherapy followed by definitive IMRT to the primary head and neck region with or without concurrent chemotherapy. In addition, local treatment to metastatic lesions was given in 19 patients. With a median follow-up time of 25 months, 24 patients had died, and the estimated median overall survival time was 31.2 months. The 1-, 2-, 3- and 5-year estimated OS rates were 89.9, 67.4, 41.1 and 22.5 %, respectively. Prognostic analyses showed that serum lactate dehydrogenase level ( P = 0.021) and number of metastatic sites (single vs. multiple; P = 0.016) were significant prognostic factors. Five patients are still alive without evidence of disease after 52 to >101 months. All of them had a single metastatic lesion and received local treatment to metastatic sites. These results suggest that the use of definitive IMRT to treat the locoregional tumor in combination with systemic chemotherapy may prolong survival in patients with newly diagnosed metastatic NPC, making curability a possible consideration in selected patients with single metastasis. Further prospective clinical trials are warranted.