Survival analysis of patients with advanced-stage nasopharyngeal carcinoma according to the Epstein-Barr virus status

Abstract

// Hao Peng 1 , Lei Chen 1 , Yuan Zhang 1 , Rui Guo 1 , Wen-Fei Li 1 , Yan-Ping Mao 1 , Ling-Long Tan 1 , Ying Sun 1 , Fan Zhang 1 , Li-Zhi Liu 2 , Li Tian 2 , Ai-Hua Lin 3 , Jun Ma 1 1 Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, People’s Republic of China 2 Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, People’s Republic of China 3 Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510275, People’s Republic of China Correspondence to: Jun Ma, e-mail: majun2@mail.sysu.edu.cn Keywords: nasopharyngeal carcinoma, Epstein-Barr virus, prognosis, advanced stage, intensity-modulated radiation therapy Received: October 30, 2015     Accepted: March 04, 2016     Published: March 17, 2016 ABSTRACT Purpose : The main aim of this study is to analyze the prognostic differences in nasopharyngeal carcinoma (NPC) patients who are positive and negative for Epstein-Barr virus (EBV).   Results : Of the 1106 patients, 248 (22.4%) had undetectable pre-treatment plasma EBV DNA levels. The total distant metastasis rate for EBV-negative group vs. EBV-positive group were 3.6% (9/248) vs. 15.0% (128/858) ( P < 0.001). The estimated 4-year disease-free survival (DFS), overall survival (OS), distant metastasis-free survival (DMFS) and locoregional relapse-free survival (LRRFS) for EBV-negative group vs. EBV-positive group were 88.9% vs. 76.9% ( P < 0.001), 93.6% vs. 85.9% ( P = 0.001), 96.7% vs. 84.8% ( P < 0.001) and 94.1% vs. 90.0% ( P = 0.1), respectively. Multivariate analysis revealed that the EBV status was an independent prognostic factor for DFS (HR, 1.813; 95% CI, 1.219-2.695; P = 0.003), OS (HR, 1.828; 95% CI, 1.075-3.107; P = 0.026) and DMFS (HR, 3.678; 95% CI, 1.859-7.277; P <0.001), and overall stage still remained the most important prognostic factor in patients with stage III-IVB NPC. Methods and Materials : Data on 1106 patients with non-metastatic, histologically proven advanced-stage (III-IVB) NPC who underwent intensity-modulated radiotherapy (IMRT) were retrospectively reviewed. Patient survival between different EBV status groups were compared. Conclusions : EBV status was an independent prognostic factor for patients with stage III–IVB NPC. Neoadjuvant chemotherapy (NCT) plus concurrent chemoradiotherapy (CCRT) should be better treatment regimen for EBV-positive patients since distant metastasis was the main failure pattern, and CCRT may be enough for EBV-negative patients.