Induction chemotherapy followed by concurrent chemoradiotherapy versus concurrent chemoradiotherapy alone in stage III-IVb nasopharyngeal carcinoma patients with Epstein-Barr virus DNA ≥4000 copies/ml: a matched study

// Shan-Shan Guo 1, 2, * , Lin-Quan Tang 1, 2, * , Qiu-Yan Chen 1, 2 , Lu Zhang 1, 2 , Li-Ting Liu 1, 2 , Ling Guo 1, 2 , Hao-Yuan Mo 1, 2 , Dong-Hua Luo 1, 2 , Pei-Yu Huang 1, 2 , Yan-Qun Xiang 1, 2 , Rui Sun 1, 2 , Ming-Yuan Chen 1, 2 , Lin Wang 1, 2 , Xing Lv 1, 2 , Chong Zhao 1, 2 , Xiang Guo 1, 2 , Ka-Jia Cao 1, 2 , Chao-Nan Qian 1, 2 , Mu-Shen Zeng 1 , Jin-Xin Bei 1 , Ming-Huang Hong 1, 3 , Jian-Yong Shao 1, 4 , Ying Sun 1, 5 , Jun Ma 1, 5 , Hai-Qiang Mai 1, 2 1 Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China 2 Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou 510060, China 3 Good Clinical Practice center, Sun Yat-sen University Cancer Center, Guangzhou 510060, China 4 Department of Molecular Diagnostics, Sun Yat-sen University Cancer Center, Guangzhou 510060, China 5 Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China * These authors have contributed equally to this work Correspondence to: Hai-Qiang Mai, e-mail: maihq@sysucc.org.cn Keywords: nasopharyngeal carcinoma, induction chemotherapy, concurrent chemotherapy, IMRT, EBV DNA Received: November 22, 2015 Accepted: March 28, 2016 Published: April 18, 2016 ABSTRACT Background: The effects of induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT) in high-risk (stage III-IVb with EBV DNA≥4000 copies/ml) nasopharyngeal carcinoma (NPC) patients are unclear. Methods: A total of 325 high-risk NPC patients treated with IC+CCRT or CCRT alone who were treated with intensity-modulated radiation therapy (IMRT) between March 2007 and March 2013 were included. For each patient in the IC+CCRT group, a matched pair in the CCRT group was matching for: gender, age, T stage, N stage, clinical stage and WHO (World Health Organization) type. The primary endpoint was overall survival (OS), and the secondary endpoints were progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRFS). Results: There were no significant differences in OS, PFS, DMFS, and LRFS between the IC+CCRT (148 patients) and CCRT (177 patients) groups. After matching, 103 paired patients were analyzed, and there were no differences between the IC+CCRT and CCRT groups regarding clinical outcomes. Based on the subgroup analysis of 156 very-high-risk patients (stage N2-3 with EBV DNA ≥4000 copies/ml), the 5-year OS of the IC+CCRT and CCRT groups was 84.3% and 67.5% (P =0.033), respectively. Based on our multivariate analysis, the treatment group was significantly associated with OS (P=0.034; HR0.451, 95%CI 0.216-0.941). Conclusions : IC+CCRT did not improve the clinical outcomes of high-risk NPC patients compared to CCRT alone. However, in very-high-risk patients, IC+CCRT treatment led to increased OS compared to patients received CCRT treatment alone.