title: Prognostic efficacy of combining tumor volume with Epstein-Barr virus DNA in patients treated with intensity-modulated radiotherapy for nasopharyngeal carcinoma.
abstract: To evaluate the prognostic effect of combining tumor volume with pre-treatment plasma Epstein-Barr virus DNA (EBV DNA) in patients treated with intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC).
  
  
  
  A total of 180 consecutive NPC patients enrolled in this observational, prospective study and underwent IMRT. Tumor volume was delineated with IMRT planning system and plasma EBV DNA level was quantified by polymerized chain-reaction assay. The effects of tumor volume and EBV DNA level, either alone or in combination, on 5-year overall survival (OS) were cross-compared.
  
  
  
  The 5-year OS in patients with gross tumor volume of nasopharynx (GTVnx)⩽20cc and >20cc was significantly different (P=0.001). The 5-year OS in patients with EBV DNA <6800copies/mL and ⩾6800copies/mL was also significantly different (P<0.001). Based on the combination of GTVnx with EBV DNA, the 5-year OS in different subgroups was: low-risk (100%), intermediate-risk (87.8%, 95% CI: 70.6-95.2%) and high-risk (61.3%, 95% CI: 47.9-72.2%). Patients with small tumor volume and high EBV DNA level had a worse prognosis than those with large tumor and low EBV DNA level. Patients with low EBV DNA levels, and either small or large tumor volumes, had favorable prognosis. According to small or large tumor volume, patients with high EBV DNA level were divided into intermediaterisk and high-risk subgroups.
  
  
  
  Combining tumor volume with pre-treatment plasma EBV DNA level altered survival-risk definition for subgroups of NPC patients and this combination, more than individual factors alone, improved the accuracy of prognostic evaluation.
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060, China; Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Lixia
authors.initials: L
authors.lastname: Lu
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou 510080, China.
authors.forename: Jiaxin
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060, China; Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Wenqiong
authors.initials: W
authors.lastname: Xue
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060, China; Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Han
authors.affiliation: Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China; Department of Molecular Diagnostics, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: Tang
authors.initials: T
authors.lastname: Tao
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060, China; Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chang
authors.affiliation: Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Jia
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060, China; Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China. Electronic address: lutx@sysucc.org.cn.
authors.forename: Taixiang
authors.initials: T
authors.lastname: Lu
mesh_terms: D000328:Adult; D004279:DNA, Viral / Q000235:genetics*; D005260:Female; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D008297:Male; D009303:Nasopharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000821:virology; D011379:Prognosis; D011446:Prospective Studies; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D016019:Survival Analysis
chemical_list: D004279:DNA, Viral
keywords: Epstein-Barr virus DNA; Intensity-modulated radiotherapy; Prognosis; Tumor volume