title: Risk stratification based on change in plasma Epstein-Barr virus DNA load after treatment in nasopharyngeal carcinoma.
abstract: BACKGROUND
  Nasopharyngeal carcinoma is associated with Epstein-Barr virus (EBV). The current study investigated change in the plasma EBV DNA load in the first 3 months after treatment and its clinical significance in NPC.
  
  
  METHODS
  A total of 273 patients with non-metastatic, histologically-proven NPC treated with radiotherapy or chemoradiotherapy were retrospectively reviewed.
  
  
  RESULTS
  EBV DNA was detectable in 19/273 (7.0%) patients at the end of therapy (end-DNA). Three months later, 16/273 (5.9%) patients had detectable EBV DNA (3-month-DNA). To investigate risk stratified by the pattern of change in post-treatment EBV-DNA, we divided patients into four subgroups: Group 1, undetectable end-DNA and 3-month-DNA (n = 244); Group 2, detectable end-DNA and undetectable 3-month-DNA (n = 13); Group 3, undetectable end-DNA and detectable 3-month-DNA (n = 7); and Group 4, detectable end-DNA and 3-month-DNA (n = 2). Patients with delayed remission of EBV DNA after treatment (Group 2) had significantly poorer 3-year DFS (48.6% vs. 89.7%, P < 0.001), DMFS (48.6% vs. 94.6%, P < 0.001) and OS (91.7% vs. 97.5%, P < 0.001) than those with persistently undetectable EBV DNA post-treatment (Group 1). Five of the seven patients with re-emergent EBV DNA (Group 3) and both patients with persistent EBV DNA post-treatment (Group 4) developed disease failure.
  
  
  CONCLUSIONS
  Plasma EBV DNA load continues to change during the first 3 months after treatment. The pattern of change in EBV DNA load post-treatment could help identify patients with different prognoses.
authors: Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Yuan
authors: Y
authors: Zhang
authors: Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Wen-Fei
authors: WF
authors: Li
authors: Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Yan-Ping
authors: YP
authors: Mao
authors: Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Rui
authors: R
authors: Guo
authors: Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Ling-Long
authors: LL
authors: Tang
authors: Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Hao
authors: H
authors: Peng
authors: Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Ying
authors: Y
authors: Sun
authors: Department of Cancer Prevention Research, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Qing
authors: Q
authors: Liu
authors: Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Lei
authors: L
authors: Chen
authors: Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, People's Republic of China.
authors: Jun
authors: J
authors: Ma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma; D004279:DNA, Viral / Q000097:blood*; D018572:Disease-Free Survival; D020031:Epstein-Barr Virus Infections / Q000821:virology; D005260:Female; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000401:mortality* / Q000628:therapy* / Q000821:virology; D012189:Retrospective Studies; D012306:Risk; D019562:Viral Load; D055815:Young Adult
chemical_list: D004279:DNA, Viral
keywords: DNA; Epstein-Barr virus; biological; nasopharyngeal neoplasms; tumor markers