title: Cervical nodal necrosis is an independent survival predictor in nasopharyngeal carcinoma: an observational cohort study.
abstract: OBJECTIVE
  Most nasopharyngeal carcinoma (NPC) patients present with locoregionally advanced disease at the time of diagnosis; however, there is a lack of consensus on specific prognostic factors potentially improving overall survival, especially in late-stage disease. Herein, we conducted a retrospective study to evaluate various potential prognostic factors in order to provide useful information for clinical treatment of T3/T4-stage NPC.
  
  
  METHODS
  A total of 189 previously untreated NPC patients were enrolled in the current study. All patients received intensity-modulated radiotherapy. Survival, death, relapse-free survival (both local and regional), and metastasis were recorded during follow-up. Factors affecting patient survival were assessed by using univariate and multivariate analyses.
  
  
  RESULTS
  The median follow-up time was 69 months. The 5-year local-regional recurrence-free survival, distant metastasis-free survival, progression-free survival (PFS), and overall survival (OS) of the entire group were 89.8%, 71.5%, 66.3%, and 68.9%, respectively. Univariate analysis revealed significant differences in the 5-year PFS (58.5% vs 72.5%,P=0.015) and OS (59.5% vs 75.8%,P=0.033) rates of patients with and without cervical nodal necrosis (CNN). Subgroup analyses revealed that CNN was associated with poorer distant metastasis-free survival and PFS among patients with N2 stage (P=0.046 andP=0.005) and with poorer PFS among patients with T3 or III stage (allP=0.022). Multivariate analysis revealed CNN to be an independent prognostic factor for PFS and OS (PFS: adjusted hazard ratio, 1.860; 95% CI: 1.134-3.051;P=0.014; OS: adjusted hazard ratio, 1.754; 95% CI: 1.061-2.899;P=0.028).
  
  
  CONCLUSIONS
  CNN is a potential independent negative prognostic factor in NPC patients. Our results suggest that stratification of NPC patients based on their CNN status should be considered as part of NPC disease management.
authors.affiliation: Department of Radiation Oncology.
authors.forename: Yangkun
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Department of Radiology, Sichuan Cancer Hospital, Chengdu.
authors.forename: Jing
authors.initials: J
authors.lastname: Ren
authors.affiliation: Department of Radiology, Sichuan Cancer Hospital, Chengdu.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhou
authors.affiliation: Department of Radiation Oncology, Zigong No 4 People's Hospital of Sichuan Province, Zigong, Sichuan, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Radiation Oncology.
authors.forename: Guangquan
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology.
authors.forename: Jinyi
authors.initials: J
authors.lastname: Lang
keywords: cervical nodal necrosis; chemotherapy; intensity-modulated radiotherapy; nasopharyngeal carcinoma; prognostic factor