title: Retropharyngeal lymph node metastasis in nasopharyngeal carcinoma: prognostic value and staging categories.
abstract: OBJECTIVE
  To investigate the incidence, prognostic value, and staging categories of retropharyngeal lymph node (RLN) metastasis in nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  We did a retrospective review of the data from 749 biopsy-proved nonmetastatic NPC patients. All patients had undergone contrast-enhanced computed tomography and had radiotherapy as their primary treatment.
  
  
  RESULTS
  The incidence of RLN metastasis was 51.5%. After adjusting for tumor (T) and node (N) classifications, a borderline significant difference of distant metastasis-free survival (DMFS) rates was observed between patients with or without RLN metastasis. In N(0) disease, the presence of RLN metastasis was a significant independent predictor for overall survival (OS), loco-regional relapse-free survival, and DMFS in multivariate Cox modeling analysis. No significant difference was observed in all end points between patients with unilateral and bilateral RLN metastasis. The hazard ratios of death and distant failure for N(0) with RLN metastasis were similar to N(1). The survival curve of OS and DMFS for N(0) disease with RLN metastasis had approximated that of N(1) disease. The survival curve of OS for T(1) disease with RLN metastasis was approximately the same as T(2) disease. However, the survival curve of DMFS for T(1) disease with RLN metastasis was approximately the same as in T(3) disease.
  
  
  CONCLUSIONS
  RLN metastasis has a tendency to affect the DMFS rates of patients with NPC. Retropharyngeal node involvement has a negative effect on the prognosis of N(0) disease. RLN metastasis should be classified as N(1).
authors.affiliation: State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center, Sun Yat-sen University, Guangzhou, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.forename: Lizhi
authors.initials: L
authors.lastname: Liu
authors.forename: Linglong
authors.initials: L
authors.lastname: Tang
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Zong
authors.forename: Aihua
authors.initials: A
authors.lastname: Lin
authors.forename: Taixiang
authors.initials: T
authors.lastname: Lu
authors.forename: Nianji
authors.initials: N
authors.lastname: Cui
authors.forename: Chunyan
authors.initials: C
authors.lastname: Cui
authors.forename: Li
authors.initials: L
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology* / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed