title: [Prognostic value of the number of lymph nodes retrieved after selective neck dissection in hypopharyngeal squamous carcinoma].
abstract: OBJECTIVE
  To discuss the influence of the number of lymph nodes retrieved after selective neck dissection on the prognosis of hypopharyngeal squamous carcinoma.
  
  
  METHODS
  A retrospective review was performed on 96 patients with hypopharyngeal squamous carcinoma between January 1995 and December 2009, and all cases were accepted initial treatment for selective neck dissection. t test was used for analysis of normally distributed and Mann-Whitney U test for non-normally distributed continuous data in two groups. Comparisons were made by χ(2) analysis for categorical variables. Overall survival, disease-free survival and neck-control rate were calculated by the Kaplan-Meier method.
  
  
  RESULTS
  The mean number of lymph nodes retrieved in all patients with hypopharyngeal squamous carcinoma was 19.0 ± 11.3. Preoperative radiotherapy significantly decreased the number of retrieved lymph nodes and positive lymph nodes (t = -4.45, P < 0.001 and U = 568, P < 0.001, respectively). The number of nodes retrieved ≤ 15 was associated with 3-year overall survival of 37.7% compared with 71.3% in those with nodes retrieved > 15 by using Kaplan-Meier analysis (χ(2) = 8.214, P < 0.01). 3-year disease-free survival rates were 34.8% in those with ≤ 15 nodes and 61.7% in patients with > 15 nodes (χ(2) = 7.345, P < 0.01). The 3-year neck-control rates were 97.4% and 76.7% (> 15 nodes vs. ≤ 15 nodes;χ(2) = 5.539, P < 0.05), respectively. After adjusting for the effect of T stage and N stage on multivariate analysis, the number of nodes retrieved > 15 was an independent prognostic factor in patients undergoing selective neck dissection for hypopharyngeal squamous carcinoma (P < 0.05).
  
  
  CONCLUSIONS
  The number of lymph nodes retrieved is a valuable prognostic factor in patients received selective neck dissection for hypopharyngeal squamous carcinoma. These results suggest that at least 15 nodes should be examined in this setting.
authors.affiliation: Department of Head and Neck Surgery, Cancer Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100021, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Yu
authors.forename: Xiao-lei
authors.initials: XL
authors.lastname: Wang
authors.forename: Zhen-gang
authors.initials: ZG
authors.lastname: Xu
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000473:pathology*; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000175:diagnosis / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection / Q000379:methods*; D011379:Prognosis; D012189:Retrospective Studies; D000077195:Squamous Cell Carcinoma of Head and Neck