title: Independent predictive value of the overall number of metastatic N1 and N2 stations in lung cancer.
abstract: OBJECTIVE
  The number of metastatic N2 stations is a known prognostic factor in patients with non-small-cell lung cancer (NSCLC). However, involvement of N1 stations as well as that of N2 stations seems to be important in the prognosis of these patients. We therefore attempt to clarify the significance of the total number of metastatic stations in pathologic N1 and N2 NSCLCs.
  
  
  METHODS
  Patients with either pathologic N1 (n = 51) or N2 (n = 96) NSCLC who had undergone major pulmonary resection with complete mediastinal dissection were included in this retrospective study. All positive nodes were characterized by location according to the TNM classification system. The hilar station was included with the N2 stations.
  
  
  RESULTS
  The total number of metastatic stations in patients with N2 disease ranged from 1 to 8 (average 2.5), whereas that in patients with N1 disease ranged from 1 to 3 (average 1.2). The incidence of multiple-station metastasis (> or = 3 metastatic stations) among N2 patients (35%) was significantly higher than that among N1 patients (2%) (p < 0.001). Multivariate analysis of survival showed pathologic N1 status (relative risk = 0.443, p = 0.013) and < or = 2 metastatic stations (relative risk = 0.515, p = 0.020) to be significant and independent prognostic factors. Age, sex, cell type, resected lobe, and pathological T status were statistically insignificant determinates of survival.
  
  
  CONCLUSIONS
  The total number of metastatic stations (< or = 2 vs > or = 3) is an independent prognostic indicator in patients with completely resected pathologic N1 or N2 NSCLC. The number of metastatic stations will be useful as a stratification factor in prospective clinical trials of these patients.
authors.affiliation: First Department of Surgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ueda
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kaneda
authors.forename: Hisashi
authors.initials: H
authors.lastname: Sakano
authors.forename: Toshiki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Masatarou
authors.initials: M
authors.lastname: Hayashi
authors.forename: Tao-Sheng
authors.initials: TS
authors.lastname: Li
authors.forename: Kimikazu
authors.initials: K
authors.lastname: Hamano
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology* / Q000556:secondary*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology* / Q000556:secondary*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D016019:Survival Analysis