title: Long-term survival of patients with pN2 lung cancer according to the pattern of lymphatic spread.
abstract: BACKGROUND
  N2 involvement has dramatic consequences on the prognosis and management of patients with non-small cell lung cancer (NSCLC). N2-NSCLC may present with or without N1 involvement, constituting non-skip (pN1N2) and skip (pN0N2) diseases, respectively. As the prognostic impact of this subclassification is still a matter of debate, we analyzed the prognosis of pN2 patients according to the pN1-involvement and the number of N2-stations concerned.
  
  
  METHODS
  The medical records of consecutive patients who underwent surgery for pN2-NSCLC in 2 French centers between 1980 and 2009 were prospectively collected and retrospectively reviewed. Patients undergoing induction therapy, exploratory thoracotomy, incomplete mediastinal lymphadenectomy, or incomplete resections were excluded. The prognoses of pN1N2 and pN0N2 patients were first compared, and then deciphered according to the number of N2 stations involved (single-station: 1S, multi-station: 2S).
  
  
  RESULTS
  All together, 871 patients underwent first-line complete surgical resection for pN2-NSCLC during the study period, including 258 pN0N2 (29.6%) and 613 pN1N2 (70.4%) patients. Mean follow-up was 72.8±48 months. Median, 5- and 10-year survivals were, respectively, 30 months, 34%, and 24% for pN0N2 and 20 months, 21%, and 14% for pN1N2 patients (p<0.001). Multivariate analysis revealed 3 different prognostic groups; ie, favorable in pN0N2-1S disease, intermediate in pN0N2-2S and pN1N2-1S diseases, and poor in pN1N2-2S disease (p<0.001).
  
  
  CONCLUSIONS
  Among pN2 patients, the combination of N1 involvement (pN0N2 vs pN1N2) and number of involved N2 stations (1S vs 2S) are independent prognostic factors. These results might be taken into consideration to sub-classify the heterogeneous pN2-NSCLC group of patients.
authors.affiliation: Department of General Thoracic Surgery, Georges Pompidou European Hospital, Descartes University, Paris, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Legras
authors.affiliation: Department of General Thoracic Surgery, Georges Pompidou European Hospital, Descartes University, Paris, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Mordant
authors.affiliation: Department of General Thoracic Surgery, Georges Pompidou European Hospital, Descartes University, Paris, France.
authors.forename: Alex
authors.initials: A
authors.lastname: Arame
authors.affiliation: Department of General Thoracic Surgery, Georges Pompidou European Hospital, Descartes University, Paris, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Foucault
authors.affiliation: Cedar Surgical Centre, Bois Guillaume, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Dujon
authors.affiliation: Department of General Thoracic Surgery, Georges Pompidou European Hospital, Descartes University, Paris, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Le Pimpec Barthes
authors.affiliation: Department of General Thoracic Surgery, Georges Pompidou European Hospital, Descartes University, Paris, France. Electronic address: marc.riquet@egp.aphp.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Riquet
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000473:pathology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D013997:Time Factors