title: Analysis of risk factors for skip lymphatic metastasis and their prognostic value in operated N2 non-small-cell lung carcinoma.
abstract: BACKGROUND
  The aim of this study is to report a series and to analyze risk factors for skip lymphatic metastasis an their prognostic value in operated N2 non-small-cell lung carcinoma.
  
  
  METHODS
  From 1997 to 2002, 142 patients classified pN2 were included in the study. Tumours were classified according to the TNM classification. Skips metastases were defined by the cases of N2 disease without lobar and interlobar and hilar lymph node involvement. A skip (+) and a skip (-) group were defined. Characteristics of tumours, ganglionar involvement and survival were analysed in both groups.
  
  
  RESULTS
  Forty-two patients fulfilled the criteria for skip metastasis. The average number of mediastinal lymph nodes resected by patient was similar in both groups, whereas more intrapulmonary nodes were dissected in the skip (-) group (4.7 +/- 3 vs 3 +/- 3; p < 0.002). The ratio of involved to resected lymph nodes was 0.47 +/- 0.27 in the skip (-) group vs 0.23 +/- 0.20 in the skip (+) group (p < 0.0001). In the skip (+) group, 85% of the patients presenting with a right upper lobe tumour had involvement of the superior mediastinal lymph nodes against 40% in the skip (-) group. The 5-year survival rate was 48% in the skip (-) group vs 37% in the skip (+) group (p = 0.49). In multivariate analysis, incomplete resection, tumour size, extended resection and pT were significant prognostic factors.
  
  
  CONCLUSIONS
  Skip metastasis are frequent in non-small-cell lung cancer and complete dissection of hilar and mediastinal lymph nodes should remain the surgical standard procedure for this disease. However, skip metastasis are not an independent prognostic factor in survival.
authors.affiliation: Department of General Thoracic Surgery, Hôpital Universitaire du Bocage, Dijon, France.
authors.forename: L
authors.initials: L
authors.lastname: Benoit
authors.forename: A
authors.initials: A
authors.lastname: Anusca
authors.forename: P
authors.initials: P
authors.lastname: Ortega-Deballon
authors.forename: N
authors.initials: N
authors.lastname: Cheynel
authors.forename: A
authors.initials: A
authors.lastname: Bernard
authors.forename: J P
authors.initials: JP
authors.lastname: Favre
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery*; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008482:Mediastinum; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D018365:Neoplasm, Residual / Q000473:pathology; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome