title: The ratio of metastatic to examined lymph nodes is a powerful independent prognostic factor in rectal cancer.
abstract: OBJECTIVE
  The aim of the study was to evaluate the prognostic value of the ratio of metastatic to examined lymph nodes (LNR) in patients with rectal cancer.
  
  
  BACKGROUND
  Lymph nodes ratio (LNR) has been shown to have prognostic value in patients with colon cancer. The impact of LNR on disease-free and overall survival in patients with rectal cancer is unknown.
  
  
  METHODS
  From 1998 to 2004, 307 patients underwent rectal resection for adenocarcinoma. The relationships between overall and disease-free survival at 3 years and 15 variables, including the presence or absence of metastatic lymph nodes, the total number of lymph nodes examined, and LNR, were analyzed by multivariate analysis. Patients were then assigned to 4 groups based on LNR: LNR = 0 (N0 patients), LNR = 0.01 to 0.07, LNR >0.07 to 0.2, LNR >0.2.
  
  
  RESULTS
  The mean number of lymph nodes examined was 22 +/- 12. In the multivariate analysis, LNR was a significant prognostic factor for both disease-free (P = 0.006) and overall survival (P = 0.0003), whereas the presence or absence of metastatic lymph nodes was not. LNR remained a significant prognostic factor in the 59 patients in whom fewer than 12 lymph nodes were examined (P = 0.0058). According to LNR values, disease-free and overall survival decreased significantly with increasing LNR (P < 0.001).
  
  
  CONCLUSIONS
  LNR is the most significant prognostic factor for both overall and disease-free survival in patients with rectal cancer, even in patients with fewer than 12 lymph nodes examined.
authors.affiliation: Department of Surgery, Assistance-Publique-Hôpitaux de Paris, Hôpital Ambroise Paré, Boulogne, Boulogne, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Peschaud
authors.forename: Peschaud
authors.initials: P
authors.lastname: Frédérique
authors.forename: Stéphane
authors.initials: S
authors.lastname: Benoist
authors.forename: Benoist
authors.initials: B
authors.lastname: Stéphane
authors.forename: Catherine
authors.initials: C
authors.lastname: Julié
authors.forename: Julié
authors.initials: J
authors.lastname: Catherine
authors.forename: Alain
authors.initials: A
authors.lastname: Beauchet
authors.forename: Beauchet
authors.initials: B
authors.lastname: Alain
authors.forename: Christophe
authors.initials: C
authors.lastname: Penna
authors.forename: Penna
authors.initials: P
authors.lastname: Christophe
authors.forename: Philippe
authors.initials: P
authors.lastname: Rougier
authors.forename: Rougier
authors.initials: R
authors.lastname: Philippe
authors.forename: Bernard
authors.initials: B
authors.lastname: Nordlinger
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology*; D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology*; D016019:Survival Analysis