title: Lymph node ratio is an independent prognostic factor after resection of periampullary malignancies: data from a tertiary referral center in the middle East.
abstract: OBJECTIVE
  The prognostic impact of nodal involvement in resected pancreatic carcinoma and biliary malignancy has been relatively well established. It has been suggested that lymph node ratio (LNR) may be a more informative way of stratifying patients with node positive disease. Our retrospective review aimed to investigate the significance of such variables and test for independent prognostic factors for survival.
  
  
  METHODS
  One hundred eighty-three pancreatic and periampullary malignancy cases were registered at the American University of Beirut Medical Center from 1990 to 2004. Of those, 80 had complete data on lymph node status. We analyzed the impact of the number of lymph nodes resected, the number of positive lymph nodes retrieved and LNR using Kaplan-Meier and Cox proportional hazard models. The measured outcome in the KM model was the survival probability at 1, 3, and 5 years while the Cox model was used to measure the hazard ratio (HR) of the previously identified predictors on survival.
  
  
  RESULTS
  For the 80 patients included in this analysis, overall survival rates were 65% (54 to 78), 32% (18 to 47), and 21% (8 to 34) were alive at 1, 3, and 5 years, respectively. The median number of resected lymph nodes was 9. In the node positive patients, those who had >12 nodes examined were found to have a significantly better survival (HR=0.24; P=0.013). On multivariate analysis, our model showed the following factors to be significant: age 60 years or older (HR=5.92; P=0.018), poorly differentiated tumors (HR=21.87; P=0.018), number of lymph nodes examined <12 LN (HR=6.77; P=0.022), 3 or more metastatic LN (HR=7.21; P=0.028), and LNR≥0.2 (HR=7.12; P=0.007).
  
  
  CONCLUSIONS
  After pancreaticodudonectomy for adenocarcinoma of the pancreas and biliary malignancies, ratio-based lymph node staging is an independent and powerful prognostic factor.
authors.affiliation: *Department of Internal Medicine, Division of Hematology and Oncology †Liver Transplantation and Hepatopancreaticobiliary Surgery, Department of General Surgery ‡Department of Internal Medicine, Division of Gastroenterology, American University of Beirut, Beirut §Lebanese American University, School of Pharmacy, Byblos, Lebanon ∥Memorial Sloan-Kettering Cancer Center, Section of Gastrointestinal Oncology, New York, NY.
authors.forename: Ali I
authors.initials: AI
authors.lastname: Shamseddine
authors.forename: Deborah
authors.initials: D
authors.lastname: Mukherji
authors.forename: Christian
authors.initials: C
authors.lastname: Melki
authors.forename: Elias
authors.initials: E
authors.lastname: Elias
authors.forename: Mohammad
authors.initials: M
authors.lastname: Eloubeidi
authors.forename: Hani
authors.initials: H
authors.lastname: Dimassi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Khalife
authors.forename: Ghassan
authors.initials: G
authors.lastname: Abou-Alfa
authors.forename: Eileen
authors.initials: E
authors.lastname: O'Reilly
authors.forename: Walid
authors.initials: W
authors.lastname: Faraj
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007861:Lebanon; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D016577:Pancreaticoduodenectomy; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D062606:Tertiary Care Centers