title: Lymph node ratio predicts local recurrence for periampullary tumours.
abstract: BACKGROUND
  To better define the prognostic role of nodal disease, evaluation of metastatic lymph node ratio (MLR) has been performed, and this method has recently gained prominence in various gastrointestinal cancers. The present study attempts to identify prognostic factors and evaluate the independent prognostic influence of MLR in patients who have undergone curative pancreaticoduodenectomy.
  
  
  METHODS
  In our institution within the study period, 111 patients received curative pancreaticoduodenectomy for periampullary cancers. Clinicopathologic data were collected and MLR was calculated for each of the patients. Patients were then divided into four groups based on MLR value: MLR 1 = 0; MLR 2 = 0.01-0.2; MLR 3 0.21-0.4; and MLR 4 >0.4.
  
  
  RESULTS
  Increasing MLR correlates with high recurrence rate and lower overall survival (OS) with significance (P < 0.001, P < 0.001). The recurrent group showed significantly lower OS than the non-recurrent group (P < 0.001). In the multivariate analysis for recurrence, MLR was identified as the only independent prognostic factor (P < 0.001).
  
  
  CONCLUSIONS
  The simple and easily obtainable MLR is well qualified as a prognostic factor in patients who undergo curatively radical resection for periampullary cancer. Furthermore, MLR can overcome the limitations of evaluation of lymph nodes status, allowing it to be used as a potential prognostic factor.
authors.affiliation: Department of Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Sung Ryol
authors.initials: SR
authors.lastname: Lee
authors.forename: Hyung Ook
authors.initials: HO
authors.lastname: Kim
authors.forename: Yong Lai
authors.initials: YL
authors.lastname: Park
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Shin
mesh_terms: D014670:Ampulla of Vater; D003138:Common Bile Duct Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D005544:Forecasting; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local; D016577:Pancreaticoduodenectomy; D011379:Prognosis
keywords: curative pancreaticoduodenectomy; metastatic lymph node ratio; periampullary cancer; prognostic factor