title: Prognostic value of lymph node ratios in node positive rectal cancer treated with preoperative chemoradiation.
abstract: BACKGROUND
  To investigate the impact of the lymph node ratio (LNR) on the prognosis of patients with locally advanced rectal cancer undergoing pre-operative chemoradiation.
  
  
  METHODS
  Clinicopathologic and follow up data of 128 patients with stage III rectal cancer who underwent curative resection from 1996 to 2007 were reviewed. The patients were divided into two groups according to the lymph node ratio: LNR ≤ 0.2 (n=28), and >0.2 (n=100). Kaplan-Meier and the Cox proportional hazard regression models were used to evaluate the prognostic effects according to LNR.
  
  
  RESULTS
  Median numbers of lymph nodes examined and lymph nodes involved by tumour were 10.3 (range 2-28) and 5.8 (range 1-25), respectively, and the median LNR was 0.5 (range, 0-1.6). The 5-year survival rate significantly differed by LNR (≤ 0.2, 69%; >0.2, 19%; Log-rank p value < 0.001). LNR was also a significant prognostic factor of survival adjusted for age, sex, post-operative chemotherapy, total number of examined lymph nodes, metastasis and local recurrence (≤ 0.2, HR=1; >0.2, HR=4.8, 95%CI=2.1-11.1) and a significant predictor of local recurrence and distant metastasis during follow-up independently of total number of examined lymph node.
  
  
  CONCLUSIONS
  Total number of examined lymph nodes and LNR were significant prognostic factors for survival in patients with stage III rectal cancer undergoing pre-operative chemoradiotherapy.
authors.affiliation: Department of Surgical Oncology, Cancer Institute, Tehran University of Medical Science, Tehran, Iran.
authors.forename: Jamal Jafari
authors.initials: JJ
authors.lastname: Nadoshan
authors.forename: Ramesh
authors.initials: R
authors.lastname: Omranipour
authors.forename: Omid
authors.initials: O
authors.lastname: Beiki
authors.forename: Kazem
authors.initials: K
authors.lastname: Zendedel
authors.forename: Abbas
authors.initials: A
authors.lastname: Alibakhshi
authors.forename: Habibollah
authors.initials: H
authors.lastname: Mahmoodzadeh
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000556:secondary / Q000628:therapy; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D059248:Chemoradiotherapy / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000473:pathology; D009367:Neoplasm Staging; D011300:Preoperative Care; D011379:Prognosis; D012004:Rectal Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D015996:Survival Rate; D055815:Young Adult