title: Lymph node ratio is more predictive than traditional lymph node stratification in lymph node positive invasive breast cancer.
abstract: OBJECTIVE
  To evaluate the relationships between lymph node ratio (LNR, the ratio of positive lymph nodes in excised axillary lymph nodes) and disease-free survival (DFS) by comparing with traditional absolute positive lymph node number (pN classification) for prediction of breast cancer (BC) progrnosis.
  
  
  METHODS
  We retrospectively reviewed patients who received comprehensive therapy in Department of Breast Surgery, Hubei Cancer Hospital, China from Jan 2002 to Dec 2006 (Group A), and Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, China from Jun 2008 to May 2012 (Group B). Patients were allocated to low-risk (≤0.20), intermediate-risk (> 0.20 but ≤ 0.65), high-risk (>0.65) groups by LNR. The primary endpoint was 5-DFS.
  
  
  RESULTS
  A total of 294 patients were included in our study. LNR was verified as a negative prognostic factor for DFS (P= 0.002 in Group A, P< 0.0001 in Group B). Then we found the effects of pN and LNR delamination on disease-free survival (DFS) had statistical significance (P=0.012 for pN and P=0.031 for LNR stratification in Group A, both of them P<0.001 in Group B). Compared to pN staging, LNR staging displayed superior performance in prognosis, the adjusted hazard ratio of recurrence being 2.07 (95%CI, 1.07 to 4.0) for intermediate risk group (P=0.030) and 2.44 (95%CI, 1.21 to 4.92) for high risk group (P=0.013) in Group A.
  
  
  CONCLUSIONS
  LNR stratification proved an adverse prognostic factor of DFS in lymph nodes positive invasive BC using cut-off values 0.20 and 0.65, and was more predictive than traditional pN classification for 5-DFS.
authors.affiliation: Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China.
authors.forename: Lian-Song
authors.initials: LS
authors.lastname: Bai
authors.forename: Chuang
authors.initials: C
authors.lastname: Chen
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Gong
authors.forename: Wen
authors.initials: W
authors.lastname: Wei
authors.forename: Yi
authors.initials: Y
authors.lastname: Tu
authors.forename: Feng
authors.initials: F
authors.lastname: Yao
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Li
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Wang
authors.forename: Sheng-Rong
authors.initials: SR
authors.lastname: Sun
mesh_terms: D001365:Axilla / Q000473:pathology; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D002681:China; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology*; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D012189:Retrospective Studies; D016019:Survival Analysis