title: Molecular subtype classification is a determinant of non-sentinel lymph node metastasis in breast cancer patients with positive sentinel lymph nodes.
abstract: BACKGROUND
  Previous studies suggested that the molecular subtypes were strongly associated with sentinel lymph node (SLN) status. The purpose of this study was to determine whether molecular subtype classification was associated with non-sentinel lymph nodes (NSLN) metastasis in patients with a positive SLN.
  
  
  RESULTS
  Between January 2001 and March 2011, a total of 130 patients with a positive SLN were recruited. All these patients underwent a complete axillary lymph node dissection. The univariate and multivariate analyses of NSLN metastasis were performed. In univariate and multivariate analyses, large tumor size, macrometastasis and high tumor grade were all significant risk factors of NSLN metastasis in patients with a positive SLN. In univariate analysis, luminal B subgroup showed higher rate of NSLN metastasis than other subgroup (P = 0.027). When other variables were adjusted in multivariate analysis, the molecular subtype classification was a determinant of NSLN metastasis. Relative to triple negative subgroup, both luminal A (P = 0.047) and luminal B (P = 0.010) subgroups showed a higher risk of NSLN metastasis. Otherwise, HER2 over-expression subgroup did not have a higher risk than triple negative subgroup (P = 0.183). The area under the curve (AUC) value was 0.8095 for the Cambridge model. When molecular subtype classification was added to the Cambridge model, the AUC value was 0.8475.
  
  
  CONCLUSIONS
  Except for other factors, molecular subtype classification was a determinant of NSLN metastasis in patients with a positive SLN. The predictive accuracy of mathematical models including molecular subtype should be determined in the future.
authors.affiliation: Department of Breast Surgery, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Zhou
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: He
authors.forename: Jialei
authors.initials: J
authors.lastname: Xue
authors.forename: Minghai
authors.initials: M
authors.lastname: Wang
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zha
authors.forename: Lijun
authors.initials: L
authors.lastname: Ling
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.forename: Shui
authors.initials: S
authors.lastname: Wang
authors.forename: Xiaoan
authors.initials: X
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001943:Breast Neoplasms / Q000145:classification / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D010634:Phenobarbital / Q000378:metabolism; D012372:ROC Curve; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D012189:Retrospective Studies; D012307:Risk Factors; D021701:Sentinel Lymph Node Biopsy
chemical_list: D010634:Phenobarbital; D018719:Erb-b2 Receptor Tyrosine Kinases