title: Quantitation of sentinel node metastatic burden and Her-2/neu over-expression accurately predicts residual axillary nodal involvement and extranodal disease in breast cancer.
abstract: BACKGROUND
  Recent literature has suggested that completion axillary lymph node dissection (ALND) in breast carcinoma patients with positive SLN may not be necessary. However, a method for determining the risk of non-SLN or extranodal disease remains to be established.
  
  
  OBJECTIVE
  To determine if pathological variables from primary tumors and sentinel lymph node (SLN) metastases could predict the probability of non-sentinel lymph node (NSLN) metastases and extranodal disease in patients with breast carcinoma and SLN metastases.
  
  
  METHODS
  84 women with T1-3 breast cancer and clinically-negative axillae underwent completion ALND. Maximum diameter and width of SLN metastases were measured to calculate metastatic area. When multiple SLNs contained metastases, areas were summed to calculate the Total Metastatic Area (TMA). Multiple linear regression models were used to identify predictive factors.
  
  
  RESULTS
  Her-2/neu over-expression increased the odds of NSLN metastases (OR 4.3, p = 0.01) and extranodal disease (OR 7.9, p < 0.001). Independent SLN predictors were ≥1 positive SLN (OR, 7.35), maximum diameter and area of SLN metastases (OR 2.26, 1.85 respectively) and TMA (OR, 2.12). Maximum metastatic diameter/SLN diameter (OR 3.71, p = 0.04) and the area of metastases/SLN area (OR 3.4, p = 0.04) were predictive. For every 1 mm increase in diameter of SLN metastases, the odds of NSLN extranodal disease increased by 8.5% (p = 0.02). TMA >0.40 cm(2) was an independent predictor for NSLN metastases and extranodal disease.
  
  
  CONCLUSIONS
  Her-2/neu over-expression and parameters assessing metastatic burden in the SLN, particularly TMA, predicted the presence of NSLN involvement and extranodal disease in patients with breast carcinoma and SLN metastases.
authors.affiliation: Department of Surgery, UC Davis Health System, 2315 Stockton Blvd., Sacramento, CA 95817, USA. andrew.chae@ucdmc.ucdavis.edu
authors.forename: A W
authors.initials: AW
authors.lastname: Chae
authors.forename: K M
authors.initials: KM
authors.lastname: Vandewalker
authors.forename: Y J
authors.initials: YJ
authors.lastname: Li
authors.forename: L A
authors.initials: LA
authors.lastname: Beckett
authors.forename: R
authors.initials: R
authors.lastname: Ramsamooj
authors.forename: R J
authors.initials: RJ
authors.lastname: Bold
authors.forename: V P
authors.initials: VP
authors.lastname: Khatri
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000737:chemistry / Q000473:pathology; D018275:Carcinoma, Lobular / Q000737:chemistry / Q000473:pathology; D015986:Confounding Factors, Epidemiologic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D016014:Linear Models; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D021701:Sentinel Lymph Node Biopsy; D015854:Up-Regulation
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human