title: Meta-analysis of predictive factors for non-sentinel lymph node metastases in breast cancer patients with a positive SLN.
abstract: OBJECTIVE
  A meta-analysis was performed to identify the clinicopathological variables most predictive of non-sentinel node (NSN) metastases when the sentinel node is positive.
  
  
  METHODS
  A Medline search was conducted that ultimately identified 56 candidate studies. Original data were abstracted from each study and used to calculate odds ratios. The random-effects model was used to combine odds ratios to determine the strength of the associations.
  
  
  RESULTS
  The 8 individual characteristics found to be significantly associated with the highest likelihood (odds ratio >2) of NSN metastases are SLN metastases >2mm in size, extracapsular extension in the SLN, >1 positive SLN, ≤1 negative SLN, tumour size >2cm, ratio of positive sentinel nodes >50% and lymphovascular invasion in the primary tumour. The histological method of detection, which is associated with the size of metastases, had a correspondingly high odds ratio.
  
  
  CONCLUSIONS
  We identified 8 factors predictive of NSN metastases that should be recorded and evaluated routinely in SLN databases. These factors should be included in a predictive model that is generally applicable among different populations.
authors.affiliation: Department of Surgery, Gelderse Vallei Hospital, 6716 RP Ede, The Netherlands. rfdvanlaparra@tiscali.nl
authors.forename: R F D
authors.initials: RF
authors.lastname: van la Parra
authors.forename: P G M
authors.initials: PG
authors.lastname: Peer
authors.forename: M F
authors.initials: MF
authors.lastname: Ernst
authors.forename: K
authors.initials: K
authors.lastname: Bosscha
mesh_terms: D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000175:diagnosis; D016239:MEDLINE; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D021701:Sentinel Lymph Node Biopsy