title: Factors affecting metastases to non-sentinel lymph nodes in breast cancer.
abstract: OBJECTIVE
  Because sentinel lymph node (SLN) biopsy for breast cancer has become well established, one of the challenges now is to determine which patients require a completion axillary dissection following a positive SLN biopsy.
  
  
  METHODS
  A prospective database of patients who underwent SLN biopsy for invasive breast cancer from July 1999 to November 2002 (n = 180) was analysed. Fifty four patients (30%) had one or more positive SLN, and all underwent a completion axillary dissection. This subgroup was further analysed to delineate which factors predicted non-SLN metastasis.
  
  
  RESULTS
  Twenty six of the 54 patients with a positive SLN had additional metastases in non-SLNs. Significant variables that predicted non-SLN metastasis included extranodal extension (odds ratio (OR), 17.399; 95% confidence interval (CI), 1.69 to 178.96) and macrometastasis within the SLN (OR, 6.985; 95% CI, 1.291 to 37.785).
  
  
  CONCLUSIONS
  In patients with invasive breast cancer and a positive SLN, extranodal extension or macrometastasis within the SLN were both independent predictors of non-SLN involvement.
authors.affiliation: Department of Surgery, St Vincent's University Hospital and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland.
authors.forename: F J
authors.initials: FJ
authors.lastname: Fleming
authors.forename: D
authors.initials: D
authors.lastname: Kavanagh
authors.forename: T B
authors.initials: TB
authors.lastname: Crotty
authors.forename: C M
authors.initials: CM
authors.lastname: Quinn
authors.forename: E W
authors.initials: EW
authors.lastname: McDermott
authors.forename: N
authors.initials: N
authors.lastname: O'Higgins
authors.forename: A D K
authors.initials: AD
authors.lastname: Hill
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D018579:Patient Selection; D011446:Prospective Studies; D012307:Risk Factors; D021701:Sentinel Lymph Node Biopsy