title: Sentinel nodes in breast cancer: relevance of axillary level II nodes and optimal number of nodes that need to be removed.
abstract: BACKGROUND
  In some patients, the radiocolloid used to perform sentinel lymph node biopsy (SLNB) for breast cancer appears in a number of lymph nodes and in different levels of the axilla. Most positive sentinel lymph node specimens (SLNSs) removed during SLNB are identified in level I of the axilla and within the first 4 SLNSs. Our objective was to verify the staging accuracy of harvesting only the first 4 SLNSs and to determine the relevance of SLNSs that reside in level II of the axilla.
  
  
  METHODS
  A prospective database documenting the method of identification, radioisotope count, order of retrieval, and axillary level of SLNSs from 893 SLNBs was analyzed.
  
  
  RESULTS
  A median of 2 SLNSs (range 1-9) were removed per patient. More than 4 SLNSs were found in 8.0%. All SLNSs harboring the largest nodal metastases were identified within the first 4 harvested. Twenty-one percent (184 of 870) of patients had level II SLNSs; 4.9% (9 of 184) were positive. When SLNSs were positive in both levels I and II, the nodal metastases were always of greater or equal size in the level I nodes. Only one patient (0.5%) had a positive level II SLNS macrometastasis (> 2 mm, pN1), with a negative level I SLNS, but it was the hottest node and was removed first.
  
  
  CONCLUSIONS
  Removal of more than the first 4 hottest SLNSs does not improve staging accuracy. Level II nodes can be ignored if a hotter level I SLNS is first identified.
authors.affiliation: Department of Surgical Oncology, Princess Margaret Hospital, University Health Network and University of Toronto, Toronto, Ontario, Canada. boileaujf@hotmail.com
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Boileau
authors.forename: Alexandra
authors.initials: A
authors.lastname: Easson
authors.forename: Jaime M
authors.initials: JM
authors.lastname: Escallon
authors.forename: Wey L
authors.initials: WL
authors.lastname: Leong
authors.forename: Michael
authors.initials: M
authors.lastname: Reedijk
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Youngson
authors.forename: David R
authors.initials: DR
authors.lastname: McCready
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D021701:Sentinel Lymph Node Biopsy