title: Revisiting the "10% rule" in breast cancer sentinel lymph node biopsy: an approach to minimize the number of sentinel lymph nodes removed.
abstract: BACKGROUND
  Sentinel lymph node (SLN) biopsy (SLNB) is an accurate and proven axillary staging procedure for early breast cancer. The aim of this study was to determine if the "10% rule" is applicable to the performance of SLNB at the investigators' institution and if the criteria used for SLNB at their institution could be refined to minimize the number of SLNs removed.
  
  
  METHODS
  Retrospective analysis was conducted of a prospectively collected breast cancer SLNB database. Standard statistical methods were used for data analysis.
  
  
  RESULTS
  Five hundred nine patients underwent a SLNB for breast cancer over a 5 year period. A mean of 2.5 SLNs were removed per patient. All patients with SLN metastasis were identified within the 1st 4 SLNs removed.
  
  
  CONCLUSIONS
  The "10% rule" is best used as a guide at the investigators' institution. Strict adherence to this rule appears to result in the removal of an excessive number of lymph nodes, which may contribute to excessive health care costs and patient morbidity.
authors.affiliation: Department of Surgical Oncology, British Columbia Cancer Agency, Kelowna, BC, Canada.
authors.forename: Ranjan
authors.initials: R
authors.lastname: Dutta
authors.affiliation: Department of Surgery, Kelowna General Hospital, Kelowna, BC, Canada.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kluftinger
authors.affiliation: Department of Surgery, Kelowna General Hospital, Kelowna, BC, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: MacLeod
authors.affiliation: Department of Radiology, Kelowna General Hospital, Kelowna, BC, Canada.
authors.forename: Gary
authors.initials: G
authors.lastname: Kindrachuk
authors.affiliation: Department of Surgical Oncology, British Columbia Cancer Agency, Kelowna, BC, Canada; Department of Surgery, Kelowna General Hospital, Kelowna, BC, Canada. Electronic address: baliski@me.com.
authors.forename: Chris
authors.initials: C
authors.lastname: Baliski
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy / Q000379:methods / Q000706:statistics & numerical data*