title: Axillary recurrence after a tumour-negative sentinel node biopsy in breast cancer patients: A systematic review and meta-analysis of the literature.
abstract: BACKGROUND
  Sentinel node biopsy became the standard of care before consensus on the technique was reached and without randomized studies having shown a similar or decreased axillary recurrence rate. The purpose of this study was to evaluate studies reporting on patients with a negative sentinel node biopsy.
  
  
  METHODS
  We performed a systematic review and meta-analysis of the literature for studies concerning clinically node-negative breast cancer patients with a tumour-negative sentinel node biopsy and no subsequent axillary node dissection. The axillary recurrence rate was determined, as well as the sensitivity of the sentinel node procedure and the differences in lymphatic mapping techniques.
  
  
  RESULTS
  Forty-eight studies concerning 14 959 sentinel node-negative breast cancer patients followed for a median of 34 months were selected. Sixty-seven patients developed an axillary recurrence, resulting in a recurrence rate of 0.3%. The sensitivity of the sentinel node biopsy was 100%. Uni- and multivariable variable analyses showed that the lowest recurrence rates were reported in studies performed in cancer centres, in studies that described the use of (99m)Tc-sulphur colloid, and also when investigators used the superficial injection technique or evaluated the harvested sentinel nodes with haematoxylin-eosin and immunohistochemistry staining (p<0.01).
  
  
  CONCLUSIONS
  In this systematic literature review, the axillary recurrence rate in sentinel node-negative patients is 0.3%, which is well within the desired range. The median sensitivity of the procedure appears to be as high as 100%. The recurrence rate is influenced by the differences in the lymphatic mapping technique.
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands. i.vd.ploeg@nki.nl
authors.forename: I M C
authors.initials: IM
authors.lastname: van der Ploeg
authors.forename: O E
authors.initials: OE
authors.lastname: Nieweg
authors.forename: M C
authors.initials: MC
authors.lastname: van Rijk
authors.forename: R A
authors.initials: RA
authors.lastname: Valdés Olmos
authors.forename: B B R
authors.initials: BB
authors.lastname: Kroon
mesh_terms: D001365:Axilla; D001943:Breast Neoplasms / Q000556:secondary / Q000601:surgery*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D015994:Incidence; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D011379:Prognosis; D021701:Sentinel Lymph Node Biopsy / Q000009:adverse effects*