title: Value of preoperative ultrasound-guided axillary lymph node biopsy for preventing completion axillary lymph node dissection in breast cancer: a systematic review and meta-analysis.
abstract: OBJECTIVE
  This meta-analysis was designed to evaluate the utility of preoperative axillary ultrasound combined with US-guided lymph node biopsy if indicated (AUS ± biopsy), in terms of staging the axilla and preventing two-step axillary surgery in the form of sentinel node biopsy (SNB) followed by completion axillary lymph node (ALN) dissection.
  
  
  METHODS
  We systematically searched electronic databases for studies that addressed preoperative assessment of ALN status by AUS ± biopsy. A pooled estimate was calculated for the false-negative rate (FNR) of AUS ± biopsy (defined as the proportion of women with a negative AUS ± biopsy result subsequently proven to have a positive axilla) and sensitivity (defined as the proportion of women with a positive AUS ± biopsy result among all women with a tumor positive axilla).
  
  
  RESULTS
  The pooled FNR was 25 % (95 % confidence interval [CI] = 24-27) and the pooled sensitivity was 50 % (95 % CI = 43-57). There was substantial heterogeneity across studies for both FNR (I (2) = 69.42) and sensitivity (I (2) = 93.25), which was not explained by between-study differences in biopsy technique, mean/median tumor size, biopsy indication, or study design. Sensitivity was increased in studies with a high prevalence of ALN metastases.
  
  
  CONCLUSIONS
  Preoperative axillary ultrasound-guided biopsy is a useful step in the process of axillary staging. Approximately 50 % of women with axillary involvement can be identified preoperatively. Still, one in four women with an ultrasound-guided biopsy-"proven" negative axilla has a positive SNB.
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands, s.c.e.diepstraten@umcutrecht.nl.
authors.forename: Suzanne C E
authors.initials: SC
authors.lastname: Diepstraten
authors.forename: Ali R
authors.initials: AR
authors.lastname: Sever
authors.forename: Constantinus F M
authors.initials: CF
authors.lastname: Buckens
authors.forename: Wouter B
authors.initials: WB
authors.lastname: Veldhuis
authors.forename: Thijs
authors.initials: T
authors.lastname: van Dalen
authors.forename: Maurice A A J
authors.initials: MA
authors.lastname: van den Bosch
authors.forename: Willem P Th M
authors.initials: WP
authors.lastname: Mali
authors.forename: Helena M
authors.initials: HM
authors.lastname: Verkooijen
mesh_terms: D001365:Axilla; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis / Q000175:diagnosis; D011300:Preoperative Care; D011379:Prognosis; D021701:Sentinel Lymph Node Biopsy; D018084:Ultrasonography, Interventional