title: Is the one-step nucleic acid amplification assay better for intra-operative assessment of breast sentinel nodes?
abstract: BACKGROUND
  Intra-operative assessment of sentinel lymph nodes in breast cancer offers the opportunity to prevent two-stage surgical procedures. At our institution we employ touch imprint cytology (TIC), which lacks sensitivity. In this study we compare the one-step nucleic acid amplification (OSNA) assay to TIC.
  
  
  METHODS
  Imprints were taken from 63 lymph nodes from 35 patients. The lymph nodes were sectioned at 2-mm intervals and alternate slices submitted for either histology or OSNA assay, with histology as the reference standard.
  
  
  RESULTS
  Seven patients were histologically positive. Nine and five patients were positive by OSNA and TIC, respectively. Sensitivity, specificity, positive and negative predictive value for the OSNA assay were 85.7%, 85.7%, 63.6% and 96.6% and for TIC were 70.0%, 96.6%, 87.5% and 90.3%.
  
  
  CONCLUSIONS
  In this study OSNA had a higher sensitivity than TIC. Fewer patients assessed by the OSNA assay would have required a two-stage procedure. The OSNA assay appears to be a highly cost-effective method for providing rapid and reliable intra-operative assessment of sentinel lymph nodes.
authors.affiliation: Royal Brisbane and Women's Hospital, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Bettington
authors.forename: Sunil R
authors.initials: SR
authors.lastname: Lakhani
authors.forename: Owen A
authors.initials: OA
authors.lastname: Ung
mesh_terms: D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007430:Intraoperative Care; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging / Q000473:pathology; D061305:Lymphoscintigraphy; D009367:Neoplasm Staging; D021141:Nucleic Acid Amplification Techniques; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy
keywords: axilla; breast cancer; cytology; hospital economics; sentinel lymph node biopsy