title: Reliability of whole sentinel lymph node analysis by one-step nucleic acid amplification for intraoperative diagnosis of breast cancer metastases.
abstract: OBJECTIVE
  To assess the reliability of using the One-Step Nucleic Acid Amplification (OSNA) assay as a single test on whole sentinel lymph nodes (SLN) as a method of intraoperative diagnosis and staging of SLNs in breast cancer.
  
  
  BACKGROUND
  Combining histological and molecular assessment of metastasis on the same SLN may not fully reproduce the actual load of cancer cells present in the SLN and create problems in decisions regarding axillary dissection.
  
  
  METHODS
  Selection criteria for the whole SLN OSNA test required that the primary tumor expressed CK19 in more than 80% of tumor cells. Imprint cytology analysis of SLNs was performed together with the OSNA.
  
  
  RESULTS
  Of the 279 patients enrolled for SLN evaluation, 123 gave consent to the OSNA protocol and 156 to the standard histology. Thirteen patients were excluded from OSNA evaluation because of low CK19 gene expression in the primary tumor; only 2.3% were truly negative. The kappa of concordance between the imprint cytology and OSNA results was 0.52. The rate of macrometastases determined by OSNA was 11% versus 20% determined by histology, whereas the rate of OSNA-micrometastases (18%) was significantly higher than that determined by histology (8%). The rate of SLN-negative cases was similar between the 2 protocols. Macrometastases correlated with the presence of vascular invasion in both protocols. The rate of axillary lymph node metastases was consistent with SLN tumor load.
  
  
  CONCLUSIONS
  Intraoperative OSNA assay performed on the whole SLN gave objective and reproducible results that were useful for directing decisions regarding axillary dissection and for accurately defining the SLN stage.
authors.affiliation: Department of Biomedical Sciences and Human Oncology, University of Turin, Turin, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Castellano
authors.forename: Luigia
authors.initials: L
authors.lastname: Macrì
authors.forename: Cristina
authors.initials: C
authors.lastname: Deambrogio
authors.forename: Davide
authors.initials: D
authors.lastname: Balmativola
authors.forename: Riccardo
authors.initials: R
authors.lastname: Bussone
authors.forename: Ada
authors.initials: A
authors.lastname: Ala
authors.forename: Claudio
authors.initials: C
authors.lastname: Coluccia
authors.forename: Anna
authors.initials: A
authors.lastname: Sapino
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D053539:Keratin-19 / Q000235:genetics*; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008875:Middle Aged; D061206:Neoplasm Micrometastasis / Q000175:diagnosis; D009367:Neoplasm Staging / Q000379:methods*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D015203:Reproducibility of Results; D021701:Sentinel Lymph Node Biopsy
chemical_list: D014408:Biomarkers, Tumor; D053539:Keratin-19