title: A differential intra-operative molecular biological test for the detection of sentinel lymph node metastases in breast carcinoma. An extended experience from the first U.K. centre routinely offering the service in clinical practice.
abstract: BACKGROUND
  One-Step Nucleic acid Amplification (OSNA) is a molecular biological assay of cytokeratin-19 (a breast epithelial marker) mRNA. It can be employed intra-operatively for detection of lymph node metastases in breast carcinoma. Patients with positive sentinel nodes may proceed to axillary lymph node dissection (ALND) level I or higher dependent upon the OSNA quantitative result, during the same surgical procedure, avoiding a second operation and eliminating the technical difficulties possibly associated with delayed ALND.
  
  
  OBJECTIVE
  Our Breast Unit was the first in the UK to implement this novel technique in routine practice. This study reviews our first 44-month data following introduction of OSNA "live" on whole sentinel nodes following an extensive validation study (Snook et al.).(9) METHODS: Data was collected prospectively from the period of introduction 01/12/2008 to 30/08/2012. All patients eligible for sentinel node biopsy were offered OSNA and operations were performed by five consultant breast surgeons. On detection of macro-metastasis a level II/III and for a micro-metastasis a level I ALND was performed.
  
  
  RESULTS
  A total of 859 patients (1709 sentinel lymph nodes) were analysed. All except one were females. The majority underwent wide local excision (73.4%, n = 631) or mastectomy 25% (n = 215) and 1.6% (13) underwent SLN biopsy alone. IDC was seen in 79% (n = 680) of the patients and 53.5% (n = 460) had grade II tumours. One-third (30.8%, n = 265) had positive sentinel nodes and had further axillary surgery at the time of SLN biopsy. Of these, 47% (n = 125/265) had macro-metastases, 38% (n = 101/265) had micro-metastases and 14.7% (n = 39/265) had "positive but inhibited" results. Positive non-sentinel lymph nodes (NSLN) were seen in 35% (44/125) of those with macro-metastases; 17.8% (18/101) of the patients with micro-metastases and 10.2% (4/39) of the "positive but inhibited" group.
  
  
  CONCLUSIONS
  In our series over a third of our patients had positive lymph nodes detected with OSNA allowing them to proceed directly to axillary surgery at the same operation. This technique eliminates the need for a second operation in sentinel lymph node positive patients and avoids the anxiety waiting for histological results.
authors: Department of Breast and Oncoplastic Surgery, Royal Surrey County Hospital, Guildford, UK. Electronic address: mbabar@tcd.ie.
authors: M
authors: M
authors: Babar
authors: Department of Breast and Oncoplastic Surgery, Royal Surrey County Hospital, Guildford, UK.
authors: R
authors: R
authors: Madani
authors: Department of Histopathology, Royal Surrey County Hospital, Guildford, UK.
authors: L
authors: L
authors: Thwaites
authors: Department of Histopathology, Royal Surrey County Hospital, Guildford, UK.
authors: P A
authors: PA
authors: Jackson
authors: Department of Breast and Oncoplastic Surgery, Royal Surrey County Hospital, Guildford, UK.
authors: H L
authors: HL
authors: Devalia
authors: Department of Breast and Oncoplastic Surgery, Royal Surrey County Hospital, Guildford, UK.
authors: A
authors: A
authors: Chakravorty
authors: Department of Breast and Oncoplastic Surgery, Royal Surrey County Hospital, Guildford, UK.
authors: T E
authors: TE
authors: Irvine
authors: Department of Breast and Oncoplastic Surgery, Royal Surrey County Hospital, Guildford, UK; FHMS, University of Surrey, Guildford, UK.
authors: G T
authors: GT
authors: Layer
authors: Department of Breast and Oncoplastic Surgery, Royal Surrey County Hospital, Guildford, UK.
authors: M W
authors: MW
authors: Kissin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000401:mortality / Q000556:secondary* / Q000601:surgery; D016009:Chi-Square Distribution; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009361:Neoplasm Invasiveness / Q000473:pathology; D061206:Neoplasm Micrometastasis / Q000473:pathology; D009367:Neoplasm Staging; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D016522:Oncology Service, Hospital; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D015996:Survival Rate; D006113:United Kingdom
chemical_list: D012333:RNA, Messenger
keywords: Axillary node clearance (ANC); Cytokeratin-19 (CK-19); Micro-metastases in sentinel lymph node in breast cancer; Non-sentinel lymph node metastases; One-Step Nucleic acid Amplification (OSNA); Sentinel lymph node in breast cancer