title: The real-time intra-operative evaluation of sentinel lymph nodes in breast cancer patients using One Step Nucleic Acid Amplification (OSNA) and implications for clinical decision-making.
abstract: BACKGROUND
  One Step Nucleic Acid Amplification (OSNA) method for the intraoperative analysis of sentinel lymph nodes (SLNs) in breast cancer, obviates a second operation to the axilla and thereby expedites progression to adjuvant therapy. Recent NICE guidelines have approved OSNA as a method of sentinel node diagnosis to support the above case.(1) METHOD: This is a single centre prospective cohort analysis of all patients undergoing breast cancer surgery including sentinel node biopsy from February 2010 to June 2012. Patients with negative SLN(s) on OSNA had no further axillary surgery. A validation phase was performed prior to using OSNA routinely. Those with micrometastases underwent a level 1 clearance, and >one SLN with macrometastases, underwent treatment by level 2 axillary dissection. The length of time from sentinel node retrieval to OSNA result was recorded.
  
  
  RESULTS
  Four hundred and forty nodes were analysed in 212 patients with a mean age of 55 years (range 24-98). The sensitivity and specificity of OSNA was 93% and 94% respectively in cases of macrometastases. The process required additional median anaesthesia time of 20 min (range -48 to +65 min). Non-sentinel node positivity was 5% and 48% for micrometastasis and macrometastasis respectively.
  
  
  CONCLUSIONS
  OSNA identified 62 of 212 patients with at least one positive sentinel node, thereby sparing 29% from a second procedure to clear the axilla subsequently. The median waiting time of 20 min for node results from completion of breast procedure is acceptable and allows for an efficient operating list. OSNA can be incorporated into routine practice and with improved methods of imaging preoperatively, can be an excellent adjunct to the breast cancer patient pathway of care.
authors.affiliation: Department of Breast Surgery, University Hospitals Bristol NHS Trust, United Kingdom. Electronic address: mastersurg@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Chaudhry
authors.affiliation: Department of Breast Surgery, University Hospitals Bristol NHS Trust, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Williams
authors.affiliation: Department of Breast Surgery, University Hospitals Bristol NHS Trust, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Cook
authors.affiliation: Department of Histopathology, University Hospitals Bristol NHS Trust, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Jenkins
authors.affiliation: Department of Histopathology, University Hospitals Bristol NHS Trust, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Sohail
authors.affiliation: Department of Histopathology, University Hospitals Bristol NHS Trust, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Calder
authors.affiliation: Department of Breast Surgery, University Hospitals Bristol NHS Trust, United Kingdom; School of Clinical Sciences, University of Bristol, Level 7, Research and Teaching, United Kingdom.
authors.forename: Z E
authors.initials: ZE
authors.lastname: Winters
authors.affiliation: Department of Breast Surgery, University Hospitals Bristol NHS Trust, United Kingdom.
authors.forename: Z
authors.initials: Z
authors.lastname: Rayter
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001943:Breast Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D018275:Carcinoma, Lobular / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D053539:Keratin-19 / Q000235:genetics; D008197:Lymph Node Excision / Q000379:methods; D008198:Lymph Nodes / Q000378:metabolism*; D008875:Middle Aged; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D061646:Operative Time; D011446:Prospective Studies; D012333:RNA, Messenger / Q000032:analysis*; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D055815:Young Adult
chemical_list: D053539:Keratin-19; D012333:RNA, Messenger
keywords: Axillary dissection; Breast cancer; OSNA; Sentinel lymph node