title: Detailed evaluation of one step nucleic acid (OSNA) molecular assay for intra-operative diagnosis of sentinel lymph node metastasis and prediction of non-sentinel nodal involvement: experience from a London teaching hospital.
abstract: One step nucleic acid (OSNA) is a molecular diagnostic assay for intra-operative detection of sentinel node metastases. This study compared OSNA with standard histopathology in 283 nodes from 170 patients to evaluate sensitivity, specificity and concordance of the two methods. Additional analysis was done to investigate how cytokeratin 19 mRNA copy number affects prediction of non-sentinel node positivity. OSNA sensitivity was 93.2% and specificity 95.8%. Concordance between OSNA and histology was 95.6%. In the patients who had axillary clearance, the OSNA mRNA copy number on the sentinel node had 100% negative predictive value for histologically proven metastasis. mRNA copy numbers <1400 were not associated with histologically proven metastasis in subsequent nodes at axillary clearance. OSNA is a reliable method for the intra-operative evaluation of axillary lymph node metastasis even when half of the lymph node is used. Identification of mRNA copy number threshold predicting the positivity of non-sentinel axillary nodes seems to be feasible and would be clinically important.
authors.affiliation: Department of Surgery, University College London, Royal Free London NHS Foundation Trust, UK.
authors.forename: Shramana M
authors.initials: SM
authors.lastname: Banerjee
authors.affiliation: Department of Surgery, University College London, Royal Free London NHS Foundation Trust, UK.
authors.forename: Nikolaos V
authors.initials: NV
authors.lastname: Michalopoulos
authors.affiliation: Clinical Trials Group, UCL Division of Surgery and Interventional Science, Centre for Clinical Science and Technology, Clerkenwell Building, Archway Campus, UK.
authors.forename: Norman R
authors.initials: NR
authors.lastname: Williams
authors.affiliation: Department of Surgery, University College London, Royal Free London NHS Foundation Trust, UK.
authors.forename: Timothy
authors.initials: T
authors.lastname: Davidson
authors.affiliation: Department of Pathology, Royal Free London NHS Foundation Trust, UK.
authors.forename: Soha
authors.initials: S
authors.lastname: El Sheikh
authors.affiliation: Department of Pathology, Royal Free London NHS Foundation Trust, UK.
authors.forename: Nuala
authors.initials: N
authors.lastname: McDermott
authors.affiliation: Department of Pathology, Royal Free London NHS Foundation Trust, UK.
authors.forename: My-Anh
authors.initials: MA
authors.lastname: Tran-Dang
authors.affiliation: Department of Pathology, Royal Free London NHS Foundation Trust, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Davison
authors.affiliation: Department of Surgery, University College London, Royal Free London NHS Foundation Trust, UK. Electronic address: m.keshtgar@ucl.ac.uk.
authors.forename: Mohammed R
authors.initials: MR
authors.lastname: Keshtgar
mesh_terms: D000368:Aged; D001365:Axilla; D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D018275:Carcinoma, Lobular / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D053539:Keratin-19 / Q000235:genetics*; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008408:Mastectomy; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques; D021141:Nucleic Acid Amplification Techniques; D061646:Operative Time; D012333:RNA, Messenger / Q000032:analysis*; D021701:Sentinel Lymph Node Biopsy
chemical_list: D014408:Biomarkers, Tumor; D053539:Keratin-19; D012333:RNA, Messenger
keywords: Breast cancer; Cytokeratin 19 mRNA copy number; OSNA; One step nucleic acid; Sentinel lymph node biopsy