title: Intraoperative Sentinel Lymph Node Evaluation: Implications of Cytokeratin 19 Expression for the Adoption of OSNA in Oral Squamous Cell Carcinoma.
abstract: Intraoperative analysis of sentinel lymph nodes would enhance the care of early-stage oral squamous cell carcinoma (OSCC). We determined the frequency and extent of cytokeratin 19 (CK19) expression in OSCC primary tumours and surrounding tissues to explore the feasibility of a "clinic-ready" intraoperative diagnostic test (one step nucleic acid amplification-OSNA, sysmex).
  
  
  
  Two cohorts were assembled: cohort 1, OSCC with stage and site that closely match cases suitable for sentinel lymph node biopsy (SLNB); cohort 2, HNSCC with sufficient fresh tumour tissue available for the OSNA assay (>50 mg). CK19 assays included qRT-PCR, RNA in situ hybridisation (ISH), and immunohistochemistry (IHC), as well as OSNA.
  
  
  
  CK19 mRNA expression was detected with variable sensitivity, depending on method, in 60-80% of primary OSCC tumours, while protein expression was observed in only 50% of tumours. Discordance between different techniques indicated that OSNA was more sensitive than qRT-PCR or RNA-ISH, which in turn were more sensitive than IHC. OSNA results showed CK19 expression in 80% of primary cases, so if used for diagnosis of lymph node metastasis would lead to a false-negative result in 20% of patients with cervical lymph node metastases.
  
  
  
  OSNA in its current form is not suitable for use in OSCC SLNB due to inadequate expression of the CK19 target in all case. However, the same assay technology would likely be very promising if applied using a more ubiquitous squamous epithelial target.
authors.affiliation: Department of Molecular Clinical Cancer Medicine, Mersey Head & Neck Oncology Group, University of Liverpool, Liverpool, UK. rjshaw@liv.ac.uk.
authors.forename: Richard
authors.initials: R
authors.lastname: Shaw
authors.affiliation: Department of Otolaryngology, Head & Neck Surgery and Audiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Christensen
authors.affiliation: Department of Molecular Clinical Cancer Medicine, Mersey Head & Neck Oncology Group, University of Liverpool, Liverpool, UK.
authors.forename: Kapil
authors.initials: K
authors.lastname: Java
authors.affiliation: Department of Molecular Clinical Cancer Medicine, Mersey Head & Neck Oncology Group, University of Liverpool, Liverpool, UK.
authors.forename: Rehab El
authors.initials: RE
authors.lastname: Maddani
authors.affiliation: Department of Molecular Clinical Cancer Medicine, Mersey Head & Neck Oncology Group, University of Liverpool, Liverpool, UK.
authors.forename: Triantafillos
authors.initials: T
authors.lastname: Liloglou
authors.affiliation: Cellular Pathology, Aintree University Hospitals NHS Foundation Trust, Liverpool, UK.
authors.forename: Triantafyllou
authors.initials: T
authors.lastname: Asterios
authors.affiliation: Department of Otolaryngology, Head & Neck Surgery and Audiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: von Buchwald
authors.affiliation: Department of Otolaryngology, Head & Neck Surgery and Audiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Irene
authors.initials: I
authors.lastname: Wessel
authors.affiliation: Department of Pathology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Katalin
authors.initials: K
authors.lastname: Kiss
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kjaer
authors.affiliation: Department of Pathology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Giedrius
authors.initials: G
authors.lastname: Lelkaitis
authors.affiliation: Cellular Pathology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: Long
authors.affiliation: Department of Molecular Clinical Cancer Medicine, Mersey Head & Neck Oncology Group, University of Liverpool, Liverpool, UK.
authors.forename: Janet
authors.initials: J
authors.lastname: Risk
authors.affiliation: Centre for Oral Health Research, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Max
authors.initials: M
authors.lastname: Robinson
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D005188:False Negative Reactions; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007432:Intraoperative Period; D053539:Keratin-19 / Q000235:genetics* / Q000378:metabolism; D008207:Lymphatic Metastasis; D009062:Mouth Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009367:Neoplasm Staging; D021141:Nucleic Acid Amplification Techniques; D012333:RNA, Messenger / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D000071036:Sentinel Lymph Node / Q000378:metabolism* / Q000473:pathology; D021701:Sentinel Lymph Node Biopsy
chemical_list: D053539:Keratin-19; D012333:RNA, Messenger