title: The diagnostic accuracy of reverse transcription-PCR quantification of cytokeratin mRNA in the detection of sentinel lymph node invasion in oral and oropharyngeal squamous cell carcinoma: a comparison with immunohistochemistry.
abstract: OBJECTIVE
  The main goal of sentinel lymph node (SLN) detection in head and neck squamous cell carcinomas is to limit neck dissections to pN+ cases only. However, intraoperative + diagnosis cannot be routinely done using the current gold standard, serial step sectioning with immunohistochemistry. Real-time quantitative reverse transcription-PCR (RT-PCR) is potentially compatible with intraoperative use, proving highly sensitive in detecting molecular markers. This study postoperatively assessed the accuracy of quantitative RT-PCR in staging patients from their SLN.
  
  
  METHODS
  A combined analysis on the same SLN by serial step sectioning with immunohistochemistry and quantitative RT-PCR targeting cytokeratins 5, 14, and 17 was done in 18 consecutive patients with oral or oropharyngeal squamous cell carcinoma and 10 control subjects.
  
  
  RESULTS
  From 71 lymph nodes examined, mRNA levels (KRT) were linked to metastasis size for the three cytokeratins studied (Pearson correlation coefficient, r = 0.89, 0.73, and 0.77 for KRT 5, 14, and 17 respectively; P < 0.05). Histopathology-positive SLNs (macro- and micrometastases) showed higher mRNA values than negative SLNs for KRT 17 (P < 10(-4)) and KRT 14 (P < 10(-2)). KRT 5 showed nonsignificant results. KRT 17 seemed to be the most accurate marker for the diagnosis of micrometastases of a size >450 mum. Smaller micrometastases and isolated tumor cells did not provide results above the background level. Receiver operating characteristic curve analysis for KRT 17 identified a cutoff value where patient staging reached 100% specificity and sensitivity for macro- and micrometastases.
  
  
  CONCLUSIONS
  Quantitative RT-PCR for SLN staging in cN(0) patients with oral and oropharyngeal squamous cell carcinoma seems to be a promising approach.
authors.affiliation: Departments of Head and Neck Surgery, Montpellier Teaching Hospital, Montpellier, France. r-garrel@chu-montpellier.fr
authors.forename: Renaud
authors.initials: R
authors.lastname: Garrel
authors.forename: Mathilde
authors.initials: M
authors.lastname: Dromard
authors.forename: Valérie
authors.initials: V
authors.lastname: Costes
authors.forename: Eric
authors.initials: E
authors.lastname: Barbotte
authors.forename: Frédéric
authors.initials: F
authors.lastname: Comte
authors.forename: Quentin
authors.initials: Q
authors.lastname: Gardiner
authors.forename: César
authors.initials: C
authors.lastname: Cartier
authors.forename: Marc
authors.initials: M
authors.lastname: Makeieff
authors.forename: Louis
authors.initials: L
authors.lastname: Crampette
authors.forename: Bernard
authors.initials: B
authors.lastname: Guerrier
authors.forename: Nathalie
authors.initials: N
authors.lastname: Boulle
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D053547:Keratin-14; D053555:Keratin-5; D007633:Keratins / Q000032:analysis / Q000235:genetics*; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis* / Q000235:genetics; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009367:Neoplasm Staging; D009959:Oropharyngeal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy
chemical_list: C507540:KRT14 protein, human; C503940:KRT5 protein, human; D053547:Keratin-14; D053555:Keratin-5; D012333:RNA, Messenger; D007633:Keratins