title: Toll-like receptor 5 (TLR5) expression is a novel predictive marker for recurrence and survival in squamous cell carcinoma of the tongue.
abstract: BACKGROUND
  Toll-like receptor 5 (TLR5) is an immune receptor recognising bacterial flagellin. Activation of TLR5 results in cancer invasion and cytokine release. As certain bacteria have been linked to oral cancer, we wanted to study TLR5 expression in oral tongue squamous cell carcinoma (OTSCC).
  
  
  METHODS
  Samples from 119 patients with OTSCC were obtained, including 101 samples of adjacent normal lingual mucosa. The TLR5 histoscore (0-300) was assessed semiquantitatively by immunohistochemistry in a blinded manner.
  
  
  RESULTS
  Toll-like receptor 5 was expressed in 84 normal epithelia and 118 cancer samples. Expression of TLR5 was increased in cancer when compared with normal lingual epithelium (median histoscore 15 vs 135). In cancer, higher TLR5 was associated with age of >70 years at the time of diagnosis, female gender and disease recurrence. No association between TLR5 expression and tumour grade, stage or treatment was found. In multivariate analysis, TLR5 was an independent predictor of cancer mortality (hazard ratio (HR) 3.587, 95% confidence interval (CI) (1.632-7.882)) and disease recurrence (HR 4.455, 95% CI (2.168-9.158)).
  
  
  CONCLUSIONS
  Toll-like receptor 5 has a previously undescribed role in the pathophysiology of OTSCC and might represent a link between bacteria and cancer. It could be a useful marker for predicting recurrence or survival of OTSCC patients.
authors.affiliation: Department of Pathology, University of Oulu, PO Box 5000, 90014 Oulu, Finland. joonas.kauppila@oulu.fi
authors.forename: J H
authors.initials: JH
authors.lastname: Kauppila
authors.forename: A E
authors.initials: AE
authors.lastname: Mattila
authors.forename: T J
authors.initials: TJ
authors.lastname: Karttunen
authors.forename: T
authors.initials: T
authors.lastname: Salo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000401:mortality* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000378:metabolism / Q000401:mortality* / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate; D051198:Toll-Like Receptor 5 / Q000378:metabolism*; D014059:Tongue / Q000378:metabolism*; D014062:Tongue Neoplasms / Q000378:metabolism / Q000401:mortality* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; C495346:TLR5 protein, human; D051198:Toll-Like Receptor 5