title: Loss of PTEN expression as a prognostic marker for tongue cancer.
abstract: BACKGROUND
  Abnormalities of PTEN, a candidate tumor suppressor gene located at 10q23.3, play an important role in the tumorigenesis of multiple tumor types.
  
  
  OBJECTIVE
  To investigate the expression of PTEN and its clinical implication in squamous cell carcinoma of the tongue.
  
  
  METHODS
  Retrospective analysis of PTEN protein expression in archived primary oral tongue tumor samples.
  
  
  METHODS
  Academic center.
  
  
  METHODS
  PTEN expression was determined by immunohistochemical analysis in tissue samples from 41 patients with stage II, III, and IV squamous cell carcinoma of the tongue. All the patients underwent curative surgical treatment with a median follow-up of 81 months. The Kaplan-Meier method was used for survival analysis. Multivariate analysis was performed according to the Cox proportional hazards model.
  
  
  RESULTS
  Lack of staining for PTEN was demonstrated in 12 (29%) of the 41 tumors. Patients whose tumors lacked PTEN expression had a significantly shorter overall survival time (P = .03) and event-free survival time (P = .01) than those patients with positive PTEN expression. Multivariate regression analysis demonstrated that PTEN expression is an independent predictor of poor outcome when compared with tumor stage and nodal status.
  
  
  CONCLUSIONS
  Although genetic alterations of the PTEN gene are rare in head and neck squamous cell carcinoma, loss of PTEN is not an uncommon event in squamous cell carcinoma of the tongue. Lack of PTEN expression may be an independent prognostic indicator for clinical outcome in patients with this tumor type.
authors.affiliation: Bobby R. Alford Department of Otorhinolaryngology and Communicative Sciences, Baylor College of Medicine, Houston, TX, USA.
authors.forename: J I
authors.initials: JI
authors.lastname: Lee
authors.forename: J C
authors.initials: JC
authors.lastname: Soria
authors.forename: K A
authors.initials: KA
authors.lastname: Hassan
authors.forename: A K
authors.initials: AK
authors.lastname: El-Naggar
authors.forename: X
authors.initials: X
authors.lastname: Tang
authors.forename: D D
authors.initials: DD
authors.lastname: Liu
authors.forename: W K
authors.initials: WK
authors.lastname: Hong
authors.forename: L
authors.initials: L
authors.lastname: Mao
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality; D005260:Female; D016147:Genes, Tumor Suppressor; D005819:Genetic Markers; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D051059:PTEN Phosphohydrolase; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics*; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D014062:Tongue Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D005819:Genetic Markers; D025521:Tumor Suppressor Proteins; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human