title: PTEN as a prognostic and predictive marker in postoperative radiotherapy for squamous cell cancer of the head and neck.
abstract: BACKGROUND
  Tumor suppressor PTEN is known to control a variety of processes related to cell survival, proliferation, and growth. PTEN expression is considered as a prognostic factor in some human neoplasms like breast, prostate, and thyroid cancer.
  
  
  RESULTS
  In this study we analyzed the influence of PTEN expression on the outcome of a randomized clinical trial of conventional versus 7-days-a-week postoperative radiotherapy for squamous cell cancer of the head and neck. The patients with cancer of the oral cavity, oropharynx, and larynx were randomized to receive 63 Gy in fractions of 1.8 Gy given 5 days a week (CF) or 7 days a week (p-CAIR). Out of 279 patients enrolled in the study, 147 paraffin blocks were available for an immunohistochemical assessment of PTEN. To evaluate the prognostic value of PTEN expression and the effect of fractionation relative to PTEN, the data on the outcome of a randomized clinical trial were analyzed. Tumors with a high intensity of PTEN staining had significant gain in the loco-regional control (LRC) from p-CAIR (5-year LRC 92.7% vs. 70.8%, for p-CAIR vs. CF, p = 0.016, RR = 0.26). By contrast, tumors with low intensity of PTEN did not gain from p-CAIR (5-year LRC 56.2% vs. 47.2%, p = 0.49, RR = 0.94). The intensity of PTEN highly affected the LRC in a whole group of 147 patients (5-year LRC 80.9% vs. 52.3% for high vs. low PTEN, p = 0.0007, RR = 0.32). In multivariate Cox analysis, including neck node involvement, EGFR, nm23, Ki-67, p53, cyclin D1, tumor site and margins, PTEN remained an independent predictor of LRC (RR = 2.8 p = 0.004).
  
  
  CONCLUSIONS
  These results suggest that PTEN may serve as a potent prognostic and predictive marker in postoperative radiotherapy for high-risk squamous cell cancer of the head and neck.
authors.affiliation: Tumor Pathology Department, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Poland. mirek@snietura.net
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Snietura
authors.forename: Magdalena
authors.initials: M
authors.lastname: Jaworska
authors.forename: Joanna
authors.initials: J
authors.lastname: Mlynarczyk-Liszka
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Goraj-Zajac
authors.forename: Wojciech
authors.initials: W
authors.lastname: Piglowski
authors.forename: Dariusz
authors.initials: D
authors.lastname: Lange
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Wozniak
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Nowara
authors.forename: Rafal
authors.initials: R
authors.lastname: Suwinski
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000401:mortality / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D011184:Postoperative Period; D011379:Prognosis; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D051059:PTEN Phosphohydrolase