title: The importance of immunohistochemical expression of EGFr in squamous cell carcinoma of the oral cavity treated with surgery and postoperative radiotherapy.
abstract: OBJECTIVE
  The aim of this study was to investigate the prognostic significance of epidermal growth factor (EGFr) expression in oral cavity squamous cell carcinoma (OCSCC) treated with curative surgery and postoperative radiotherapy.
  
  
  METHODS
  This retrospective study included 165 OCSCC patients. The expression of EGFr was assessed on paraffin-embedded tissue of the primary tumor by immunohistochemistry using a monoclonal antibody directed against EGFr. Intensity of the EGFr expression was scored by two authors blinded for the clinical outcome.
  
  
  RESULTS
  In the univariate analysis, locoregional control at 3 years (LRC) in the EGFr-negative cases was 69% compared with 77% in the EGFr-positive cases (p = 0.22). In the multivariate analysis for local control, a significant interaction was found between EGFr and overall treatment time of radiation (OTT). After stratification for EGFr expression, the OTT was of no importance in the EGFr-negative cases, whereas a significant difference in LRC was found in the EGFr-positive cases, in which the LRC after 3 years was 69% and 94% in case of an OTT of 0-42 days and >42 days, respectively (p = 0.009; hazard ratio = 3.42; 95% confidence interval, 1.28-8.96). No significant association was found between EGFr expression and overall survival.
  
  
  CONCLUSIONS
  In the present study, no association was found between EGFr expression and outcome regarding locoregional control and overall survival. However, the results of the present study suggest that patients with squamous cell carcinoma of the oral cavity with high EGFr expression benefit more from a reduction of the overall treatment time of postoperative radiation than those with low EGFr expression.
authors.affiliation: Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Smid
authors.forename: T Rianne
authors.initials: TR
authors.lastname: Stoter
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bloemena
authors.forename: M Vincent M
authors.initials: MV
authors.lastname: Lafleur
authors.forename: C René
authors.initials: CR
authors.lastname: Leemans
authors.forename: Isaac
authors.initials: I
authors.lastname: van der Waal
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Slotman
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Langendijk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000401:mortality / Q000532:radiotherapy / Q000601:surgery; D003131:Combined Modality Therapy; D066246:ErbB Receptors / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000532:radiotherapy / Q000601:surgery; D009363:Neoplasm Proteins / Q000032:analysis*; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D009363:Neoplasm Proteins; D066246:ErbB Receptors