The importance of immunohistochemical expression of EGFr in squamous cell carcinoma of the oral cavity treated with surgery and postoperative radiotherapy

Smid, Ernst J.; Stoter, T. Rianne; Bloemena, Elisabeth; Lafleur, M. Vincent M.; Leemans, C. René; van der Waal, Isaac; Slotman, Ben J.; Langendijk, Johannes A.

doi:10.1016/j.ijrobp.2006.03.011

« Previous Next »International Journal of Radiation Oncology * Biology * Physics
Volume 65, Issue 5 , Pages 1323-1329, 1 August 2006

The importance of immunohistochemical expression of EGFr in squamous cell carcinoma of the oral cavity treated with surgery and postoperative radiotherapy

Ernst J. Smid, M.D.
- Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands
T. Rianne Stoter, B.Sc.
- Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands
Elisabeth Bloemena, M.D., Ph.D.
- Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands
- Department of Oral and Maxillofacial Surgery, VU University Medical Center, Amsterdam, The Netherlands
M. Vincent M. Lafleur, Ph.D.
- Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands
C. René Leemans, M.D., Ph.D.
- Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, Amsterdam, The Netherlands
Isaac van der Waal, S.D.D., Ph.D.
- Department of Oral and Maxillofacial Surgery, VU University Medical Center, Amsterdam, The Netherlands
Ben J. Slotman, M.D., Ph.D.
- Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands
Johannes A. Langendijk, M.D., Ph.D.
- Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands
- Department of Radiation Oncology, University Medical Center Groningen, Groningen, The Netherlands
- Reprint requests to: J. A. Langendijk, M.D., Ph.D., Department of Radiation Oncology, University Medical Center Groningen, PO Box 30001, 9300 RB Groningen, The Netherlands. Tel: (+31) 50-3611190; Fax: (+31) 50-3611692

Received 13 January 2006; received in revised form 17 February 2006; accepted 4 March 2006. published online 01 June 2006.

Purpose: 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 and Materials: 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.

Keywords: Head-and-neck cancer , Postoperative radiotherapy , EGFr expression , Overall treatment time