PT  - JOURNAL ARTICLE
AU  - Tan, K-B
AU  - Putti, T C
TI  - Cyclooxygenase 2 expression in nasopharyngeal carcinoma: immunohistochemical findings and potential implications
AID  - 10.1136/jcp.2004.021923
DP  - 2005 May 01
TA  - Journal of Clinical Pathology
PG  - 535--538
VI  - 58
IP  - 5
4099  - http://jcp.bmj.com/content/58/5/535.short
4100  - http://jcp.bmj.com/content/58/5/535.full
SO  - J Clin Pathol2005 May 01; 58
AB  - Background: Cyclooxygenase 2 (COX-2), an inducible prostaglandin synthase, participates in inflammatory and neoplastic processes. It is expressed by various tumours and contributes to carcinogenesis. Notably, COX-2 inhibitors appear to have tumour suppressor effects and are being evaluated in clinical trials. Aims: To investigate COX-2 expression in nasopharyngeal carcinoma (NPC), a common tumour in parts of Asia, and to discuss potential implications. Methods: Eighty five cases of NPC were reviewed. COX-2 immunohistochemistry and semiquantitative assessment of expression in nasopharyngeal biopsies were performed. Because COX-2 is proangiogenic, tumour microvessel density was also assessed with the use of CD31 immunohistochemistry. Results: Histologically, 78 NPCs were undifferentiated, six were non-keratinising, and one was keratinising. Thirty nine NPCs had adjacent dysplastic epithelium. COX-2 expression was noted in 60 NPCs, 14 of 39 samples of dysplastic epithelium, and only one of 25 samples of normal epithelium (p < 0.01). Microvessel density was not significantly different between COX-2 positive and COX-2 negative tumours (p  =  0.774). Tumour COX-2 positivity was not associated with higher tumour stage (p  =  0.423). Conclusion: COX-2 expression is more frequently seen as nasopharyngeal epithelium progresses from normal to dysplastic to carcinoma. This suggests that COX-2 contributes to the multistep process of NPC carcinogenesis. COX-2 represents a therapeutic target for COX-2 inhibitors, and there is thus a basis for the further investigation of this adjuvant treatment modality for NPC. COX-2 inhibitors are known to potentiate the antitumour effects of radiotherapy, which is the primary treatment for NPC.