Cyclooxygenase 2 expression in nasopharyngeal carcinoma: immunohistochemical findings and potential implications.

Abstract

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.

• Authors: K-B Tan, T C Putti
• Journal: Journal of clinical pathology (J Clin Pathol) Vol. 58 Issue 5 Pg. 535-8 (May 2005) ISSN: 0021-9746 [Print] England
• PMID: 15858127 (Publication Type: Journal Article)

Chemical References

• Membrane Proteins
• Keratins
• Peroxidases
• Cyclooxygenase 2
• PTGS2 protein, human
• Prostaglandin-Endoperoxide Synthases

Topics

• Adult
• Aged
• Aged, 80 and over
• Carcinoma in Situ (blood supply, chemistry)
• Carcinoma, Squamous Cell (blood supply, chemistry)
• Cyclooxygenase 2
• Epithelium (chemistry, pathology)
• Herpesvirus 4, Human (isolation & purification)
• Humans
• Immunohistochemistry (methods)
• Keratins (metabolism)
• Membrane Proteins
• Microcirculation
• Middle Aged
• Nasopharyngeal Neoplasms (blood supply, chemistry)
• Neoplasm Staging
• Peroxidases (metabolism)
• Prostaglandin-Endoperoxide Synthases (analysis)