Abstract
Problem
Over expression of Cyclooxygenase II (COX II) is noted in a variety of inflammatory and neoplastic conditions, including laryngeal cancer. Although smoking is a known risk factor for laryngeal carcinoma, non-smokers are occasionally diagnosed. Possible etiologic factors include up regulation of COX II expression. This study compares COX II expression in benign, dysplastic and cancerous laryngeal tissue specimens in smokers and non-smokers.
Methods
Pathology specimens from consecutive patients who underwent excision of a laryngeal lesion for unrelated reasons from 2003 to 2006 were collected. Patients with severe laryngopharyngeal reflux were excluded. Patients’ smoking history was collected. Immunocytochemical studies were used to detect COX II expression. A blinded pathologist graded the intensity of COX II expression based on a visual analog scale. Statistical analysis was used to determine differences.
Results
49 samples from 22 smokers and 18 non-smokers were tested. COX II expression was significantly larger in cancerous lesions of smokers vs non-smokers and in dysplastic vs benign lesions in non-smokers. A non-statistically significant trend of consistent and progressive increase in COX II expression with increasing dysplasia in smokers was noted.
Conclusion
The increase in COX II expression between benign and dysplastic lesions in non-smokers may be due to a loss of regulation of cell metabolism. This effect may be HPV mediated and further studies comparing HPV positivity with COX II expression are underway. The significantly higher COX II expression in cancerous lesions of smokers vs non-smokers be due to the persistent and chronic mucosal irritation from smoking.
Significance
This translational research may affect treatment and prevention of laryngeal carcinoma in non-smokers. A correlation between increased COX II expression and pathologic diagnosis would support the role for the use of COX II inhibitors in the prevention of progression of laryngeal lesions.
Support
Research grant from the Department of Otolaryngology, University of Rochester, New York.
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