Detection of cyclooxygenase-2 [COX-2] expression in non-small cell lung carcinoma. An immunohistochemical and computerized image analysis study

ABSTRACT

Lung cancer is the leading cause of cancer death all over the world. Evidence is accumulating to suggest that cyclooxygenase-2 [COX-2] is involved the pathogenesis and progression of some types of lung cancer. COX-2 is one of the novel targets under evaluation for non-small cell lung carcinoma [NSCLC] therapy and chemoprevention. The aim of the present study was to detect COX-2 expression in non-small cell lung carcinoma [NSCLC] and to determine its correlation with various clinic pathological parameters. The expression of COX-2 was assessed in 30 patients with NSCLC using immunohistochemistry, followed by quantitative assessment of the immunostaining using computerized image analysis. The present work was conducted on 30 patients with NSCLC squamous cell carcinoma [15 patients], adenocarcinoma [10 patients], and undifferentiated large cell carcinoma [5 patients]. Overall, 70% of studied NSCLC expressed COX-2. 60% of squamous cell carcinoma [SCC], 80% of adenocarcinoma [ADC] and 80% of undifferentiated large cell carcinoma [ULCC] showed positive immunostaining for COX-2. No significant correlation was found between tumor histological type and each of frequency and degree of COX-2 expression [p=0.569 and p=0.094 respectively]. Though the expression of COX-2 increased with tumor grade, the relation between COX2 expression [both the frequency and degree of expression] and tumor grade was not significant [p=0.778 and p=0.247 respectively for SCC, and p=0.641 and p=0.067 respectively for ADC]. A statistically significant difference was found between node positive and node negative cases as regards the degree of COX2 expression [p=0.05]. No significant relationship was found between COX-2 expression and age and sex of patients, smoking and tumor stage. COX-2 is frequently overexpressed in NSCLC especially in adenocarcinoma and undifferentiated large cell carcinoma. Expression was higher in node-positive tumors and tended to increase with tumor grade, suggesting that COX-2 might play a role in the pathogenesis and/or progression of these tumors. COX-2 appears to be a potentially promising target for therapy and chemoprevention of NSCLC