Cyclooxygenase-2 expression as a predictor of outcome in colorectal carcinoma

AIM:To correlate cyclooxygenase-2(COX-2)expression profile with clinical and pathological variables to assess their prognostic/predictive value in colorectal carcinoma(CRC).METHODS:Archival tumor samples were analyzed using immunohistochemistry for COX-2 expression in 94 patients with CRC.Patients were diagnosed and treatedat the Departments of Surgery and Oncology,King Abdulaziz University Hospital,Saudi Arabia.RESULTS:Fifty-six percent of the tumors showed positive cytoplasmic COX-2 expression,whereas 44%of cases were completely COX-2-negative.There were no significant correlations between COX-2 expression and sex,age,grade or tumor location.However,COX-2 expression revealed a significant correlation with tumor stage(P=0.01)and distant metastasis(P=0.02),and a borderline association with lymph node involvement(P =0.07).Tumors with high COX-2 expression showed a higher recurrence rate than tumors with no expression(P<0.009).In univariate Kaplan-Meier survival analysis,there was a significant(P=0.026)difference in disease-free survival between COX-2-positive and negative tumors in favor of the latter.COX-2 expression did not significantly predict disease-specific survival,which was much shorter for COX-2-positive tumors.In multivariate(COX)models,COX-2 did not appear among the independent predictors of disease-free survival or disease-specific survival.CONCLUSION:COX-2 expression seems to provide useful prognostic information in CRC,while predicting the patients at high risk for recurrent disease.