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. 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 treated at 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 was 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 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 sign ificant (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. 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.