Cyclooxygenase-2 Expression in Colorectal Cancer

ABSTRACT

PURPOSE: Cyclooxygenase (COX) is an important enzyme that transforms arachidonic acid into prostaglandins and exists as two types of isoenzyme, COX-1 and COX-2. Recently, the expression of COX-2 was presented as an important factor in determining the prognosis in colorectal cancer, and the expressed COX-2 was related with recurrence and liver metastasis after an operation for colorectal cancer. Thus this study was to investigate the relationship between COX-2 expression and the prognosis for colorectal cancer. METHODS: We studied colorectal cancer patients who received operations at the Catholic University of Korea from Jan. 1993 through Dec. 2000, by reviewing their medical records and pathological reports. We used immunohistochemistry to determine the expression rate of COX-2 and to study its relationship with other clinical variables, the disease-free survival rat, and the recurrence rate. RESULTS: Among the 217 cases, 171 cases (78.8%) showed positive COX-2 expression. The COX-2 expression increased with the differentiation and was lower in cases with lymph-node metastasis. However, no statistically significant difference in age, sex, location of lesion, invasiveness, stage, organ of metastasis, disease-free survival rate, and recurrence existed between patients with positive COX-2 expression and those with negative COX-2 expression. CONCLUSIONS: There is no evidence that COX-2 expression is associated with a poor prognosis for colorectal cancer.