Expression of Cyclooxygenase-1 and 2 in Epithelial Ovarian Cancer: A Clinicopathologic Study

BACKGROUND: To examine the rate and degree of expression of Cyclooxygenase-1 (COX-1) and Cyclooxygenase-2 (COX-2) in epithelial ovarian cancer (EOC) and associated with clinicopathological factors and survival. METHODS: EOC patients being treated in our institute with available pathological tissue sections during 1996-2003 were identified. Immunohistochemical staining with antibody to COX-1 and COX-2 were studied. Degree of expression was categorized into low and high levels. The degrees of immunohistochemistry staining were associated with clinicopathological factors and overall survival. RESULTS: A total of 107 patients were included in the study. Most of patients had stage 1 and 3, and the most common histology type was serous carcinoma. The expression rate of COX-1 and COX-2 was 83.2 % and 95.3 %, respectively. Non-mucinous tumor had significant higher level of expression of both COX-1 and COX-2. Except for a high level of expression of COX-2 in association with better response to chemotherapy, no significant association with other clinicopathologic factors were observed. Level of COX-1 or COX-2 expression did not associate with progression-free and overall survival. The combination of COX-1 and COX-2 level was analyzed and the combination of high COX-1 and low COX-2 level significant associated with short progression-free and overall survival. CONCLUSION: EOC in our study showed high rate of COX-1 and COX-2 expression, especially in non-mucinous tumors. High level of COX-2 associated with better response to chemotherapy. Neither COX-1 nor COX-2 expression showed association with survivals while combination of high COX-1 and low COX-2 level of expression was associated with poor progression-free and overall survivals.