A Comparative Study of Cyclooxygenase-2 Expression in Korean and Caucasian Patients with Early-Onset Breast Cancer / 한국유방암학회지

ABSTRACT

PURPOSE: Several studies have indicated that there are a number of differences in tumor biolog associated with race or ethnicity. The median age at the time of diagnosis for Korean women with breast cancer is 45 years, and this is approximately 15 years younger than Caucasian patients in the Western countries. We previously reported that was a significant difference found in the expression of HER-2/neu between Korean and Caucasian patients with early-onset breast carcinoma. In this study, we compared cyclooxygenase-2 (COX-2) expression between the two races. METHODS: One hundred and seventy two Korean women who were diagnosed with breast carcinoma at the age of 45 years or younger and 80 Caucasian women with breast carcinoma were selected for this study. The median age of both groups was 37 years and the tumor size was evenly distributed between the two group. Paraffin embedded blocks of primary tumor were processed for immunohistochemical COX-2 staining. The COX-2 expression was evaluated according to the percentage of positive cells and the intensity of staining. RESULTS: The proportion of tumors that stained positive for COX-2 in Korean and Caucasian women with early-onset breast carcinoma were 33.7% and 25%, respectively. The difference was not statistically significant (p = 0.104). Expression of COX-2 was associated with several clinicopathologic parameters, including positive lymph node status, large tumor size and negative estrogen receptor status. CONCLUSION: A significant difference was not found for the expression of COX-2 between the two groups of patients with early-onset breast carcinoma. Further research will be needed to identify the prognostic role for patients with early-onset breast carcinoma.