Immunohistochemical Expression of Cyclooxygenase 2 (COX-2) as a Prognostic Marker and Its Correlation With Clinicopathological Parameters in Breast Cancer.

Introduction Breast cancer is considered the most common cancer among women. According to the literature, cyclooxygenase-2 (COX-2) expression in breast carcinoma is associated with aggressive tumor biology and acts as an independent prognostic marker. As COX-2 is a newly identified marker, studies are required to understand its immunoexpression and correlation with hormone receptor status and other prognostic factors, which helps in the therapeutic management of patients. Hence, this study evaluates the expression of COX-2 in breast carcinoma. Methods A hospital-based cross-sectional study was done on 55 mastectomy specimens collected at the Histopathology and Surgical Pathology Section of the Department of Pathology. The patient's age, histological type, tumor size, lymph node status, histological grade, and vascular invasion were noted. Immunohistochemical staining for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2/neu protooncogene (HER2/neu), and COX-2 markers was performed, and its results were compared with these clinicopathological and prognostic parameters. Results were subjected to statistical analysis. Results COX-2 expression was seen in 37 out of 55 cases (67.2%). Expression of COX-2 showed a statistically significant correlation with vascular invasion, ER-negative status, and PR-negative status. No statistical association was found between other parameters like age, tumor size, histological type, histological grade, lymph node status, and HER2/neu status. Conclusion The expression of COX-2 correlated strongly with well-established poor prognostic markers, such as vascular invasion, ER-negative status, and PR-negative status. Thus, expression of COX-2 suggests aggressive tumor biology, and it can be used as an independent prognostic marker.