Expression of Cox-2 Immunohistochemistry in Colorectal Cancer and its Correlation with Clinicopathological Parameters

Background: Colorectal cancer (CRC) is one of the leading causes of cancer-related morbidity and mortality worldwide. Cyclooxygenase-2 (COX-2) plays an important role in colorectal carcinogenesis by promoting tumor cell proliferation, angiogenesis, invasion, and inhibition of apoptosis. Evaluation of COX-2 expression may provide valuable prognostic information and identify potential therapeutic targets in colorectal adenocarcinoma.

Aim: To evaluate the clinicopathological profile of colorectal adenocarcinoma, assess and correlate COX-2 expression by immunohistochemistry with clinicopathological parameters.

Materials and Methods: This was a 3-year cross-sectional ambispective study conducted by Department of Pathology in a tertiary care rural institution. A total of 50 histopathologically confirmed cases of colorectal adenocarcinoma diagnosed on biopsy or resection specimens were included. Clinical and histopathological details were recorded, and immunohistochemistry for COX-2 was performed using monoclonal antibody. COX-2 expression was evaluated based on staining intensity and the percentage of positively stained tumor cells. Statistical analysis was performed using SPSS version 25.0, and a p-value <0.05 was considered statistically significant.

Results: The mean age of the patients was 53.04 ± 16.05 years, with a slight female predominance (52%). Pain abdomen (44.0%) was the most common presenting complaint. Biopsy specimens constituted majority of the cases (68.0%), with right-sided colon being the most frequently involved site (36.0%). Moderately differentiated adenocarcinoma was the predominant histological grade (92.0%). Strong COX-2 staining intensity was observed in 66.0% of cases, of which 88.0% of tumors showed positivity in 76–100% of tumor cells. COX-2 total score showed a significant positive correlation with tumor (rₛ = 0.341, p = 0.041) and nodal stage (rₛ = 0.298, p = 0.048), whereas no significant association was found with age, sex, or histological grade.

Conclusion: COX-2 was highly expressed in the majority of colorectal adenocarcinoma cases and demonstrated significant association with advanced tumor stage and lymph node involvement. These findings suggest that COX-2 may serve as a useful prognostic biomarker and a potential therapeutic target in colorectal adenocarcinoma