Histopathological Evaluation and Analysis of Immunohistochemical Expression of Bcl-2 Oncoprotein in Colorectal...

Colorectal cancer is the third most prevalent malignancy with high mortality rate, necessitating markers that predict survival and guide the treatment. Previous studies have examined the immunohistochemical expression of Bcl-2, an apoptotic marker, in colorectal carcinoma, but results have been contradictory. To evaluate the histopathological features of colorectal carcinoma, immunohistochemical expression of Bcl-2 must be analyzed to find out statistical association of Bcl-2 expression with certain prognostic factors histopathologic type, grade and TNM staging.

This prospective study was conducted on the colectomy specimens of colorectal carcinoma, over a period of two years. The tumor morphology and Bcl-2 status were evaluated by immunohistochemistry in each case.

The study included 58 cases, with mean patient age of 47.07 years and male: female ratio of 1.89:1. Bcl-2 positivity was seen in 32.7% of the cases. Weak, moderate, and strong expression of Bcl-2 was seen in 12.1%, 12.1%, and 8.5% of cases respectively. Even though early stages of colorectal carcinoma showed greater frequency of Bcl-2 expression than advanced stages (36.3% versus 28%), however this association was not statistically significant.

Lack of statistically significant correlation between Bcl-2 immuno-histochemical expression and prognostic parameters like tumor grade and stage, suggests that Bcl-2 immunoexpression may not be a significant prognostic marker in colorectal carcinoma.