A study of Bcl-2 and p-53 immunostaining expressions in colonic carcinomas

Abstract

Background: Colorectal cancer burden has been steadily rising in women. It was the fourth most common cancer in 1975 and has reached the second position by 1990, with about 49% increase in the number of cases globally over a period of 15 yrs. From 1999–2008, the rate of people dying from colorectal cancer has varied, depending on their race and ethnicity. Objective: To study Bcl-2 and p-53 immunostaining expressions in colonic carcinomas. Methods: The present study is both a retrospective and a prospective study. The study is based on histomorphological evaluation of 30 resected specimen of Colorectal Carcinomas received at the department of Pathology, Osmania General Hospital in a 2 year period from June 2009 to May 2011. The most representative block for all 30 cases was then selected for immune histochemical analysis of p-53 protein and Bcl-2 Oncoprotein for p-53 immunostaining, we used the DO-7 monoclonal antibody (dilution 1:30; DAKO), and, for Bcl-2, the monoclonal antibody 124 was used (dilution 1:80; DAKO). Results: Positive staining for p-53 protein was detected in 56.67% ( 17/30 ) of colorectal adenocarcinomas. There is statistically no significant association observed between p53 expression and Dukes' stage, TNM stage or Histological grade (p value > 0.05). Similarly no association was found between expression of p-53 and other patient variables, such as age, sex, location of tumor, & tumor differentiation. In the present study statistically there is no significant association between Bcl-2 & p-53 either individually or combined together with any of the parameters (like age, sex, tumor location, Dukes' stage, Histological grade & TNM stage). Conclusion: Though not statistically significant, to comment as the optimism expressed by certain investigators due to the low number of cases taken up for the present study, a large study group is needed to comment on the prognostic significance of the Bcl-2 & p-53 immuno profile individually and in a combined variation to predict the clinical outcome.

Keywords

• bcl-2
• p-53
• immunostaining