Study of molecular prognostic factors Bcl-2 and EGFR in rectal mucinous carcinomas

Colorectal cancer is an important public health problem worldwide, being the fourth most common cancer in men and the third most common in women. Colorectal cancer incidence is higher in developing countries due to the prevalence of obesity associated with reduced physical activity. Rectal mucinous carcinomas, especially the "signet ring cell" type, have a worse prognosis compared with other varieties of colorectal carcinomas, being diagnosed in more advanced stage and more prone to lymph node and peritoneal metastases. Our study comprised 37 cases with rectal adenocarcinoma with mucinous component operated in the Surgical Clinics of the Emergency County Hospital of Craiova, between 2006 and 2010. The aim of this study was to evaluate some molecular prognostic factors for rectal mucinous carcinomas namely B-cell lymphoma 2 (Bcl-2) and epidermal growth factor receptor (EGFR), and their correlations with the main morpho-clinical parameters of these patients. Thus, we immunohistochemically assessed the degree of apoptosis of tumor cells in mucinous rectal carcinomas using the Bcl-2 marker, and tumor aggressiveness using the EGFR responsiveness. In our study, the percentage of Bcl-2+ cases was 43.24%, with no significant statistical correlation between the Bcl-2 expression and histopathological subtype of mucinous adenocarcinoma. The evaluation of tumor aggressiveness in terms of EGFR responsiveness showed a reduced expression in carcinomas correlated with the increase in quantity of the mucinous component. In addition, EGFR reactivity was increased in the tumor invasion front.