Beta-catenin and p53 expression in topographic compartments of colorectal cancer and its prognostic value following surgery

Colorectal cancer (CRC) is the third most prevalent neoplasm worldwide and the fourth cause of cancer-related death. From Vogelstein's initial model, new molecular knowledge has been incorporated which includes an elevated number of genetic mutations, many of them located in the Wnt pathway, which affect its principle effector: beta-catenin. Additionally, it is necessary to keep the heterogeneity of CRCs in mind, both in terms of morphology and biology. The aim of this work is to study the interaction between the Wnt molecular pathway, by means of immunoexpression of beta-catenin, in CRC and other molecular mechanisms, such as the p53 pathway, in order to determine the pattern - if one exists - of different immunohistochemical expression of beta-catenin and p53 in the superficial and deep tumor components, and lastly, to determine the impact of these markers on prognosis. Our cases showed an increasing gradient of beta-catenin immunoexpression that parallels depth in the tumor, with a greater degree of nuclear immunoexpression in the deep compartment. We observe that in those cases with positivity for nuclear p53 and an absence of immunostaining of beta-catenin show higher rates of survival, whereas one of the lowest rates was observed in patients who co-expressed p53 and beta-catenin. We conclude that a combined analysis of beta-catenin and p53 could have prognostic importance as markers for predicting the disease's progression and contribute to the identification of patients with a high risk of mortality.