Avaliação da Expressão das Proteinas Cerb-B2, P53 e Instabilidade de Microssatélites no Adenocarcinoma Colorretal no Estado do Tocantins

Abstract

Colorectal cancer (CRC) is one of the most common neoplasms in the world. In Brazil there is a delay in diagnosis and treatment of CRC, what cause a high mortality rates. Microsatellite instability (MSI) is an important prognostic factor, and it has a significant potential in the classification of patients for chemotherapy treatment. Other molecular markers in CCR are cerb-B2 and p53 proteins, that are currently widely used to guide the prognosis and individualized treatment. Thus, the aim of this study was to correlate the immunohistochemical expression of p53, cerb-B2 and MSI markers to clinical and pathological parameters, in people with CRC in the state of Tocantins. For this, a cross-sectional study was performed between March 2017 and March 2019. Colorectal samples were submitted to anatomopathological and immunohistochemical examination to detection of CCR. The immunohistochemical study was performed for the MSI, cerb-B2 and p53 markers. The histological classification used was the proposed by the World Health Organization. Fisher's test was performed to evaluate the differences between the proportions of p53, cerb-B2 and MSI markers with clinical and pathological parameters. Values of p ≤0.05 were considered statistically significant. The study included 77 patients with mean age of 60.1 ± 14.8 years. It stands out that age was a risk factor for CRC because tumor presence increased with age, and more than 50% of cases occurred in individuals older than 50 years. The frequency of CRC in males (57.2%) was slightly higher than in females (42,8%). The degree of cell differentiation of CRC is an important factor in determining the prognosis. In this study, the most common histopathological type was adenocarcinoma in 73 cases (94.8%). The frequency of immunohistochemical expression of cerb-B2, p53 and MSI markers in CRC individuals was 2.6%, 57.1% and 62.3%, respectively. The p53 marker was related to individuals age, while the cerb-B2 and MSI markers had no statistical association with the clinical and morphological parameters evaluated. In addition, tumor size was not related to age, degree of differentiation and lymphatic invasion. The expression of MSI had no significant association with the expression of p53 and cerb-B2, since these markers can work in different carcinogenic pathways. Thus, it was concluded that MSI expression was the most frequent among individuals with CRC in the state of Tocantins, while the p53 marker was related to the patient’s age.