Inestabilidad de los microsatélites en cáncer colo-rectal y su distribución de acuerdo a factores pronósticos en SOLCA Cuenca 2004-2014

Abstract

Worldwide, colorectal cancer is the third most common neoplasm in men and the second in women. Tumorigenesis pathways allow us to subclassify patients and protocolize treatments. The microsatellite instability constitutes one of these pathways; it is present in a 15% to 20% in colorectal carcinoma; its presence is associated with a better prognosis. Objective: To determine the frequency of microsatellite instability and its distribution according to prognostic factors in biopsies of patients with colorectal cancer in the Solca-Cuenca Cancer Institute during the period 2004-2014. Method: It is an observational, analytical study. About 240 patients with colorectal cancer were studied, they were diagnosed in the Pathology Department of the Cuenca Cancer Institute and who had their biopsy material where the immunohistochemical techniques were performed with 4 markers MLH1, MSH2, MSH6, and PMS2. Results: The 37.9% corresponded to men and 62.1% to women. The average age was 66.2 years. The 58.75% (n = 141) had localization in the colon. A lack of protein expression was observed in 24.2% (58 patients). Regarding to proteins, 68.96% (40 cases) were MLH1 / PMS2; 1.72% (1 case) MSH2 / MSH6. About the cases that did not express the proteins, 87.93% were located in the colon; 79.3% were adenocarcinoma; 58.6% were moderate grade and 37.9% were stage II. In the bivariate analysis, a statistically significant association was established between microsatellite instability with tumor location (OR 7.4, CI 3.2-17) and degree of differentiation (OR 2.8, CI 1.5-5 .4). Conclusions: The protocolized use is recommended within the treatment of colorectal cancer.