ABSTRACT
BACKGROUND: Colorectal cancer (CRC) has been described in the medical literature as resulting from many forms of interaction between lifestyle, genetics, and geographical origin. Genetically, the KRAS gene has a negative impact on the general survival and prognosis of patients when mutated. METHODS: This study was conducted in Brazil and included information about 60 patients with CRC stage III and IV examined at the Day Hospital Oncológica do Brasil, whose DNA was analyzed with the PCR-DNA method to determine the existence of a KRAS mutation. RESULTS: The results revealed that 18.3% of the individuals analyzed showed a KRAS mutation (24% of mutations were found in men and 14.3% in women), which is a smaller proportion than those found in other large studies across the globe. CONCLUSION: As our analysis is one of the very first published about this topic, more studies are necessary to understand the role of KRAS mutations and the associated variables in populations such as that of the Amazon region.