Analysis of RAS-mutation and microbiom of patients with colorectal cancer

Abstract

© 2018, Advanced Scientific Research. All rights reserved. In Russia, over the past 50 years, the number of primary diseases with colorectal cancer (CRC) has increased 7-fold; today in Tatarstan every 42nd resident of the republic is registered as an oncological patient. Analysis of patients with diagnosed rectal cancer in the RT revealed that the overall incidence of KRAS mutations was 33%, 68% of cases with mutations in the 12th codon, 33% of the detected mutant KRASs are homoduplexes. Patients older than 60 years carry the mutant KRAS, which nullifies the effectiveness of Epidermal Growth Factor receptor (EFGR) inhibitors, in only 10% of cases. In the group of patients younger than 50 years, KRAS mutations were found in 58.3% of cases. The microbial profile of the biopsy specimens revealed a tendency for phylum Bacteroides and Enterobacteriaceae to predominate on intact epithelium and replace them with tumor genera Faecalibacterium, Streptococcus and Fusobacterium on tumor. The taxonomic structure of bacterial communities of biopsy specimens is diverse; in tumor tissue, diversity can both decrease and increase. The representation of the Prevotella genus in the epithelium with the mutant KRAS gene was increased in 50% of cases. Expanding the spectrum of molecular targets in the epithelium and intestinal microbiome should ensure the effectiveness of personified antitumor therapy.