THE ROLE OF THE INTESTINAL MICROBIOTA IN THE COLON CANCER DIAGNOSTICS

Objective. To determine the composition of the the parietal microflora of the colon under the condition of a tumor process and to assess the possibility of using these data from this study in the diagnosis of the colon cancer. Methods. The main group included patients (n=75) operated on in the Trans-Baikal Regional Oncology Center for the colon cancer. Among them are 38 men and 37 women aged 20 to 75 years. Control group consisted of 25 patients. The material of the main group, biopsies of tumor tissue and visually unchanged colon mucosa was taken intraoperatively during tumor removal. In patients of the control group, the material was taken during the colonoscopy. process. The detection of Helicobacter pylori in the biopsy of the mucous membrane was carried out by determining the urease activity, as well as by the method of polymerase chain reaction. The composition of the intestinal microbiota was determined by the bacteriological method. Results. As a result of comparison of the colon microbiota of the cancer patients and the control group, statistically significant differences in the quantitative composition of Lactobacillus spp., Bifidobacterium spp., Bacteroides spp., Clostridium spp., Enterococcus spp., E. coli (typical), E. coli (lactose-negative), Enterobacteriaceae, Staphylococcus spp. (CNS), Candida spp. were revealed. Moreover, a clear tendency of changes in the level of certain microorganisms (Bifidobacterium spp., E. coli (typical), Clostridium sp.) was detected when comparing the mucous membrane of a healthy person, unchanged mucous membrane of a patient with colorectal cancer, tumor tissue. A statistically significant dependence of the level of microorganisms on the sex of a patient, as well as the form of tumor growth, was revealed. Conclusion. Thus, a reliable correlation between the clinical and morphological characterization of the colon malignant tumor and the composition of the intestinal microbiota has been revealed. The microbiological features established within in the course of the study, which arise precisely under the conditions of colon cancer, can be used as an additional diagnostic marker in the diagnosis of a malignant process. What this paper adds It was found that thequantitative composition of the intestinal microbiota during the transformation into mucous and malignant tumor tissue in colon cancer and the correlation of specific microorganisms with the patient’s gender and the form of tumor growth. The state of the intestinal microbiota may represent a promising diagnostic marker for the detection of a malignant tumor.