Risk Factors and Carcinogenesis of Colorectal Cancer

Aim: to present current research data on the epidemiology and carcinogenesis of colorectal cancer. Key points. Colorectal cancer (CRC) ranks third in the incidence of malignant tumors in most countries of the world, including Russia. At the same time, the incidence rate continues to grow both globally and in Russia, where CRC accounts for 12.2 % of the total oncological incidence. It is possible to stop the growth and achieve a significant reduction in the incidence of CRC only by identifying proven causes and risk factors for CRC and introducing effective measures for its prevention into the healthcare system. The review includes three sections of research: 1) CRC prevalence in populations and the dynamics of CRC incidence; 2) causes and modifiable and non-modifiable risk factors of CRC; 3) mechanisms of CRC carcinogenesis. The majority of CRC cases, 90 to 95 %, are sporadic and largely due to a combination of modifiable environmental and lifestyle risk factors, such as certain dietary characteristics, gut microbiota, body weight, physical activity, alcohol consumption, tobacco use, precancerous diseases of the colon and rectum, and the level of knowledge about the causes of CRC and measures to prevent them. It is estimated that approximately 30 % of CRC cases are due to varying degrees of genetic predisposition or non-modifiable risk factors, but only 5 % of all CRC cases develop in the context of known genetic syndromes that are caused by a specific germline mutation. Conclusion. The information presented in the review on proven modifiable and non-modifiable risk factors for CRC and the mechanisms of their participation in CRC carcinogenesis will contribute to the development of effective methods for the prevention of CRC and their implementation in practical health care.