PERSONIFICATION OF EVALUATION OF INDIVIDUAL RISK OF COLORECTAL CANCER DEVELOPMENT IN OMSK REGION RESIDENTS

Abstract

Objective. The purpose of this study is to substantiate the assessment methodology with the Bayesian model of individual (personal) risk of developing colorectal cancer (CRC) in the population based on the Bayesian model for organizing primary prevention of the disease. Methods. Epidemiological studies (transverse and "case-control") were conducted to study the prevalence and significance of known risk factors in the development of CRC in the Omsk region population. Based on the analysis of literature data, 52 main known factors of development of colorectal cancer. To assess the probability of development of CRC in a particular participant with a certain combination of risk factors Bayes theorem was applied. Results. Risk factors for colorectal cancer were detected in 100 % of participants. Of the studied risk factors for the development of colorectal cancer among the participants in the study, residents of the Omsk region, confirmed their importance 22 factors. Based on the results of the survey, the participants in the study calculated conditional probability of detection of factors in the presence / absence of CRC. The established values of informativity and the chances were used to calculate the probability of development of CRC under a certain combination of risk factors. The results of the ROC analysis made it possible to determine the optimal operational characteristics of the proposed test with a decision threshold of 25 %o (area under the ROC curve - 0.89). In case of exceeding the threshold value, a specialist consultation can be recommended to the patient. Conclusions. Risk factors for development of colorectal cancer in Omsk region residents are 22 of 52 studied factors, of which the most significant are the presence of admixture of blood in the feces, false desires for stools, the presence of relatives of the first line with colorectal cancer, the presence of harmful substances in the workplace, the presence of polyps, hemorrhoids, cracks in the rectum, a preference for fatty foods. The proposed technique allows personifying the level of individual risk of colorectal cancer development taking into account regional prevalence, significance of risk factors, genotype and phenotypic features of a patient. The developed computer program for assessing the individual risk of developing colorectal cancer is valid and can be recommended for practical use.