Obesity and malnutrition – risk factors in prediagnostic and later phases of colorectal cance

Obesity and malnutrition are subjected to comprehensive studies as risk factors in the pathogenesis of colorectal cancer (CRC). Nevertheless, the most recent scientific evidence revealed that a number of issues associated with risk impact processes remain to be clarified. The aim of the current review is to discuss the action mechanisms of obesity and malnutrition, their effect in the prediagnosis and later phases of CRC, with emphasis on concomitant oxidative stress. The relationship obesity-CRC is considered in three aspects: low-grade inflammation and role of adipocytokines, development of metabolic syndrome, lipid peroxidation and oxidative stress. Malnutrition effect is discussed in two aspects – metabolic dysregulation and oxidative stress. Data are presented on the specificity of action of the two risk factors referring to the periods of disease course. Oxidative stress is a characteristic indicator of obesity, malnutrition and CRC. This fact enables us to recommend its inclusion together with nutritional status indicators in CRC screening.