Fig. 1

Genetic and environmental risk factors induce the CRC multistep process. The combination of genetic and environmental risk factors induces the CRC multistep process that determines the onset, progression, and metastasis of CRC. Approximately 30–40% of CRC have hereditary components (MLH1 and APC mutations: hereditary non-polyposis CRC and familial adenomatous polyposis, respectively), while the 60% of CRC arise sporadically as a result of a combination of somatic genetic mutation in CRC driver genes such as APC, KRAS, TP53 and BRAF or in DNA mismatch repair genes and epigenetic aberrations. Moreover, the environmental factors relating to lifestyle, particularly obesity, low physical activity, heavy consumption of alcohol and smoking, and nutritional factors, characterized by high consumption of red and processed meat and fatty foods, contribute overall to increase CRC risk