ABSTRACT
The process of development of colorectal cancer involves interactions between the genome (the genetic components) of the colorectal epithelial cell and its environment.1 These interactions are shown conceptually in Figure 3.1. Both inherent genetic and externally determined environmental factors are important causes of tumorigenesis (the process of development of a tumor).1,2
The colonic lumenal environment is complex, and is subject to great variability, largely due to diet. As a consequence, dietary lifestyle is very important.2 This accounts for the characteristic international epidemiology of this disease, where colorectal cancer is more common in countries that follow, or are moving towards, a Western dietary lifestyle.2
