Colorectal cancers arise from dysplastic adenomatous polyps in the majority of cases. The early event is a mutation of APC (adenomatous polyposis gene), which was first discovered in individuals with familial adenomatous polyposis (FAP). In addition to mutations, epigenetic events such as abnormal DNA methylation can also cause silencing of tumor suppressor genes or activation of oncogenes.
Disease statistics in Singapore: Most colorectal cancers are diagnosed at Stage two or higher. The age-standardized 5-year survival rates for colorectal cancer have increased from 25.3 and 26.4% to 57.0 and 58.9% in males and females in the periods of 1973–77 and 2003–07.
Drugs that target specific defects that allow cancer cells to grow are available to people with advanced colon cancer, including bevacizumab (Avastin), cetuximab (Erbitux), panitumumab (Vectibix) and regorafenib (Stivarga). Targeted drugs can be given along with chemotherapy or alone. Eating dried plums positively affects bacteria in the gut, which helps lower risks of colon cancer. Radiation promotes colorectal cancer initiation and progression by inducing senescence-associated inflammatory responses.