Genetics in Colorectal Cancer

Abstract

Colorectal cancer are the third most commonly diagnosed form of cancer globally, which about 11% of all cancer diagnoses. Obesity, together with kind of sedentary lifestyle, red meat consumption, tobacco, and alcohol consumption are considered as predisposing factors of progression of CRC.  In the development of colorectal cancer, genetic factors having a role in its incidence. The hereditary type of colorectal cancer was divided into two types is polyposis and Lynch syndrome which have each and different mechanism and genetic pattern. Lynch syndrome contributes for 3–5% of CRC cases and is caused by a germline mutation in one of four genes associated with the DNA mismatch repair (MMR) system: MLH1, MSH2, MSH6, or PMS2. In polyposis, there are some types such as Familial Adenomatous Polyposis (FAP) which mostly caused by APC mutation, MYH-associated polyposis, and the rare hamartomatous polyposis syndromes. Genetic testing and better family history documentation can enable those with a hereditary predisposition for the neoplasm to take preventive measures. Some genetic testing can be used such as Microsatellite instability (MSI), immunohistochemistry (IHC), DNA sequencing and protein truncation that used for each type of hereditary colorectal cancer.