It also may spread to nearby lymph nodes or to the liver. Less frequently it can spread through the blood stream to the lungs or bone. Several environmental factors are thought to add to the risk of developing colorectal cancer. A diet high in saturated fat and low in fiber has been previously identified as possibly increasing risk, however recent research has not confirmed this. Rather, maintenance of lean body weight throughout life has now been shown as important for prevention.
Regular exercise appears to lower chances of getting colon and other cancers.
A small percent of colorectal cancers are related to a hereditary condition known as familial polyposis, which is characterized by the development of numerous polyps in childhood and adolescents. Overtime, many of these individuals will develop colon cancer. Genetic factors also have been linked to colorectal cancer. Mutations in the k-ras gene from environmental causes are found in 50 percent of all people with colorectal adenomas and cancers. Defective tumor suppressor genes may be responsible for up to two-thirds of hereditary colon cancer.