You may have your father's eyes, your children may have your red hair, but families can also pass on genetic diseases. These diseases are the result of defects or changes in the DNA - the material in almost all of your cells that determines what traits are inherited by children from their parents. These tests can be important because even though this cancer is the second most deadly cancer in America, it's also the only cancer that can be almost completely prevented.
Colorectal cancer strikes the colon and the rectum, both parts of the large intestine.
Digested food passes from the colon into the rectum, which is the last six to eight inches of the large intestine, where it is passed from the body. Almost all cases of colon cancer start with small growths called polyps on the inside lininng of the colon. These polyps are either rounded bumps or shaped like mushrooms. If doctors find and remove them before that, the cancer can be prevented. With DNA tests, doctors can identify which families will have a higher incidence of colon cancer.