What is Colorectal Cancer?
Colorectal cancer is a cancer that is found in the colon or rectum, which make up the large intestine. It usually starts in the inner lining of the colon or rectum as growth or polyp. Although not all become cancerous, polyps can turn into cancer overtime. Precancerous polyps are also known as adenomatous polyps or adenomas that are larger than 1 cm. If cancer forms in one of these polyps, it can grow over time into the wall of the colon or rectum, which is made up of several layers. If colorectal cancer begins in the innermost layer, it can grow and spread outward to some or all of the other layers. Once these cancer cells are in the wall, they can grow into blood vessels or lymph vessels, which can move to nearby lymph nodes or other parts of the body, spreading the cancer.