Cancer (cancer), is not a specific disease, it contains many types. But all cancers start when some cells in the body grow out of control. The continued growth of cancer cells can crowd out normal cells, making it difficult for the body to work properly. Cancer can develop anywhere in the body, such as in the breast, lungs, colon and even in the blood. The presence of cancer cells in the colon and rectum is called colorectal or colorectal cancer. Cancer cells can spread to other parts of the body. For example, cancer cells in the colon can travel to the liver and grow there. When cancer cells spread to other places, it is called metastasis. Cancer is usually named after the place where it occurs. So when colon cancer spreads to the liver or other parts of the body, it is still called colon cancer and not liver cancer. In most cases, colon and rectal cancers grow slowly over many years, and we now know that most cancers begin as polyps. Removing a polyp-like early can prevent it from becoming cancerous.