Before you can understand how colon cancer can affect you, you must understand exactly what cancer is. Cancer is the umbrella name given to hundreds of diseases and disorders. Though talked about as lung cancer, breast cancer, colon cancers are many more, the disease does not really affect the organ but affects the cell of the organ. The title of the cancer comes from the organ affected. The colon, a major organ in your intestine, is made up of cells and when those cells become cancerous, colon cancer is diagnosed.