Colorectal Cancer Colorectal cancer is a malignancy that starts in the colon or the rectum. These cancers can also be referred to separately as colon cancer or rectal cancer, depending on where they start.
Colon cancer and rectal cancer have many features in common. There are some differences in treatment. Most colorectal cancers develop slowly over several years. Before a cancer develops, a growth of tissue or tumor usually begins as a non-cancerous polyp on the inner lining of the colon or rectum. A polyp is a benign, non-cancerous tumor.
Some polyps can change into cancer but not all do. The chance of changing into a cancer depends upon the kind of polyp. Adenomatous polyps (adenomas) are polyps that can change into cancer. Hyperplastic polyps and inflammatory polyps, in general, are not pre-cancerous.
There are several different kinds of cancer that can arise in the colon and rectum including: Adenocarcinomas, Carcinoids, Gastrointestinal stromal tumors (GISTs), Lymphomas, and Sarcomas.
Colorectal cancers are usually treated with surgery and sometimes chemotherapy, radiation therapy, and targeted therapy. For more information look here: http://www.cancer.org/cancer/colonandrectumcancer/