colon and rectum
The large intestine, which is part of the digestive system, is divided into two sections: the colon, which is the first four to five feet of the large intestine, and the rectum, which consists of the the last several inches. The colon is responsible for removing water and nutrients from digested food and turning it into stool, which is then passed to the rectum and eventually leaves the body through the anus.
Cancer that starts in either the colon or rectum can be referred to as colorectal cancer, or they also can be referred to as colon or rectal cancer separately, depending on where the cancer originates. It is estimated that there will be 141,000 new cases of colorectal cancer (102,000 colon and 39,000 rectal) diagnosed in 2010 alone.
Treatment for colorectal cancer largely depends on whether the cancer starts in the colon or the rectum, but typically consists of one or more of the following:
- Surgery
- The most common treatment for colorectal cancer is surgery, which can be performed by one of three methods: a colonoscopy, which uses a flexible tube that is inserted in the colon or rectum to remove small tumors; a laparoscopy, which uses a thin, lighted tube that is inserted through the abdomen to remove the tumor and area around it; and, open surgery, where a surgeon makes an incision in the abdomen to remove the cancer as well as some of the healthy surrounding area.
- Radiation Therapy
- Radiation therapy, the use of high energy rays to destroy cancer cells, is rarely used for the treatment of advanced colorectal cancers that have spread to other parts of the body, but it can be given in combination with chemotherapy before or after surgery. Additionally, radiation can be used to help to alleviate pain and other symptoms associated with colorectal cancer.
- Chemotherapy
- Given intravenously and by pill, chemotherapy works to kill the fast-growing cancer cells. Agents such as 5-fluorouracil, capecitabine, irinotecan, leucovorin and oxaliplatin are five most commonly used agents to treat colorectal cancer, and can be used alone or in combination with one another.
- Monoclonal Antibodies/Targeted Therapy
- Colorectal cancer also can be treated with a specially designed treatment called a monoclonal antibody, which also is called a targeted therapy. Monoclonal antibodies are designed to bind to specific proteins that are found on the surface of colorectal cancer cells in order to destroy them. Avastin, Erbitux and Vectibix are three monoclonal antibodies that can be used in combination with chemotherapy or after chemotherapy has stopped working to treat colorectal cancer.
