1. What is colorectal cancer?
Colorectal cancer begins in the cells of the colon or the rectum. Both the colon and the rectum are muscular tubes lined with glandular cells. The majority of colorectal cancers start in the glandular cells. The colon (known as the large bowel or intestine) joins the small intestine to the rectum. Cancer of the small intestine is very rare, so when you hear someone talk about bowel cancer, they usually mean colorectal cancer.
2. What causes colorectal cancer?
There is no single cause of colorectal cancer, but some factors appear to increase the risk of developing it, including:
Age (men and women) - particularly after 50
Polyps - small growths on the inner wall of the colon and rectum
Family history of colorectal cancer, benign colorectal polyps, inflammatory bowel disease (ulcerative colitis or Crohn's disease), or breast, ovarian or endometrial cancer
Lack of exercise
Heavy alcohol consumption
3. What are the symptoms of colorectal cancer?
Colorectal cancer is often referred to as the "silent killer" as there are usually no warning signs or symptoms, especially in its early stages.
Having the following symptoms does not mean that you actually have colorectal cancer, and in fact they could be caused by other problems. You need to talk to your doctor to be sure.
Blood in or on the stool (either bright red or very dark in colour)
A persistent change in normal bowel habits such as diarrhea, constipation or both for no apparent reason
Frequent or constant cramps, if they last for more than a few days
Stools that are narrower than usual
General stomach discomfort (bloating, fullness and/or cramps)
Frequent gas pains
Strong or continuing need to move your bowels, but with little stool
Feeling that the bowel does not empty completely
Weight loss for no apparent reason
Nausea and vomiting
4. How is colorectal cancer diagnosed?
After completing a physical examination (including a rectal exam) and discussing your overall health with you, your doctor may suspect colorectal cancer. A fecal occult blood test (FOBT) may also be taken to determine if there is blood in your stool. In addition, the FOBT test will show your doctor if there is bleeding in your colon. Bleeding may come from polyps.
Other tests to confirm colorectal cancer include a colonoscopy, a type of telescope that is used to examine the inside of the colon, a sigmoidoscopy, a test used to view the inside lining of the rectum and a part of the colon, or a barium enema which uses an x-ray to look at the colon.
5. When should you get screened for colorectal cancer?
The Canadian Cancer Society recommends that men and women 50 and older have a fecal occult blood test at least every two years. Individuals who fall into one of the high risk groups are those with a personal or family medical history of colorectal cancer, benign polyps, inflammatory bowel disease or breast, ovarian or endometiral cancer. These individuals should talk to their doctor about earlier screening.
6. Why is screening for colorectal cancer important?
Screening tests for colorectal cancer can save lives. It is treatable and often curable when detected early. In addition, testing will help to identify the grade of your cancer cells and what treatment action is required.
7. What treatment options are available for colorectal cancer?
Treatment for colorectal cancer depends mostly on the size, location, and extent of the tumor, as well as a person's overall health. Surgery to remove the tumor and radiation is the most common treatment in the earlier stages of the disease. Chemotherapy treatments such as Camptosar® are used in the later stages when the cancer has spread to other areas of the body.
Other chemotherapy treatments to fight cancers of the colon and rectum that have spread to other areas of the body include Xeloda® and 5-fluorouracil (5-FU).