Colon cancer is the second leading cause of cancer deaths in the United States, and in most cases, it develops from abnormal precancerous growths called polyps.
About 60% of these deaths can be prevented by routine screenings beginning at age 50. The "gold standard" of colorectal screening methods is the colonoscopy. During this test, an experienced gastroenterologist can detect and remove any polyps found in the colon and rectum, then test them for cancer.
What are polyps?
Polyps are growths on the lining of the colon and rectum. They may be flat or project from the colon wall. Some polyps may increase a person’s risk of developing colorectal cancer, but not all polyps become cancerous.
There are three main kinds of polyps found in the colon:
- Adenomas, which give rise to most colorectal cancers
- Hyperplastic polyps, which are generally benign but may have the potential to become malignant
- Psuedopolyps, which are areas of the colon lining inflamed by a severe attack of colitis, most often from inflammatory bowel disease
Who is at risk?
Age is the primary risk factor for developing polyps that become malignant. Family history and genetics are also thought to play a role. You may be at risk for developing colon polyps if you are:
- Age 50 or older
- Had polyps previously
- Are related to someone who has had polyps
- Are related to someone who has had colon cancer
- Eat lots of fatty foods
- Drink alcohol
Men are more likely than women to develop colorectal polyps, yet the incidence of colorectal cancer is about equal between the genders. Recent studies show that African Americans, Asians and Latinos are more likely to be diagnosed with colorectal cancer than whites. But these ethnic groups are half as likely to be screened for colorectal polyps as whites.
Heavy cigarette smoking has been linked to a two to three-fold higher risk of developing precancerous colorectal polyps. Being overweight is also linked to a higher incidence of polyps. Both of these risk factors can be modified by behavioral changes.
Do polyps produce symptoms?
Most people don't know they have a colorectal polyp until a doctor finds it during a regular checkup or in tests for something else. Those who do experience symptoms may notice:
- Diarrhea or constipation lasting more than a week
- Bleeding from the anus
- Blood that can appear either red or black in the stool
Bleeding in the stool is not normal. You should see your doctor immediately.
How do you test for colon polyps?
There are several methods, including:
This procedure involves an infusion of a chalky liquid introduced through the rectum to allow X-ray imaging of the large intestine. The barium creates a contrast that makes dark polyps easy to see against the white liquid, unless they are small or flat lesions. A subsequent procedure is required to biopsy or remove the polyps. These are rarely used for screening purposes.
- Computerized tomography (CT) scan
Known as a virtual colonoscopy, this procedure involves the insertion of a thin flexible tube into the rectum. The tube is used to push air into the colon and rectum to improve the images that are taken. The procedure is quick but if polyps are found, a second procedure is required to remove them.
A thin, flexible tube equipped with a light and camera is inserted into the rectum, enabling the physician to examine the rectum and distal (sigmoid) colon to detect and potentially remove any polyps. However, this procedure is limited to screening the last third of the large intestine.
Colonoscopy is considered the gold standard for polyp detection because it is the only screening method that allows your physician to detect and remove polyps along the entire large intestine. A flexible tube with a camera is inserted into the rectum to inspect the entire large intestine. The tube also has a tool to remove polyps during the procedure. Sedation is typically required for this outpatient procedure, which is usually preceded by a day of preparation to void the bowels completely.
Other screening tools include a laboratory analysis of a stool sample for blood or signs of cancer and new imaging technologies such as high-magnification chromoendoscopy and narrow band imaging.
How are polyps treated?
Polyps are usually removed during a sigmoidoscopy or colonoscopy with a wire loop that cuts and cauterizes at the same time, a procedure called a polypectomy. Very large or difficult-to-reach polyps may require separate laparoscopic surgery.
The polyps are tested for signs of cancer. Even if no cancer is detected, your doctor may recommend regular screening tests because the likelihood of new polyps forming is heightened.
Can I prevent colon polyps?
There is no known way to preventing polyps from forming. However, the National Digestive Diseases Information Clearinghouse recommends the following things you can do to lower your risk:
- Eat more fruits, vegetables and whole grains
- Eat less saturated fats
- Limit alcoholic beverages
- Quit smoking
- Exercise regularly each week
- Lose excess weight
Some studies suggest that adding calcium to your diet can lower the risk of developing colorectal polyps. Calcium-rich foods include broccoli, kale, yogurt, milk and cheese. Vitamin D also helps the body absorb calcium.
Regular aspirin also may reduce the risk of polyps, but it can increase the risk of gastrointestinal bleeding.
It’s important to consult your physician before taking any medication. Your physician may also recommend regular colonoscopies, especially after age 50.
Questions? Call us at 888-717-4463.