The American Cancer Society estimates in 2014 there will be 96,830 new cases of colon cancer and 40,000 new cases of rectal cancer1. The good news is colon cancer is highly curable when found and treated in the early stages. That's why a colon cancer screening test, such as colonoscopy, is essential for men and women aged 50 or older, those with a family history of colorectal cancer, and African Americans. In fact, in many cases, early detection of polyps (growths in the colon) can prevent colon cancer altogether; the growths can be removed before they have a chance to turn into cancer2.
Cancer screenings are used to find signs of cancer when no cancer symptoms are present. There are two general types of colorectal cancer screening tests3:
- Looks for both cancer and polyps. This is the preferred screening method, if available, because it is more comprehensive. These tests can examine the insides of the colon to look for signs of cancer. Examples of this type of screening include colonoscopy, sigmoidoscopy, double-contrast barium enema and CT colonography (virtual colonoscopy).
- Looks for cancer only. These tests look for blood in the stool and can often be performed at home. Although less invasive, these tests are not good at detecting polyps. A positive result requires a follow-up colonoscopy or other imaging procedure. Examples include fetal occult blood test (FOBT) and fetal immunochemical test (FIT).
Common colon cancer screening tests include the following:
During a colonoscopy, a doctor looks at the entire colon and rectum with a colonoscope, a lighted tube with a video camera on one end. If anything suspicious is found, such as polyps, a special wire loop can be passed through the tube to remove them for further analysis. Patients need to prep prior to a colonoscopy to clean out the colon. This may involve taking laxatives or enemas, and dietary restrictions (for example, drinking only clear liquids). Patients are sedated for a colonoscopy and may be required to have someone else drive them home. Colonoscopy is a generally safe outpatient procedure that can be done at your physician's office in about 30 minutes.
During this test, a flexible lighted tube with a video camera on one end is inserted in the rectum to look at the rectum and part of the colon (sigmoid). Patients need to prep beforehand by drinking a liquid/clear diet or using enemas or other means to clean out the colon. The procedure takes about 10-20 minutes and should not be painful (although there may be some discomfort). Sedation is usually not needed. If a polyp is found, it may be removed and sent to a lab for further testing. If the polyp is pre-cancerous or cancerous, a colonoscopy will be needed to check the rest of the colon for polyps or cancer.
Also known as air-contrast barium enema, this procedure is an x-ray of the lower gastrointestinal tract to look for abnormalities. A chalky substance called barium sulfate and air are pumped into the colon to expand it. X-ray pictures of the lining of the colon are taken in various positions. If polyps are found, a colonoscopy will likely be needed to remove them and check the colon completely.
A virtual colonoscopy test is an advanced version of a CT scan, or x-ray. A CT scanner rotates around your body, taking pictures, while you lie on a table. Computer programs then create 2-dimensional images and a 3-dimensional "fly-through" view of the inside of the colon and rectum. This test is less invasive than a traditional colonoscopy, can be done quickly (about 10 minutes) and does not require sedation. Like a regular colonoscopy, patients must prep for it by emptying the colon, and a tube is placed in the rectum to insert air to expand the colon. If polyps are seen in the scan, a colonoscopy will still be needed to remove them or explore the area more thoroughly.
Fetal occult blood test (FOBT) and fetal immunochemical test (FIT) are home-based tests used to detect blood in fecal matter, a possible indicator of colorectal cancer. Stool samples (usually one to three) are sent to a lab for analysis. These tests can detect signs of cancer, and are not meant to diagnose colorectal cancer. A positive blood test should be followed up with a colonoscopy by a physician to look for cancerous polyps.
Lifestyle prevention tips
Cancer and nutrition experts say approximately 50 percent of colorectal cancers are preventable by combining a diet that includes fiber with daily physical activity and weight management4. Try these diet and nutrition tips to protect yourself from colon cancer:
- Eat more dietary fiber. Just 10g of fiber a day can reduce your risk for colorectal cancer by 10%.
- Cut calories to reduce excess abdominal fat. Belly fat is linked to changes in insulin and increased inflammation.
- Drink alcohol in moderation. More than 1 drink for women or 2 drinks for men per day increases colon cancer risk by 14%.
- Limit processed and red meats. Try fish and meatless meals that include beans for protein.
- Add cancer-fighting foods to your diet: Garlic, calcium-rich foods (milk), deep green/cruciferous veggies, red and orange fruits.
Schedule a colonoscopy
Community's gastroenterologists and colorectal specialists are experts in performing colonoscopy to check for colon cancer. Call 800-777-7775 today to schedule your colonoscopy and know your risk.