Ewa Arnold: Graceful Health: Time for a colon cancer screening test? Here are some of the options
Did you know that colon cancer is the second leading cause of cancer deaths in the U.S.? The disease affects both men and women, mainly but not exclusively those over age 50. Despite this dire morbidity statistic, it's important to remember that colon cancer is highly treatable — if discovered early. That's why it's so important to have your colon screening tests on schedule.
March is National Colorectal Cancer Awareness Month, so this is a good time to revisit the topic.
The Centers for Disease Control and Prevention (CDC) recommends that, beginning at age 50, adults have regular screenings until at least age 75. Colon cancers generally develop slowly. After age 75, you should discuss the alternatives with your provider.
Despite the notoriously uncomfortable preparation required, the gold standard for colon screening is still the colonoscopy.
Colonoscopy is the most thorough test available. By inserting a long, thin, flexible lighted tube, the doctor can visually examine the whole system — the upper and lower colon and rectum. Colonoscopy also has the benefit of being curative. During the procedure, the doctor can remove any precancerous polyps found. These are then tested to determine a diagnosis and treatment. The sooner these polyps are found, the better one's chance of surviving.
While there's no denying that the preparation for a colonoscopy test is uncomfortable at best, it is worth the effort. Generally the preparation involves abstaining from solid food for the day prior to the test, while drinking a large quantity of laxatives to empty and clean the bowels. This is necessary so that nothing obscures the doctor's view. Good thing most people have to do this only once every 10 years!
Usually, the patient is partially sedated during the test, which generally lasts 20-30 minutes. Because the sedation wears off slowly, the patient needs a ride home. The most common side-effect is some bloating and painful gas for a day or so, because air is inserted into the bowels during the test.
The colonoscopy is the gold standard and is the recommended test for anyone with an increased risk of colon cancer, including those with a family history of the disease, and those for whom pre-cancerous polyps have already been found.
For others, there are several other choices for colorectal cancer screening. I sometimes prescribe the fecal immunochemical test (FIT) test, used to check stool samples for blood. The advantage of this test is that there is no preparation and it can be performed in the privacy and comfort of the patient's own home. The test is usually repeated annually. One disadvantage of this test is that it is not sensitive enough to find precancerous polyps. Also, this test has a tendency to produce false positives. Blood could be present in feces for a variety of reasons (small abrasions and tears from hemorrhoids or constipation, for example). The FIT test cannot determine the source of the bleeding, only the presence of blood, so if any blood at all is found, the next step is to have a colonoscopy.
There are several other tests that can be used for colon cancer screening. Increasingly, patients are choosing the stool DNA test. Cologuard is one tradename for this test. The test is similar to the FIT test from the patient's point of view. In this case, though, the lab looks not for blood, but for altered DNA that might signal the presence of cancer. The test is fairly new, so there are no long-time studies regarding its effectiveness, but so far, results look promising.
Less common but also are available when particular circumstances warrant are the virtual colonoscopy (conducted with a CT scanner, it produces 3-D images of the colons and the rectum; it requires preparation similar to the colonoscopy, but no sedation is required during the test), and the Flexible sigmoidoscopy (similar to the colonoscopy in that a thin lighted instrument is inserted, but with the disadvantage that it can examine only part of the lower colon and the rectum; less preparation is required of the patient).
Ultimately, the best way to determine which test is right for you is to have a discussion with your medical provider. Talk about your health history, and discuss frankly your willingness to follow through on the requirements of the test you choose.
The most important thing is to do it. Having a colon cancer screening test may not be fun, but it's a test that can literally save your life. Remember, the earlier colon cancer is detected, the easier it is to treat. If it's your time for the test, commit yourself to getting it scheduled this month.
Dr. Ewa Arnold is a graduate of the University of Guelph in Ontario, Canada, and Jagiellonian University in Krakow, Poland. She completed her family practice residency at the UVM College of Medicine in Burlington.
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