Colorectal cancer is the third most common type of cancer and the second leading cause of cancer death among American adults. If it is detected early, before it spreads, colorectal cancer can be treated effectively. That’s why gastroenterologists are adamant about the importance of screening for this condition. Currently about 67 percent of eligible people have gone through a screening procedure. The gold standard is colonoscopy, in which a specialist finds and removes growths called polyps. He or she does this during a visual inspection of the lining of the colon. Many people find preparation for colonoscopy (colon cleansing) arduous. In addition, though the cost is usually covered by insurance, some object to the price. Are there viable alternatives to colonoscopy?
Seeking Alternatives to Colonoscopy:
Q. More than a decade ago, I had a colonoscopy. Not liking that procedure, I chose to use Cologuard at the usual recommended 10-year retest. Both times, the tests were negative. Now, three years later, I asked my doctor to give me a referral to a gastroenterologist for my next Cologuard. She hemmed and hawed about the use of Cologuard, finally stating that her medical group is no longer using Cologuard because of “the inability to correlate the information provided by that test with the outcomes of a colonoscopy.”
My only option if I want a non-invasive screening would be to use an immunochemical fecal occult blood test yearly. Is this test reliable?
A. People at high risk of colorectal cancer due to family history or previous polyps should have regular colonoscopies. That is because the doctor removes any polyp he or she finds during the procedure.
How Reliable Are FIT and Cologuard?
Individuals at average or low risk may utilize one of the alternatives to colonoscopy. They could benefit from an FIT (fecal immunochemical test). This over-the-counter home test reveals blood in the stool. A study published in the Annals of Internal Medicine (Feb. 26, 2019) showed that such tests detect up to 80 percent of cancers.
A colonoscopy detects up to 95 percent of colorectal cancers. FIT can be adjusted to pick up 91 percent of tumors, but it will also flag false positive cases. Anyone who tests positive on a FIT will need a follow-up colonoscopy.
Cologuard, based on detecting DNA from polyps, can also produce false positives (New England Journal of Medicine, April 3, 2014).
According to an early analysis of this technology,
“In asymptomatic persons at average risk for colorectal cancer, multitarget stool DNA testing detected significantly more cancers than did FIT but had more false positive results.”
One difference you should note: you should complete FIT screening every year. The doctors who developed Cologuard recommend that you use it every three years. We don’t know exactly why your doctor’s group has soured on Cologuard, as it seems that such alternatives to colonoscopy are viable for those who are not at high risk.