An at-home test for colon cancer is as reliable as the traditional screening, health experts say, and more agreeable.
Most Americans who are due for a colon cancer screening will receive a postcard or a call — or prompting during a doctor’s visit — to remind them that it’s time to schedule a colonoscopy.
But at big health care systems like Kaiser Permanente or the federal Veterans Health Administration, the process has changed. Patients who should be screened regularly (age 50 to 75) and who are of average risk, get a letter telling them about a home test kit arriving by mail.
It’s a FIT, which stands for fecal immunochemical test. The small cardboard mailer contains equipment and instructions for taking a stool sample and returning the test to a lab, to detect microscopic amounts of blood. A week or so later, the results show up on an online patient portal.
Five to 6 percent of patients will have a positive test and need to schedule a follow-up colonoscopy. But the great majority are finished with colon cancer screening for the year — no uncomfortable prep, no need to skip work or find someone to drive them home after anesthesia, no colonoscopy.
Last spring, when the coronavirus pandemic closed many medical facilities and postponed nonemergency procedures, this approach suddenly looked even more desirable.
“We know that from March to May, colon cancer screenings fell by about 90 percent,” said Dr. Rachel Issaka, a gastroenterologist at the University of Washington and the Fred Hutchinson Cancer Research Center. Although testing has resumed, she said, “we’re still not back to where we were.”
Yet colon cancer represents the third-highest cause of cancer deaths, after lung cancer and, tied for second place, breast and prostate cancer. Unlike those, colon cancer can be prevented with early detection.
With many older adults trying to avoid hospitals and surgical centers, even as their risk of colon cancer rises with age, an at-home test provides an alternative to colonoscopy — one that is both safer, with a lower risk of complications and Covid-19 exposure, and does as good a job.
“If your doctor tells you a colonoscopy is better, that’s not accurate,” said Dr. Alex Krist, chairman of the U.S. Preventive Services Task Force, an independent expert panel that reviews evidence and issues recommendations. “The data show the tests are equally effective at saving lives.”
The Task Force is updating its guidelines for colon cancer screening and this year will likely recommend lowering the age at which it should begin, to 45. But the recommendations on the upper end will remain unchanged: Based on strong evidence, adults up to age 75 should be screened regularly.
Beyond that age, the disadvantages begin to mount. The Task Force says the benefit of screening 76- to 85-year-olds is small, and that the decision should be an individual one, reached in consultation with a doctor.
Colon cancer develops slowly, explained Dr. James Goodwin, a geriatrician and researcher at the University of Texas Medical Branch in Galveston. Patients at older ages, who typically contend with several other diseases, may not live long enough to benefit. “You cause more harm than good,” Dr. Goodwin said.
The advice to stop screening isn’t always popular with patients. “People don’t like to hear about not living very long,” he said. But with colonoscopy, he noted, “you go through an unpleasant experience — or an unpleasant experience followed by an unpleasant diagnosis and unpleasant treatment — for something that, if you’d never known about it, wouldn’t cause you harm.”
Even if a test eventually finds colon cancer, surgery plus chemotherapy, the standard treatment, could itself endanger a frail older person. “I would be heavily biased against anyone getting a screening, of any sort, over age 80,” Dr. Goodwin said.
Although Americans still rely mostly on colonoscopy, his research has shown that for many older people, that test is overused, either because of the patients’ ages or because they are tested too frequently.
Yet screening is simultaneously underused. In 2018, according to the Centers for Disease Control and Prevention, only about 70 percent of adults were up-to-date on colorectal cancer testing. About one-fifth of those 65 to 75 had not been screened as recommended. Among those 50 to 65, where lack of Medicare or other insurance probably contributed, only about 63 percent were appropriately screened.
The Task Force has found several kinds of screening tests effective, but the ones used most for people at average risk are colonoscopy, at a recommended 10-year interval, or FIT annually.
A newer entry, an at-home test sold under the brand name Cologuard that detects blood and cancer biomarkers in stool, may be used every three years, but a study found it to be less effective than most other methods and far more expensive than FIT.
When screening is recommended, how does FIT stack up against colonoscopy?
Higher-risk patients — including those who have had colon cancer or parents or siblings with colon cancer, those with inflammatory bowel disorders like Crohn’s disease, and those who have had abnormal previous tests, including multiple or large polyps — should seek out a colonoscopy, often on an accelerated schedule. The procedure involves inserting a viewing instrument through the anus to directly visualize an anesthetized patient’s colon.
A colonoscopy offers one distinct advantage: if the gastroenterologist spots polyps, growths that over time could become cancerous (although most don’t), these can be removed immediately. “You’re preventing cancer, snipping out the things that could lead to cancer,” Dr. Goodwin said. After a negative colonoscopy, patients don’t need another for a decade.
But the procedure’s complications increase with age, although they remain low; the most serious, a perforated colon, requires hospitalization. Cleaning out the bowel on the day before the procedure, in preparation, is disruptive and disagreeable, and Dr. Goodwin notes that older patients sometimes experience cycles of diarrhea and constipation for weeks afterward.
Rural residents may find traveling to a facility difficult. The use of anesthesia means that every patient needs someone to drive or escort them home afterward. The prospect of spending two to four hours in a facility, even one using rigorous safety measures, will cause some older adults to postpone testing because of Covid-19 fears.
The FIT, which is far more widely used in other countries, avoids many of those difficulties. A marked improvement over earlier at-home stool tests, it requires a sample from one day instead of samples from three, and imposes no food or drug restrictions. A positive result still calls for a colonoscopy, but the great majority of patients avoid that outcome.
Why do so many Americans still undergo colonoscopies, then? “There’s a large financial incentive for people who do colonoscopies to do colonoscopies,” Dr. Goodwin said, so patients may not hear much about the alternatives.
“Many of my own patients are surprised to learn that there’s another way,” said Dr. Krist, also a family physician at Virginia Commonwealth University. “As they age, they want less invasive methods” and may be happy to switch.
Wider adoption of FIT could also save patients and insurers, notably Medicare, a boatload. The home test, which is available through several manufacturers, generally costs less than $20; a colonoscopy can easily exceed $1,000.
Moreover, with personalized messages to patients and follow-up reminders to return the kit, FIT use can result in more people being screened. That could prove important when the Preventive Services Task Force lowers the recommended age to 45, which would add 22 million Americans to the list of people advised to undergo colon cancer screening. Their needs, plus a backlog of patients who postponed tests during the pandemic, could swamp gastroenterology practices.
“If a provider doesn’t bring up” the possibility of an at-home test, Dr. Issaka said, “patients should feel empowered to ask about it.” Colon cancer screenings, of any type, “are considered non-urgent,” she said. “But they’re not optional.”
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