Many patients who have high-risk colon polyps removed during a colonoscopy are failing to undergo recommended follow-up screenings for colorectal cancer, according to a study published in Cancer Epidemiology, Biomarkers & Prevention.
The most common type of polyps discovered during a colonoscopy are called adenomas, which have the potential to become cancerous, although most don’t. Patients who have high-risk polyps, such as a large adenoma (10 millimeters, or about 0.4 inches), three or more adenomas, or a type of polyp called villous adenoma, are at an increased risk of developing colon and rectal cancers (colorectal cancer). Clinical guidelines recommend that those patients have a follow-up, or surveillance, colonoscopy three years later.
But many patients aren’t getting their three-year surveillance screenings, according to the new study. Researchers tracked 6,909 patients ages 50 to 89 who either had a high-risk adenoma removed or had more than three adenomas removed at facilities in four regional health care systems. Those included Kaiser Permanente’s Northern California, Southern California, and Washington health care systems and the public Parkland Health & Hospital System in Dallas.
The researchers found that only 47 to 60 percent of those treated at one of three Kaiser Permanente hospitals returned for a surveillance screening within three and a half years. Even more disturbing: Only 18 percent of patients from the Parkland Health & Hospital System—which serves patients even if they don’t have insurance or the ability to pay—underwent follow-up screening. The patients most likely to get appropriate follow-up were between ages 60 and 74.
One reason for the different return rates between Kaiser facilities and Parkland might be the nature of the organizations and their patient populations (for example, different patient outreach protocols and insured vs. uninsured patients). But that still doesn’t account for the poor percentage of surveillance screenings overall.
The researchers suggested that if hospitals had protocols in place to remind patients of surveillance screenings, the follow-up rate might be higher.
An earlier study, published in JAMA in 2017, found that patients are also likely to delay follow-up colonoscopy after getting a positive result on a fecal immunochemical test (FIT), another screening test for colorectal cancer.
What you should do
Ask your doctor when your next colorectal cancer screening should be done. With some exceptions, guidelines recommend follow-up colonoscopies three years after removal of high-risk adenomas. If you have low-risk adenomas, you can wait five years until your next colonoscopy, or 10 years if no polyps are found.