People who had high-risk polyps removed and waited 5 years for their first follow-up colonoscopy developed colon cancer no more often than people checked at 3 years, according to the EPoS II trial published this week in the New England Journal of Medicine. After 5 years, 0.77% of the 5-year group and 0.82% of the 3-year group had colorectal cancer.
If you are booked for a 3-year follow-up after high-risk polyps, this trial gives you a reasonable question to bring to your gastroenterologist: is a 5-year interval sensible for me? It does not give you permission to skip or push back a scope on your own. And it has nothing to say about symptoms. Rectal bleeding or a change in bowel habits still needs to be checked now, not at your next scheduled date.
Key takeaways
- In 10,799 patients across eight European countries, starting follow-up at 5 years instead of 3 did not lead to more colon cancer by year 5.
- This is an early look at a 10-year trial, and current guidelines still call for 3 years.
What the study found
The researchers randomly assigned people who had high-risk adenomas removed to a first follow-up colonoscopy at either 3 years or 5 years. “High-risk” meant at least one adenoma 10 mm or larger, one with high-grade dysplasia or villous growth, or 3 to 10 adenomas of any kind. The 5-year group had 5,398 people and the 3-year group had 5,401.
In plain numbers, colon cancer showed up in about 8 of every 1,000 people in both groups by year 5 (0.77% vs 0.82%). That is a difference of 0.05 percentage points, roughly 1 fewer case per 2,000 people in the group that waited longer. Nobody should read that as a benefit of waiting. It is a tie.
The trial was built to show the 5-year strategy was “noninferior,” meaning not meaningfully worse. The researchers set the line at 0.7 percentage points. The worst case the data could not rule out was 0.68 percentage points, just under that line, so the test was passed.
Cancers found in the two groups did not appear to differ much in stage. Five people died of colorectal cancer: 3 (0.06%) in the 5-year group and 2 (0.04%) in the 3-year group.
Dr. Kumar’s take
The headline result is real, but three details matter.
First, this is an interim analysis. The trial’s main goal is colon cancer at 10 years, and these are results after about 5.5 years of follow-up. Long follow-up can change the story of a trial, as it did with 20 years of Women’s Health Initiative data on HRT and breast cancer.
Second, the 3-year group also had a colonoscopy at 5 years. So by year 5, both groups had been scoped. The question this report answers is whether skipping the extra year-3 exam changed cancer rates by year 5. What happens after that is still unknown.
Third, the safety margin is wide compared with the risk itself. A cancer rate under 1% was tested against an allowed gap of 0.7 percentage points. In natural frequencies, the data still fit with up to about 7 extra cancers per 1,000 people who wait. The actual result was a tie, which is reassuring, but “passed the noninferiority test” is not the same as “proven equally safe forever.”
None of this takes away from the size or quality of the trial. It is large and randomized, and it asks a practical question. Fewer scopes means fewer bowel preps, fewer sedations, and more capacity for people who need a first colonoscopy. As the researchers point out, all of this depends on the first colonoscopy finding the polyps and fully removing them.
What it means for you
- If you had high-risk polyps removed and are due at 3 years: Ask your gastroenterologist whether 5 years is reasonable for you. Bring your pathology report. The answer depends on what was found, how many polyps, and how completely they were removed.
- Do not cancel a booked colonoscopy on your own because of this study. Current guidelines still recommend 3 years.
- Symptoms override schedules. Rectal bleeding, black stools, a lasting change in bowel habits, or unexplained weight loss or anemia should be checked promptly, whatever interval you are on.
- Never had a colonoscopy? This trial is about follow-up after polyp removal. It does not change screening advice for anyone else.