Low-risk first follow-up needs no further checks
After the first follow-up colonoscopy, only patients with high-risk polyps again had higher colorectal cancer rates and likely needed a second follow-up.
*Retrospective cohort study; Level 2b (OCEBM).

Citation

Robbins EC, Wooldrage K, Rutter MD, Veitch AM, Cross AJ. Colorectal cancer incidence after the first surveillance colonoscopy and the need for ongoing surveillance: a retrospective, cohort analysis. Gut. 2025. doi:10.1136/gutjnl-2024-334242.

Background

Guidelines clearly define who should receive a first follow-up colonoscopy after polyp removal, but there is less evidence on whether more follow-up is needed after that first visit.

Patients

10,508 adults from 17 United Kingdom hospitals who had colonoscopy with polyp removal and at least one follow-up colonoscopy.

Intervention

Risk classification using polyp findings at baseline and at the first follow-up colonoscopy; assessment of need for additional follow-up colonoscopy.

Control

Colorectal cancer rates in the general population.

Outcome

New diagnosis of colorectal cancer after the first follow-up colonoscopy; and after a second follow-up colonoscopy when performed.

Follow-up Period

Median 8.0 years after the first follow-up colonoscopy (registry follow-up through 2017).

Results

Patient group (polyp risk) Time period Relative colorectal cancer incidence vs general population
Low risk at baseline and first follow-up After first follow-up (until second follow-up or end) 0.48 (95% confidence interval 0.34 to 0.67)
High risk at baseline and first follow-up After first follow-up (until second follow-up or end) 2.84 (95% confidence interval 1.30 to 5.39)
Low risk at baseline and first follow-up After second follow-up (when performed) 0.56 (95% confidence interval 0.36 to 0.82)
Analysis approach: observational time-to-event; not randomized (no intention-to-treat/per-protocol).
Non-inferiority trial: no.
Minimally important difference: not established for this outcome.
Was the control current treatment? Comparison was to general-population rates, not an active treatment.

Limitations

Retrospective data with missing quality details; possible selection bias; reasons for repeat colonoscopies not always verifiable; very small “low-risk then high-risk” subgroup limited conclusions.

Funding

National Institute for Health Research; Cancer Research UK; funders had no role.

Clinical Application

After polyp removal, consider stopping ongoing follow-up if the first follow-up colonoscopy shows low-risk findings; prioritize a second follow-up when high-risk findings persist.