American Board of Internal Medicine (ABIM) Certification Practice Exam

After colorectal cancer treatment, how often should patients undergo colonoscopy if initial results are normal?

1. Every year

2. Every 3 years

3. Every 5 years

4. Every 10 years

The correct answer is: Every 3 years

For patients who have undergone treatment for colorectal cancer and show normal findings on their initial post-treatment colonoscopy, the recommended schedule for subsequent surveillance colonoscopies is every 3 years. This recommendation is based on the increased risk of colorectal cancer recurrence within the first few years following treatment. The rationale is to monitor for any development of new polyps or cancers that may arise as a consequence of the previous malignancy. Studies have shown that the risk is heightened in the first several years post-treatment, justifying the more frequent surveillance during this critical period. After the initial 3 years of regular monitoring and assuming no significant findings during these assessments, the interval may be adjusted to every 5 years, depending on the ongoing assessment of risk factors and the patient’s clinical condition. This reflects a progression in surveillance intervals that corresponds to the patient's overall risk stratification over time. Regular monitoring helps to ensure any new developments are caught early, which is essential for improving outcomes in these patients.