American Board of Internal Medicine (ABIM) Certification Practice Exam

For patients with Lynch syndrome, what is the recommended interval for colonoscopy screening?

1. Every 1 to 2 years

2. Every 3 to 4 years

3. Every 5 years

4. Only as symptoms arise

The correct answer is: Every 1 to 2 years

For patients with Lynch syndrome, the recommended interval for colonoscopy screening is every 1 to 2 years. Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), increases an individual's risk for colorectal cancer and other malignancies due to defective DNA mismatch repair mechanisms. Given this heightened risk, regular surveillance is crucial for early detection and intervention. By recommending screenings every 1 to 2 years, healthcare providers aim to identify any precancerous lesions or early-stage cancers before they can progress. This frequency is supported by guidelines from professional organizations involved in managing hereditary cancer risks, which emphasize that increased surveillance can significantly improve outcomes by detecting cancers at a more treatable stage. In contrast, longer intervals, such as every 3 to 4 years or every 5 years, may not provide adequate monitoring for individuals with Lynch syndrome, given their substantial risk of developing colorectal cancer at a younger age. Similarly, only screening when symptoms arise is insufficient for this group, as symptoms may not present until the disease is advanced. Thus, adhering to the guideline of every 1 to 2 years ensures that patients with Lynch syndrome receive the necessary preventative care to mitigate their cancer risk.