American Board of Internal Medicine (ABIM) Certification Practice Exam

For patients with Lynch syndrome, how many years earlier than the youngest diagnosis of colorectal cancer should they begin screening?

1. 1-2 years

2. 2-5 years

3. 5-10 years

4. No earlier screening recommended

The correct answer is: 2-5 years

For patients with Lynch syndrome, it is important to begin screening for colorectal cancer earlier than the youngest age of diagnosis in their family history. Lynch syndrome is a hereditary condition that significantly increases the risk of colorectal and other cancers due to mutations in DNA mismatch repair genes. Because of this heightened risk, patients are advised to start screening 2 to 5 years before the youngest diagnosis of colorectal cancer in a first-degree relative or according to specific guidelines related to their particular mutation. The rationale behind this timing is rooted in the understanding that individuals with Lynch syndrome develop colorectal cancer at an earlier age than the general population. Initiating screening earlier can help in detecting cancers at a more treatable stage as well as facilitating interventions that can mitigate cancer risk. Therefore, starting the screening process within the 2 to 5-year window provides a balance between proactive health management and avoiding unnecessary procedures or anxiety.