American Board of Internal Medicine (ABIM) Certification Practice Exam

Which tumors are typically amenable to breast-conserving therapy?

1. Tumors larger than 5 cm

2. Tumors involving multiple quadrants

3. Tumors 5 cm or less with clear margins

4. Tumors with distant metastasis

The correct answer is: Tumors 5 cm or less with clear margins

Breast-conserving therapy, often referred to as lumpectomy followed by radiation, is primarily indicated for tumors that can be adequately removed while preserving a sufficient amount of breast tissue and leaving clear margins to reduce the risk of local recurrence. Tumors measuring 5 cm or less with clear margins are typically amenable to this form of treatment because they can be adequately excised without removing an excessive amount of breast tissue. Clear margins indicate that the excised tumor was completely surrounded by normal tissue, which is crucial in decreasing the likelihood of remaining cancerous cells that could lead to recurrence. In contrast, tumors larger than 5 cm often require more extensive surgical measures, such as mastectomy, to ensure all cancerous tissue is removed safely. Tumors involving multiple quadrants can complicate the surgical approach, making it challenging to achieve clear margins while preserving the breast, thus making them less suitable for conservation approaches. Lastly, tumors with distant metastasis indicate advanced disease, where the focus is typically on systemic therapy rather than local control through surgical means. Therefore, tumors that are 5 cm or less with clear margins represent an ideal scenario for breast-conserving therapy.