American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the treatment approach for high-grade poorly differentiated neuroendocrine tumors of unknown primary site?

1. Surgery followed by radiation

2. Systemic platinum-based chemotherapy

3. Only symptomatic treatment

4. Targeted therapy

The correct answer is: Systemic platinum-based chemotherapy

The treatment approach for high-grade poorly differentiated neuroendocrine tumors (NETs) of unknown primary site typically involves systemic platinum-based chemotherapy. This modality is particularly favored because these tumors often exhibit aggressive behavior and a high potential for metastasis, making the need for a systemic treatment strategy paramount. High-grade poorly differentiated NETs are generally categorized by their rapid proliferation and low differentiation, which correlates with poorer clinical outcomes. After careful evaluation and staging, systemic chemotherapy offers a broader reach to target cancer cells throughout the body, which is crucial in cases where the primary site is unidentified. Cisplatin or carboplatin paired with etoposide is a common regimen used in this context. This approach aims to manage the disease aggressively and improve survival rates. In contrast, surgical options might be considered for localized disease, but in the case of unknown primaries, the systemic nature of the disease typically precludes a surgical solution as the primary intervention. Targeted therapies and solely symptomatic treatment do not effectively address the aggressive nature of these high-grade tumors as primary treatment options, hence their lesser role in this scenario.