American Board of Internal Medicine (ABIM) Certification Practice Exam

What class of agents includes bevacizumab and sunitinib in the treatment of metastatic renal cell carcinoma?

1. Tyrosine kinase inhibitors

2. Vascular endothelial growth factor (VEGF) inhibitors

3. Mammalian target of rapamycin (mTOR) inhibitors

4. Monoclonal antibodies

The correct answer is: Vascular endothelial growth factor (VEGF) inhibitors

Bevacizumab and sunitinib are both important agents used in the treatment of metastatic renal cell carcinoma, and their classification is crucial for understanding their mechanism of action. Bevacizumab is a monoclonal antibody that specifically targets vascular endothelial growth factor (VEGF), a key protein that promotes the growth of blood vessels, a process known as angiogenesis. Inhibiting VEGF prevents the formation of new blood vessels that tumors require for growth and metastasis, making bevacizumab effective in slowing the progression of cancer. Sunitinib, while primarily a tyrosine kinase inhibitor, also exerts its effects by inhibiting the pathways associated with VEGF signaling, thereby disrupting the angiogenic process. This dual mechanism of action reinforces the importance of VEGF in tumor pathophysiology. The classification of these agents under VEGF inhibitors reflects their shared function in targeting the vascular supply to tumors, which is critical in managing metastatic renal cell carcinoma. This focus on angiogenesis as a therapeutic target has transformed the landscape of cancer treatment, particularly for renal cell carcinoma, where angiogenesis plays a pivotal role in disease advancement.