Cutaneous Toxicities of Small Molecules in Targeted Cancer Therapy Part I - Mechanisms of Toxicity

Advances in the understanding of cancer biology have led to a shift toward more precise, targeted anticancer therapies. Traditional chemotherapy acts as an intracellular poison to disrupt cell division or induce DNA damage resulting in cytotoxicity¹. However, the effects of traditional chemotherapy are not relegated to neoplastic tissue, resulting in significant off-target cytotoxicity². Targeted therapies were developed to provide a more specific approach to cancer treatment, focused on inhibiting the pathways involved in carcinogenesis and tumor growth. Small molecule inhibitors (SMIs) and antibody-based therapies are the two main pillars of this approach³. This review focuses on SMIs given their broad applicability across tumor types, rapidly expanding number of agents, and unique side effect profiles^4,5. Part I of this continuing medical education article reviews mechanisms of toxicity of dermatologic adverse events associated with SMIs.