Management of the adverse effects of targeted therapy for cancer

Background: Advances in genomics and molecular biology over the past 20 years have resulted in numerous approved molecular targeted cancer therapies. The two main approaches for targeted cancer therapy are monoclonal antibodies and small molecules. Targeted therapy is expected to exert few side effects, but a new class of toxicities has been reported. Thus, the classical chemotherapy-induced toxicities of alopecia, myelosuppression, mucositis, nausea, and vomiting have been replaced in patients receiving targeted therapies by dermatologic, cardiovascular, gastrointestinal, endocrine, ocular, and pulmonary toxicities, and infusion reactions.Current Concepts: Targeted therapy toxicities vary, but common side effects include skin rash, diarrhea, and stomatitis. Most of these side effects are mild and can be prevented and treated. Rare and dangerous side effects, including pneumonitis, cardiotoxicities, and infusion reactions, can also be induced by targeted therapies. In most cases, toxicities are low grade (grade ≤2) and can be treated effectively, but in some cases, they can be fatal without appropriate intervention. Symptoms can be nonspecific, rendering identification of early symptoms challenging. Physicians should thus be aware of these side effects and manage toxicities appropriately.Discussion and Conclusion: The side effects of targeted therapy exert a critical impact on survival and quality of life. Most patients receiving targeted therapy need help to prevent and relieve toxicities. Management of the toxicities of targeted therapy involves patient monitoring, adjusting therapeutic dose or frequency, and providing supportive care. Serious side effects require early detection and prompt intervention, including discontinuation of targeted therapy and the use of corticosteroids.