Pulmonary Complications of Lung Cancer Therapies

Advances in the understanding of biologic mechanisms and molecular drivers of malignant disease have led to a new era in the management of a variety of cancers. In lung cancer, radiation therapy is often combined with treatment regimens containing molecular targeted therapies, immunotherapies, and conventional cytotoxic chemotherapy as standard of care for patients with advanced-stage disease. Pneumonitis is an infrequent, but potentially fatal toxicity of lung cancer pharmacotherapy. Although risk factors and mechanisms of lung injury for each category of cancer pharmacotherapy are unique, a stereotyped spectrum of lung injury patterns has been linked to each treatment category. The potentially life-threatening clinical manifestations are notoriously unpredictable and often variable from one drug class to the next. Clinical signs and symptoms may regress with prompt diagnosis and drug cessation, which underscores the critical need for early recognition of the clinical and radiographic features of drug toxicity. Unlike pneumonitis associated with cancer pharmacotherapy, radiation-induced pneumonitis tends to be predictable, dose-dependent and follows a mild clinical course in most patients, although specific risk factors and radiation sensitizing agents may predispose patients to severe lung injury. Thus, knowledge of the clinical presentation and risk factors caused by cancer pharmacotherapies and thoracic radiation is critical in management of lung cancer patients undergoing antineoplastic therapies.