Chapter 63: Pulmonary Complications of Cancer Therapy

KEY CONCEPTS

• Lung injury caused by cancer therapy results in stereotypical histopathologic disease patterns and syndromes. These lung injury patterns may be triggered by conventional chemotherapy, molecularly targeted agents, and immune modulators. The diagnosis is suggested by a temporal association with the drug and the development of compatible findings, coupled with exclusion of competing diagnoses. Recommendations to guide management of drug-induced lung injury are available, but evidence-based guidelines are limited.

• Albeit rare when compared to other forms of immune-related adverse events (IrAEs), lung involvement, specifically pneumonitis, is recognized as potentially one of the most lethal forms of IrAEs. The Common Terminology Criteria for Adverse Events stratifies pneumonitis based on the presence and severity of clinical symptoms, and treatment recommendations are based on these categories.

• Various cancer-related conditions may cause pulmonary hypertension (PH), and each condition is represented in the five categories of the revised 2019 World Health Organization classification scheme for PH. Each PH category is managed in a specific manner, and treatment of the underlying malignancy may lead to resolution or improvement of PH in some instances.

• Symptoms of malignant central airway obstruction (CAO) may mimic other more common diseases and may not develop until greater than 50% narrowing of the main airways has occurred. A high degree of suspicion must be maintained in patients at increased risk for CAO presenting with symptoms of cough, hemoptysis, stridor, focal wheezing, dyspnea, atelectasis, or recurrent or persistent postobstructive pneumonia.

• Pleural effusion is common in patients with cancer and can arise from malignant involvement of the pleura or secondary to a variety other causes such as bronchial obstruction, infiltration of mediastinal lymph nodes, superior vena cava syndrome, trapped lung, pulmonary embolism, or atelectasis. Chest radiography, chest computed tomography (CT), and thoracic ultrasonography are the imaging modalities most commonly used in evaluating potential causes and contributors to pleural effusion.

• Sleep disturbances are quite common in patients with cancer and can include insomnia, poor sleep efficiency, early awakening, excessive daytime sleepiness, and restless legs. These sleep disorders may occur during all phases of cancer care and can persist for months to years after completion of cancer therapy. Cognitive behavioral therapy is the treatment of choice for patients with many of these sleep disturbances.