Toxicities related to medications constitute a major category of iatrogenic illness. All agents used for cancer treatment have the potential to cause toxicity. As with every medical intervention, the risks of treatment may be acceptable if they are outweighed by the potential benefit of longer survival or cure of disease. It is essential that the patient be engaged in a discussion of this balance before embarking on treatment.
Over the past decade, the landscape of oncologic therapeutics has witnessed enormous advances, with scientific discovery driving substantial and innovative change. The emergence of molecularly targeted treatments and immunotherapy has fundamentally changed both front-line and secondary approaches for a multitude of cancers, enhancing precision and personalization of therapy. The success of new treatments inevitably will be tempered by a new array of associated pulmonary complications, the extent and severity of which may not be completely elucidated in clinical trials. We are very much still in the learning curve of recognizing and addressing related toxicities of novel therapeutics. Moreover, cancer treatments often carry the additional complexity of combination approaches with other drugs or radiation, concomitant hematopoietic support, or bone marrow or stem cell transplantation. Further, as advances in therapeutics result in improved long-term survival, cancer is becoming a chronic disease for a growing number of patients. The potential for delayed complications adds additional challenge to the evaluation of pulmonary complaints in cancer survivors.
As knowledge of biologic mechanisms fundamental to neoplasia burgeons, the horizon for treatment approaches will continue to expand, and inevitably so will the spectrum of associated pulmonary complications. Consequently, the pulmonologist must maintain a sharp awareness of the potential for treatment-related toxicities in both short- and long-term oncologic settings. This chapter reviews the evaluation of patients with suspected therapy-induced pulmonary toxicity and the potential toxicities associated with specific classes of systemic treatment.
APPROACH TO THE PATIENT WITH SUSPECTED PULMONARY TOXICITY RELATED TO SYSTEMIC TREATMENT FOR CANCER
The evaluation of patients with cancer who develop pulmonary complications while receiving treatment is often challenging, as the diagnosis of drug-induced pulmonary toxicity is typically one of exclusion. The possibility of adverse effects of therapy must be considered within the complex medical context inherent to an individual patient undergoing physically challenging and often immunosuppressing treatment. Patients most often present with nonspecific constitutional or respiratory complaints. In many cases, symptoms and physical signs may be minimal or even absent. In these situations, the only evidence of an ongoing pulmonary process may be an abnormal chest radiograph or computed tomography (CT) scan. Even when clinical symptoms and imaging abnormalities are present and severe, they are usually nonspecific. Reasonable certainty that the patient’s clinical complaints and radiographic ...