Transbronchial cryobiopsy, updated guidelines for chronic cough in children, PD-1 inhibition
Thoracic Oncology
Immune-mediated pneumonitis and PD-1 inhibition
Inhibitors of the programmed cell death 1 receptor (PD-1) have shown significant promise in the treatment of advanced stage malignancy. With the recent expansion of indications for use of these agents, the number of patients treated will continue to grow. Clinicians must be aware of their potential for serious adverse side effects, including dermatitis, colitis, and potentially life-threatening pneumonitis.
The development of pneumonitis secondary to PD-1 inhibitions is reported to occur in 2% to 5% of patients and can present at any time during therapy, with 1% of patients developing grade 3 or higher pneumonitis.1,2 The most common symptoms are dyspnea and cough, though one-third of patients are asymptomatic at presentation.2 Radiographic and pathologic features vary greatly and include organizing pneumonia, interstitial pneumonitis, hypersensitivity pneumonitis, or diffuse alveolar damage.3 While pneumonitis due to PD-1 inhibition is reportedly uncommon, the increasing number of patients expected to receive these medications will predictably result in increasing overall frequency of pneumonitis cases. In addition, the lack of large prospective randomized trials and reliance on radiographic rather than pathologic data in diagnosing immune-mediated pneumonitis gives one pause. Given the variability of presentation, lack of routine pathologic data, and increasing use of dual agents (eg, PD-1 and CTLA-4), chest physicians and medical oncologists should have a high index of suspicion yet practice equipoise in patients receiving immunotherapy who develop unexplained pulmonary symptoms or infiltrates. More research is needed to help improve the multidisciplinary diagnosis and treatment of this potentially serious complication.
David Maurice Chambers, MD
Fellow-in-Training Member
Jason Atticus Akulian, MD, MPH
Steering Committee Member
References
1. Nishino M, et al. Incidence of programmed cell death 1 inhibitor-related pneumonitis in patients with advanced cancer: a systematic review and meta-analysis. JAMA Oncology. 2016;2(12):1607.
2. Naidoo J, et al. Pneumonitis in patients treated with anti-programmed death-1/programmed death ligand 1 therapy. J Clin Oncol. 2017;35(7):709.
3. Nishino M, et al. PD-1 inhibitor-related pneumonitis in advanced cancer patients: radiographic patterns and clinical course. Clin Cancer Res. 2016;22(24):6051.
