Immune checkpoint inhibitor-related interstitial lung disease in patients with advanced non-small cell lung cancer: systematic review of characteristics, incidence, risk factors, and management

BACKGROUND: Immune checkpoint inhibitors (ICIs) are widely used in cancers with or without other treatments. Immune-related adverse events (irAEs) have been reported as side effects of ICIs and involve various organs. Pneumonitis, which is also called ICI-related interstitial lung disease (ILD), is one of the life-threatening adverse events. In this report, we reviewed the safety of ICIs and risk factors for ICI-related ILD in non-small cell lung cancer (NSCLC) patients. METHODS: Databases (The National Center for Biotechnology Information, PubMed, Cochrane Library, Google Scholar, and Embase) were searched for the literature on pulmonary adverse events and immunotherapy following PRISMA guidelines. All studies published in English between January 2016 and June 2021 were included. RESULTS: One-hundred twenty-five articles were included at final. Pre-existing ILD as well as asthma and chronic obstructive lung disease (COPD) were associated with high risk for the development of ICI-related ILD, however, it did not affect the prognosis. The treatment of ICI-related ILD is different according to the severity grades, which includes discontinuation of ICI, corticosteroids, and for steroid-refractory ILD, other immunosuppressants. Rechallenging of ICI should be carefully considered in selected patients. DISCUSSION: Patients with pre-existing lung disease and poor lung function need more attention for the development of ICI-related ILD. It is necessary to be aware of clinical manifestation of ICI-related ILD with prompt management.