Background: Immune checkpoint inhibitors (ICIs) are a first-line and perioperative treatment for lung cancer. Pneumonitis is a potentially life-threatening complication of ICI treatment in 2% to 5% of patients; however, risk factors for developing ICI pneumonitis (ICI-p) remain undefined. Methods: We conducted a retrospective cohort study of consecutive patients with lung cancer who received at least one dose of ICI from 2015 through 2020 at The Ohio State University. Pneumonitis cases were documented by the treating oncologist and retrospectively evaluated for agreement between an oncologist and a pulmonologist. Patient demographic and clinical characteristics were recorded and summarized between those with and without pneumonitis for the overall cohort. Univariate and multivariable survival analyses using the Fine-Gray competing risk model were used to examine the associations. Results: A total of 471 patients with lung cancer were included, of which 402 had non–small cell lung cancer and 69 had small cell lung cancer; 39 (8%) patients in the overall cohort developed ICI-p. Preexisting interstitial abnormalities and prior chest radiation were both significantly associated with ICI-p on univariate analysis (hazard ratio [HR], 8.91; 95% CI, 4.69–16.92; P<.001; and HR, 2.81; 95% CI, 1.50–5.28; P=.001). On multivariable analyses, interstitial abnormalities remained a strong independent risk factor for ICI-p when controlling for chest radiation and type of immunotherapy (HR, 9.77; 95% CI, 5.17–18.46; P<.001). Among patients with ICI-p (n=39), those with severe (grade 3–5) pneumonitis had worse overall survival compared with those with mild (grade 1 or 2) pneumonitis (P=.001). Abnormal pulmonary function test results at both 12 and 18 months prior to ICI initiation were not significantly associated with ICI-p. Conclusions: Preexisting interstitial abnormalities on chest CT and prior chest radiation are independent risk factors that are strongly associated with ICI-p in patients with lung cancer. These findings highlight a potential need for closer observation for ICI-p among patients with these risk factors.
Submitted May 21, 2023; final revision received July 17, 2023; accepted for publication July 18, 2023.
Author contributions: Study design: Wong, Owen, Ho. Data acquisition: Wong, Riley, Zimmer, Viveiros, Li, Lopez, Kendra, Carbone, He, Alahmadi, Kaufman, Memmott, Shields, Brownstein, Haglund, Welliver, Otterson, Presley, Owen, Ho. Database management: Kendra, Carbone, He, Alahmadi, Kaufman, Memmott, Shields, Brownstein, Haglund, Welliver, Otterson, Presley, Owen. Statistical analysis: Zhao, Wei. Imaging review: Wang, Esguerra, Ho. Manuscript preparation: Wong, Riley, Zhao, Wei, Owen, Ho.
Disclosures: Dr. Kendra has disclosed receiving grant/research support from Bristol Myers Squibb, Checkmate Pharmaceuticals, GSK, Immunocore, Medpace, Merck, Novartis, and Varian Medical Systems. Dr. Brownstein has disclosed receiving honoraria from AstraZeneca and DAVA Oncology; and receiving grant/research support from Varian Medical Systems. Dr. Otterson has disclosed serving as a data safety monitoring board for BeiGene and Novocure; and receiving grant/research support from Bristol Meyers Squibb, Genentech, Merck, Dizal, AbbVie, Apollomics, and Nuvalent. Dr. Presley has disclosed receiving grant/research support from Jazz Pharmaceuticals. Dr. Owen has disclosed receiving grant/research from Bristol Myers Squibb, Genentech, Pfizer, Palobiofarma, AbbVie, Merck, Elevation Oncology, and Onc.AI; and serving as a principal investigator for Genentech, Palobiofarma, Bristol Myers Squibb, Merck, Pfizer, and Onc.AI. The remaining authors have disclosed that they have not received any financial consideration from any person or organization to support the preparation, analysis, results, or discussion of this article.