Association of Preexisting Interstitial Lung Abnormalities With Immune Checkpoint Inhibitor-Induced Interstitial Lung Disease Among Patients With Nonlung Cancers

This cohort study evaluates whether interstitial lung abnormalities are associated with immune checkpoint inhibitor-induced interstitial lung disease in patients with nonlung cancers. Importance Immune checkpoint inhibitor-induced interstitial lung disease (ICI-ILD) is clinically serious and life-threatening. Preexisting interstitial lung abnormalities have been shown to be risk factors for ICI-ILD in patients with lung cancer. Objective To evaluate whether interstitial lung abnormalities are associated with ICI-ILD in patients with nonlung cancers. Design, Setting, and Participants This cohort study was conducted between December 2015 and May 2019 at Hiroshima University Hospital. A total of 199 consecutive patients with head and neck cancer, malignant melanoma, oral cavity cancer, urological cancer, and gastrointestinal cancer who received anti-programmed cell death 1 (PD-1) antibody monotherapy were included. Data analysis was conducted from December 2015 to May 2019. Main Outcomes and Measures The associations between potential risk factors and the development of ICI-ILD were examined. Information on patient characteristics before antibody administration, including chest computed tomography findings, was obtained. The diagnosis of ICI-ILD was defined as abnormal computed tomography shadows occurring during treatment with anti-PD-1 antibodies. Results A total of 199 patients were enrolled in the study. The median (range) age was 66 (20-93) years, and most patients (133 [66.8%]) were men. Nineteen patients (9.5%) developed ICI-ILD. There was no significant difference in the baseline characteristics between patients with and without ICI-ILD. The logistic regression analyses revealed that interstitial lung abnormalities were associated with increased risk of ICI-ILD (odds ratio, 6.29; 95% CI, 2.34-16.92; P < .001), and ground glass attenuation in interstitial lung abnormalities was an independently associated risk factor (odds ratio, 4.05; 95% CI, 1.29-12.71; P = .01). Conclusions and Relevance In this cohort study, preexisting interstitial lung abnormalities, including ground glass attenuation, were risk factors associated with ICI-ILD in patients with nonlung cancers. This observation is consistent with previously reported findings in patients with lung cancer. Therefore, we should pay more attention to the development of ICI-ILD in patients with interstitial lung abnormalities, regardless of cancer type. Question Are interstitial lung abnormalities, which are minor interstitial shadows on lung computed tomography, associated with immune checkpoint inhibitor induced-interstitial lung disease in patients with nonlung cancers? Findings In this cohort study of 199 patients with advanced nonlung cancers treated with anti-programmed cell death 1 antibody monotherapy, patients with preexisting interstitial lung abnormalities had significantly increased risk of immune checkpoint inhibitor induced-interstitial lung disease. Meaning These findings suggest that greater attention should be accorded to the development of immune checkpoint inhibitor induced-interstitial lung disease in patients with nonlung cancers and interstitial lung abnormalities.