Analysis of baseline interstitial lung abnormality on the risk of checkpoint inhibitor-related pneumonitis and survival in advanced non-small cell lung cancer patients treated with first-line PD-1/PD-L1 inhibitors.

Background: Chest computed tomography (CT) can be used to identify interstitial lung abnormality (ILA), which is known to lead to an increased risk of post-operative complications, and is related to a worse prognosis in early-stage lung cancer. However, research on the role of ILA in advanced non-small cell lung cancer (NSCLC) patients receiving immunotherapy is limited. This study sought to investigate the effect of pre-existing ILA and pulmonary function test (PFT) results on the occurrence of checkpoint inhibitor-related pneumonitis (CIP) and survival in advanced NSCLC patients after programmed cell death protein-1 (PD-1) or programmed cell death-ligand 1 (PD-L1) inhibitor therapy. Methods: We retrospectively divided the patients with advanced NSCLC into two groups: the with ILA group, and the without ILA group. We also divided the patients into two groups based on whether they developed CIP during treatment. After first-line immunotherapy, we followed up with all patients and recorded their progression-free survival (PFS) and overall survival (OS). Two respiratory specialists recorded the cases of CIP and the existence of ILA on chest CT, and assessed the consistency of ILA. A logistic regression analysis was performed to explore the independent risk factors for CIP, and a Cox regression analysis was performed to investigate the factors influencing PFS and OS. Results: Of the 269 patients with advanced NSCLC enrolled in the study, 93 (34.57%) had ILA, and 176 (65.43%) did not have ILA. Additionally, 39 (14.50%) of the patients developed CIP. The univariate analysis showed that pre-existing ILA [odds ratio (OR): 3.733; 95% confidence interval (CI): 1.846-7.549; P<0.001], body mass index (BMI) (≥24.12 kg/m Conclusions: Pre-existing ILA is an independent risk factor that is strongly associated with CIP, and significantly correlated with worse PFS and OS in advanced NSCLC patients after first-line immunotherapy.