Abstract Rationale Lung cancer remains the leading cause of cancer mortality. Immune checkpoint inhibitors (ICIs) have improved outcomes; however, ICI-pneumonitis impacts patient outcomes and threatens treatment continuity. Characterizing the baseline demographic and pulmonary function profile of affected patients is essential for counseling, surveillance, and future risk model development. This analysis summarizes the demographics arm of our pneumonitis investigation. Methods We analyzed a registry of lung cancer patients aged ≤85 years (range: 41-85) at the University of Connecticut Neag Comprehensive Cancer Center who completed pulmonary function testing within three years before starting PD-1 or PD-L1 inhibitor therapy (atezolizumab, durvalumab, nivolumab, or pembrolizumab). Pneumonitis was adjudicated per American College of Chest Physicians criteria incorporating symptoms, imaging, temporal relationship to ICI exposure, improvement after drug cessation, and exclusion of competing diagnoses. Demographics, smoking history, thoracic radiation, oncology stage, insurance status, occupation, and the lung function score (LFS = FEV1% predicted grade + DLCO grade; higher scores indicate greater impairment) were collected for analysis. We generated descriptive summaries comparing patients with and without subsequent pneumonitis, reporting group-specific counts and percentages. Results Of 153 eligible patients, 41 (26.8%) developed ICI-pneumonitis. Patients with ICI-pneumonitis were marginally older (71.1 ± 6.7 vs 70.8 ± 8.4 years, p=0.92) and remained evenly split by sex (Female: 48.8% vs 42.9%). Both cohorts were predominantly White/non-Hispanic (89.3% for controls vs 90.2%). Prior thoracic radiation was more common in ICI-pneumonitis (82.9% vs 70.5%, p=0.12), and Medicare coverage predominated (70.7% vs 68.8%), followed by private insurance (17.1% vs 20.5%) and Medicaid (12.2% vs 9.8%). Smoking histories were similar—former smokers comprised 73.2% of cases and 75.9% of controls—but never-smokers showed increased signal among cases (12.2% vs 6.2%, p=0.31). Baseline lung function metrics differed: pneumonitis cases had higher LFS (mean 6.0, median 7) than controls (mean 5.2, median 5, p=0.034), with lower mean FEV1% (68.1% vs 74.0%, p=0.11) and DLCO% (56.0% vs 64.1%, p=0.02. Mean pack-year exposure remained comparable (39.2 vs 43.8, p=0.32). Corticosteroid therapy was documented for 87.5% of pneumonitis cases. Conclusions In this single-center cohort, ICI-pneumonitis affected roughly one quarter of treated lung cancer patients and was associated with older age, more frequent prior radiation exposure, and higher pre-treatment lung function scores. Racial composition and smoking history resembled the broader cohort, though pneumonitis cases included more Medicare beneficiaries and never-smokers. These demographic signals will guide targeted surveillance and inform future predictive models that integrate pulmonary function and treatment history to mitigate pneumonitis risk. This abstract is funded by: None
Krishna et al. (Fri,) studied this question.