Background:

Lung cancer is increasingly treated with immune-checkpoint inhibitors (ICI). Checkpoint inhibitor-associated pneumonitis (CIP) decreases the quality of life and survival of patients immediately and may limit subsequent treatment options for survivors.

Aims: 

The aim of this research was to analyze clinical factors and biomarkers associated with pneumonitis in lung cancer patients under ICI.

Methods: 

We analyzed data of 293 patients with lung cancer and ICI therapy. We distinguished between any pneumonitis and CIP. Using univariate logistic regression, we identified patient and clinical characteristics, and therapy significantly associated with pneumonitis. Significant factors were then included in a multivariate logistic regression analysis.

Results: 

We found 44 patients with any pneumonitis including 12 patients with CIP. Antibiotics (OR=2.05, p=0.31), radiotherapy (OR=3.37, p=0.001), low FEV1 (OR=1.48, p=0.038), low pO2 (OR=1.36, p=0.043) and neutrophil to lymphocyte ratio (OR=0.90, p=0.037) in the univariate analysis, antibiotics (OR=2.18, p=0.035) and radiotherapy (OR=3.25, p=0.002) in the multivariate analysis were significantly associated with any pneumonitis. Age (OR=0.93, p=0.007), pericardial effusion (OR=5.52, p=0.017) and serum eosinophils (OR=1.19, p=0.004) in the univariate analysis, age (OR=0.92, p=0.003) and pericardial effusion (OR=6.86, p=0.004) in the multivariate analysis were significantly associated with CIP.

Conclusion: 

Our results suggest differing clinical risk factors for CIP vs. other pneumonitis in ICI therapy. This highlights the need for further investigations of the pathophysiology of specific types of pneumonitis.