Characteristics, incidence, and risk factors of immune checkpoint inhibitor-related pneumonitis in patients with non-small cell lung cancer.

OBJECTIVES

Immune checkpoint inhibitors (ICIs) can cause pneumonitis in lung cancer patients. We aimed to identify the clinical and radiologic characteristics, incidence, and risk factors of ICI-related pneumonitis in patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Medical records and chest computed tomography scans of NSCLC patients treated with an ICI over a 5-year period at a tertiary hospital were retrospectively analyzed. Clinical characteristics were compared between patients with and without ICI-related pneumonitis to identify risk factors.

RESULTS

Data from 167 eligible patients were analyzed. The incidences of all-grade and grade 3-4 pneumonitis were 13.2% and 4.2%, respectively. The presence of preexisting interstitial lung disease [odd ratio (OR), 6.03; 95% confidence interval (CI), 1.19-30.45; P = 0.030] was associated with a higher incidence of ICI-related pneumonitis. The presence of extrathoracic metastasis [OR, 0.34; 95% CI, 0.13-0.92; P = 0.034] was associated with a lower incidence of ICI-related pneumonitis. The dominant radiologic pattern (72.7%) of ICI-related pneumonitis was organizing pneumonia. Half of the patients with pneumonitis completely recovered or improved; however, the mortality rate was 18.2%.

CONCLUSION

ICIs should be used with caution when treating lung cancer patients who have underlying chronic lung disease, especially interstitial lung disease.