A retrospective study on immune-related pneumonitis in patients with non-small-cell lung cancer undergoing treatment with PD-1/PD-L1 inhibitors

Abstract

ABSTRACT Background Lung cancer patients undergoing treatment with immune checkpoint inhibitors (ICIs) are at risk of developing immune-related (ir-)pneumonitis. Since lung cancer patients have competing reasons for respiratory symptoms, this poses a diagnostic challenge. This study aimed to explore diagnosis and management of ir-pneumonitis in this patient group. Materials and Methods Retrospective database retrieved analysis of patients with non-small cell lung cancer undergoing treatment with PD-1/PD-L1 inhibitors at Department of Oncology, Copenhagen University Hospital, Herlev. Patients being suspected of ir-pneumonitis during the period 01.07.2016 – 15.06-2020 were selected. Results Out of 377 eligible patients, 83 were suspected of ir-pneumonitis. A thoracic computed tomography (CT) was made in 93% of the patients, and 34% had a sputum sample made. A specialist in pulmonology was consulted in seven patient cases. Ir-pneumonitis was radiologically confirmed in 34 patients, however, in 12 patients symptoms could not be confined to ir-pneumonitis and only 22 patients were included in the analysis of the course of treatment. Solely corticosteroids were used as systemic treatment, and the median duration of treatment was 16 weeks (4-34). In seven patients pneumonitis was consistent with recall radiation pneumonitis (RRP). Conclusion Suspected ir-pneumonitis was frequent in this group of patients. The cohort was characterized by high heterogeneity and lack of unequivocal diagnostic conclusions. Treatment of ir-pneumonitis was longer than recommended and involvement of pulmonologist was very infrequent. The result of this study reflects the difficulties in a daily clinical setting to diagnose and manage patients with lung cancer presenting with pulmonary symptoms.