Clinical and radiological features of immune checkpoint inhibitor-related pneumonitis in lung cancer and non-lung cancers

• DOI: 10.1259/bjr.20200409
• Publication Date: 2020-08-12T18:44:20Z
• Authors: Tomomi W Nobashi; Yuko Nishimoto; Yujiro Kawata; Hidetaka Yutani; Masaki Nakamura; Yuichi Tsuji; Atsushi Yoshida; Akihiko Sugimoto; Takayuki Yamamoto; Israt S Alam; Satoshi Noma
• Keywords: Aged, 80 and over; Male; Lung Neoplasms; Polysaccharides, Bacterial; Programmed Cell Death 1 Receptor; Pneumonia; Middle Aged; Antibodies, Monoclonal, Humanized; Bronchiectasis; 3. Good health; Radiation Pneumonitis; 03 medical and health sciences; Antineoplastic Agents, Immunological; Nivolumab; 0302 clinical medicine; Cryptogenic Organizing Pneumonia; Neoplasms; Humans; CTLA-4 Antigen; Female; Tomography, X-Ray Computed; Aged; Retrospective Studies

Objective:To investigate the clinical and radiological features of immune checkpoint inhibitor-related pneumonitis (ICI-P), a rare but serious pulmonary complication of cancer immunotherapy and to evaluate key differences between lung cancer (LC) and non-LC patients.Methods:247 patients (LC, n = 151) treated with ICI for malignancies were retrospectively screened in a single institute. The number of patients, history of other immune-related adverse events (irAE), the onset, serum KL-6 levels, and chest CT features (types of pneumonitis, symmetry, laterality, location) were recorded for the ICI-P population and compared for LC and non-LC groups.Results:ICI-P was identified in 26 patients in total (LC, n = 19; non-LC, n = 7). The incidence of other irAE was significantly higher in ICI-P group (63%) compared with patients without ICI-P (34%) (p = 0.0056). An earlier onset of ICI-P was recorded in LC (78 days) compared to non-LC patients (186 days) (p = 0.0034). Serum KL-6 was significantly elevated only in the non-LC group when ICI-P was noticed (p = 0.029). Major CT findings of ICI-P, irrespective of primary disease, were organizing pneumonia pattern and ground glass opacities. LC patients commonly exhibited consolidation and traction bronchiectasis and were prone to asymmetrical shadows (p < 0.001). Non-LC patients were more likely to exhibit symmetrical infiltrations. A small fraction of both groups experienced relapse or moving patterns of ICI-P.Conclusion:ICI-P patients more often experienced other irAE prior to the development of ICI-P. The characteristics of ICI-P can differ in terms of the onset, KL-6 reliability, and chest CT findings between LC and non-LC patients.Advances in knowledge:In ICI-P patients, a history of other irAE can be more frequently observed. Differences in disease onset and radiological patterns between LC and non-LC patients might be helpful to make a diagnosis of ICI-P; however, longitudinal observation of chest CT scans is advised to observe the pneumonitis activity irrespective of cancer types.