Association Between Preexisting ILAs, Smoking History and ICI-Related Pneumonitis

An association between the presence of preexisting interstitial lung abnormalities (ILAs) and the development of immune checkpoint inhibitor (ICI)-related pneumonitis was not statistically significant, whereas smoking history was a significant predictor. These study findings were reported in the journal The Oncologist.

The study included patients with non-small cell lung cancer, malignant melanoma, renal cell carcinoma, or gastric cancer who received nivolumab, pembrolizumab, or atezolizumab. Included patients underwent ICI therapy between September 2014 and January 2019 at a hospital in Japan.

The study investigators evaluated patient baseline characteristics, in addition to clinical outcomes, high-resolution computed tomography–based findings from prior ICI therapy, and immune-related adverse events. A goal of the study was to determine if a preexisting ILA or other characteristics could be associated with development of pneumonitis associated with ICI therapy.

There were 209 patients included in the analysis, and they had a median age of 68 years. A smoking history was identified in 59.8% of patients. Patients overall had a median follow-up time of 11.0 months (range, 0.04 to 53.0).

In the overall study population, 23 (11.0%) patients developed ICI-related pneumonitis. Among the patients with ICI-related pneumonitis, 3 experienced grade 5 events, and 16 (69.6%) experienced grade 2 or 3 events.

Some factors that appeared to associate with developing ICI-related pneumonitis in this population included smoking history (P =.005) and type of ICI (P =.044). However, across all categories of preexisting ILA combined the association with ICI-related pneumonitis not significant (P =.428). There also was no statistically significant association between ICI-related pneumonitis and various features of ILAs, such as ground-glass attenuation, reticular shadow, and others.

The investigators performed a multivariate analysis to identify any significant predictors of ICI-related pneumonitis. The sole factor identified as an independent predictor of ICI-related pneumonitis was smoking history (P =.028). Preexisting ILAs and type of ICI therapy used were not significant predictors of ICI-related pneumonitis.

“While our results may support the use of ICI in patients with ILA, its safety is not yet guaranteed, and further research is warranted for understanding the risk factors of ICI-related pneumonitis,” the study investigators wrote in their report.

Reference

Horiuchi K, Ikemura S, Sato T, et al. Pre-existing interstitial lung abnormalities and immune checkpoint inhibitor-related pneumonitis in solid tumors: a retrospective analysis. Oncologist. Published online August 17, 2023. doi:10.1093/oncolo/oyad187