Association of pre-existing lung interstitial changes with immune-related pneumonitis in patients with non-small lung cancer receiving immunotherapy.

Background And Aim: Many pieces of literature have evaluated the predictive value of pre-existing lung interstitial changes for immunotherapy-related pneumonia in patients with non-small cell lung cancer (NSCLC), but the results of studies are still controversial. The purpose of this article is to explore whether pre-existing lung interstitial changes can predict the occurrence of immunotherapy-related pneumonia.

Methods: PubMed, Web of Science, and Embase were used to search for relevant documents. Two investigators respectively carried out literature screening, quality evaluation, and data extraction strictly according to the inclusion criteria. Odds ratios (ORs) and the corresponding 95% CIs were applied to assess the predictive value of interstitial lung disease (ILD), interstitial lung abnormalities (ILA), and radiation pneumonitis (RP). Stata 12.0 software was used for the statistical analysis of data.

Results: Seventeen studies involving 2758 patients were included in the final analysis. NSCLC patients with pulmonary interstitial changes were more likely to develop immune-related pneumonia after immunotherapy (OR = 3.68, 95% CI: 2.49-5.44). Subgroup analysis revealed that ILD (OR = 3.59, 95% CI: 2.22-5.82), RP (OR = 3.63, 95% CI: 1.80-7.30), and ILA (OR = 6.64, 95% CI: 1.78-24.8) were all predictors of immune-related pneumonia. As the preliminary screening of other risk factors, gender, neutrophilic lymphocyte ratio (NLR), actual eosinophil count (AEC), and drug type may have potential predictive value for immunotherapy-related pneumonia. There was no significant statistical heterogeneity and publication bias in our study. Further research is needed to update and validate our results.

Conclusion: Pulmonary interstitial changes can be considered as a predictive factor of immune-related pneumonia after immunotherapy in NSCLC patients.