Introduction: Immune checkpoint inhibitors (ICI) are increasingly being administered to cancer patients, including those with brain metastases (BMs). However, little is known about the interaction between ICI and steroids such as dexamethasone. The aim of this study was to perform a systematic literature review and meta-analysis on the association between steroid use and overall survival (OS) in BM patients receiving ICI.
Methods: A systematic literature search was performed in PubMed, Embase, Web of Science, Cochrane, Academic Search Premier, and PsycINFO. Pooled effect estimates were calculated using random-effects models; analysis was performed across all included studies and stratified by tumor type.
Results: After screening 978 abstracts, thirteen studies were included for systematic review. Ten studies reported sufficient data for meta-analysis, comprising 838 BM patients of which 335 (40%) had received steroids. In the steroid group, median OS ranged from 2.9 months to 10.2 months across studies. In the non-steroid group, median OS ranged from 4.9 to 25.1 months. Pooling results demonstrated significantly worse survival in the steroid group (HR 1.97; 95% CI 1.65-2.36); no significant heterogeneity (I2 = 0%) or publication bias (Egger’s p = 0.29) was identified. Stratified analysis showed a consistent effect across melanoma (HR 1.71, 95% CI 1.34-2.18) and non-small cell lung cancer (HR 2.26, 95% CI 1.49-3.43) subgroups.
Conclusion: Administration of steroids is associated with a significantly worse OS in BM patients receiving ICI. Further investigation on dose, timing and duration of steroids in this population is needed to elucidate the cause of this association and optimize outcomes in BM patients receiving ICI.