Brain metastases (BM) occur in 40% of lung cancer patients. The activity of immunotherapy in these patients, however, remains controversial, as the cornerstone treatment is radiotherapy (RT). Since RT is associated with adverse events that may impair quality of life, the possibility of substituting it by a single systemic approach is attractive. Therefore, we performed a systematic review and meta-analysis to evaluate the potential benefit of immune checkpoint inhibitors (ICIs) in non-small cell lung cancer (NSCLC) patients with untreated BM (unBM).
Studies that enrolled NSCLC patients treated with ICIs and specifically allowed for unBM were identified by searching the Embase, PubMed, Cochrane and other databases. The outcomes evaluated were intracerebral overall response rate (icORR) and intracerebral disease control rate (icDCR) for unBM, and grades 3/4 toxicity rate.
We included 12 studies, with a total of 566 individuals, in the final analysis. Anti-PD1 therapy appears to be active in the central nervous system, with an icORR of 16.4% (95% CI 9.8% – 24%; I = 33.17%) and an icDCR of 45% (95% CI 33.4% – 56.9%; I = 46.91%). In the meta-analysis for icORR (risk ratio [RR] 1.26, 95% CI: 0.57 – 2.79) and icDCR (RR 0.88, 95% CI: 0.55 – 1.43) we did not observe any difference between patients with BM who were treated with RT prior to ICI start and those who were treated with ICI only.
ICIs appear to be effective as a single treatment for active BM in selected patients with advanced NSCLC.

Copyright © 2021. Published by Elsevier Inc.

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