Immunotherapy with radiotherapy for brain metastases in non-small cell lung cancer patients:NEJ060

Background Immune checkpoint inhibitor (ICI)-based treatment has become standard treatment for advanced non-small cell lung cancer (NSCLC) patients. We aimed to reveal the survival benefit of upfront radiotherapy for brain metastases (BMs) in NSCLC patients who received ICI alone (ICI-alone) or with chemotherapy (ICI-chemo). Methods This study included consecutive NSCLC patients with BMs who received ICI-alone or ICI-chemo at 50 institutes between February 2017 and September 2021. The presence of BMs was confirmed by imaging before treatment. Treatment outcomes were compared between patients who did and did not receive upfront radiotherapy for BMs. Potential confounding factors were adjusted between the groups through inverse probability treatment weighting (IPTW) analysis and overlap weighting (OW) analysis with propensity scores. Results Patients were grouped as ICI-alone cohort, 224 patients (upfront-radiotherapy group, 135 patients; no-radiotherapy group, 89 patients); and ICI-chemo cohort, 367 patients (upfront-radiotherapy group, 212 patients; no-radiotherapy group, 155 patients). In the ICI-alone cohort, the overall survival (OS) of the upfront-radiotherapy group was significantly longer than that of the no-radiotherapy group (IPTW-adjusted hazards ratio [HR], 0.45 [95% CI, 0.29–0.72]; OW-adjusted HR, 0.52 [95% CI, 0.35–0.77]). In contrast, in the ICI-chemo cohort, the OS of the upfront-radiotherapy group was not significantly different from that of the no-radiotherapy group (IPTW -adjusted HR, 1.02 [95% CI, 0.70–1.48]; OW-adjusted HR, 0.93 [95% CI, 0.65–1.33]). Conclusions Upfront radiotherapy for BMs was associated with longer OS in NSCLC patients who received ICI-alone; however, it did not show survival benefits in the patients who received ICI-chemo.