Programmed cell death 1 inhibitors with or without concurrent brain radiotherapy for lung cancer patients with brain metastases

Abstract

Background: Data focusing on the synergistic effect of programmed cell death 1 (PD-1) inhibitors and brain radiotherapy for brain metastases (BMs) in lung cancer is scarce. Methods: A total of 60 lung cancer patients receiving PD-1 inhibitors with or without brain radiotherapy were identified in this retrospective study. The primary endpoints were intracranial progression-free survival (iPFS), extracranial progression-free survival (PFS), and overall survival (OS) among three groups. Results: Twenty-one patients received PD-1 inhibitors and concurrent brain radiotherapy, 20 patients were treated with PD-1 inhibitors and non-concurrent brain radiotherapy, and the other 19 patients were treated with PD-1 inhibitors alone. Patients in the concurrent group achieved a higher intracranial objective response rate (iORR, 61.1% vs. 29.4% vs. 25.0%) and a higher intracranial disease control rate (iDCR, 83.3% vs. 58.8% vs. 56.3%) compared with those in the non-concurrent group and PD-1 inhibitors alone group. The median iPFS was significantly longer in the concurrent group than the non-concurrent group and the PD-1 inhibitors alone group (9.8, 5.7, and 4.8 months, P=0.039, respectively). The median PFS were 9.2, 5.7 and 4.6 months (P=0.347) in the concurrent group, non-concurrent group and PD-1 inhibitors alone group. And the median OS were not reached, 12.1 and 6.9 months (P=0.206), respectively. Multivariate analysis revealed that the lack of concurrent brain radiotherapy was independently associated with a shorter iPFS. Conclusions: PD-1 inhibitors with concurrent brain radiotherapy achieved a higher iORR, iDCR, and iPFS in lung cancer patients with treated or newly diagnosed BMs.