Abstract
IntroductionThis study aimed to evaluate the therapeutic effect of osimertinib and further to compare the results of osimertinib plus brain radiation vs. osimertinib monotherapy in advanced EGFR-mutant non-small cell lung cancer (NSCLC) patients with brain metastases (BMs).MethodsA retrospective study was conducted involving 62 advanced EGFR-mutant NSCLC patients with BMs who were treated with first-line osimertinib at the Vietnam National Cancer Hospital between April 2019 and December 2023. Patients were categorised in two treatment groups: (1) osimertinib alone (33 patients) and (2) osimertinib combined with locoregional therapy, including stereotactic radiosurgery or whole-brain radiotherapy (29 patients). Endpoints included objective response rate (ORR), central nervous system response rate (CNS-ORR), progression-free survival (PFS), overall survival (OS).ResultsThe systemic ORR was 91.9% and the disease-control rate (DCR) was 96.8%. The CNS-ORR was 91.9% and the CNS-DCR was 100%. The median PFS and median OS achieved were 24.5 and 35.2 months, respectively. There was no significant difference in outcomes between patients in either treatment group with respect to CNS-ORR ( P = 1.0), mean best percentage change from baseline in CNS target lesion size (P = .376), median PFS (P = .656), intracranial progression-free survival (iPFS) (P = .706), or OS (P = .734). The occurrence of any-grade adverse events (AEs) did not differ significantly between the two treatment groups (P = .762). However, in the osimertinib plus brain radiation cohort, 3/29 (10.3%) patients experienced radiotherapy-related AEs (2 cases of brain necrosis, 1 case of leukoencephalopathy), which consisted of one case of grade 3 brain radiation necrosis.ConclusionOsimertinib shows favorable real-world outcomes in improving PFS, OS, and CNS-ORR in advanced EGFR-mutant NSCLC Vietnamese patients with BMs, with no clear additional benefit from combining with brain radiotherapy.