Pembrolizumab plus bevacizumab achieves long-term progression free survival in patients with lung adenocarcinoma with brain metastases: a case report and literature review

Abstract

Abstract Background: Brain metastases (BMs) are an important cause of mortality in lung cancer. Tyrosine kinase inhibitor (TKI) based targeted therapy is recommended for driver gene mutation, non-squamous NSCLC with more than three BMs. For BMs without driver gene mutation, radiotherapy and systemic chemotherapy are standard treatments. However, radiotherapy results in neurocognitive impairment. Chemotherapeutic drugs have difficulty in crossing the blood-brain barrier. Case presentation: This case was driver gene mutation negative, programmed-death-ligand-1 (PD-L1) positive lung adenocarcinoma with mildly symptomatic BMs, without a driver gene mutation. The patient benefited from treatment with a non-chemotherapy regimen of pembrolizumab plus bevacizumab. Intracranial edema and tumor enhancement were significantly reduced, and headache was alleviated after two cycles of treatment. Partial remission was achieved in BM after 10 cycles of treatment. As of May 2023, the patient had achieved >32 months of progression-free survival. Conclusions: The combination of immune-checkpoint inhibitors and antiangiogenic agent might be a valuable therapeutic choice for patients with driver gene mutation negative, PD-L1 positive NSCLC with asymptomatic or mildly symptomatic BMs.