1357P - Bevacizumab improved prognosis for advanced EGFR mutant lung adenocarcinoma with brain metastasis receiving cerebral radiotherapy

Background

Cerebral radiotherapy can reduce recurrence and improve overall survival (OS) in patients with brain metastasis (BM) from Epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma. Bevacizumab (Avastin), an anti-Vascular endothelial growth factor (VEGF) monoclonal antibody, angiogenesis inhibition and alleviates blood-brain barrier (BBB) damage and brain edema through its blocking VEGF. However, whether bevacizumab combined with cerebral radiotherapy can further increase the efficacy and improve the prognosis of patients is unclear. This study aimed to evaluate the effect of bevacizumab on OS in BM patients with EGFR mutation-positive non-small cell lung cancer (NSCLC) undergoing cerebral radiotherapy.

Methods

A total of 178 patients with EGFR-mutant lung adenocarcinoma and BM who received cerebral radiotherapy met the inclusion criteria for this retrospective study, including 70 patients in the bevacizumab treatment group and 108 in the non-bevacizumab group. The Kaplan-Meier method was used for survival analysis. Univariate and multivariate analyses were performed to identify EGFR-mutated BM prognostic factors for these patients. Cerebral radiotherapy included whole-brain radiotherapy (WBRT), local radiotherapy, and WBRT + Boost.

Results

At the end of the last follow-up period, 176 patients (74.3 %) had died, and the median OS was 33.25 months. We observed a significant difference in the median OS between the bevacizumab and non-bevacizumab groups (45.8 months vs 32.0 months, P =0.007). Patients treated with bevacizumab after cerebral radiotherapy had a longer median OS than patients treated with bevacizumab before cerebral radiotherapy (59.4 months vs 33.7months, P=0.0198).

Conclusions

Bevacizumab could improve OS in BM patients with EGFR mutation-positive NSCLC receiving cerebral radiotherapy. This improvement was more obvious after cerebral radiotherapy, possibly as a result of bevacizumab alleviating radiation brain necrosis caused by brain radiotherapy.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.