Effect of brain radiotherapy strategies on prognosis of patients with EGFR-mutant lung adenocarcinoma with brain metastasis

Guangchuan Deng,Jiaojiao Ke,Zhenxiang Li,Jianbin Li,Yingyun Zhang,Hongyue Qin,Qi Wang

doi:10.1186/s12967-021-03161-1

Abstract

PurposeEpidermal growth factor receptor (EGFR)-mutant lung cancers have a high risk of developing brain metastases (BM). Whole brain radiotherapy (WBRT), local radiotherapy, and WBRT + Boost are frequently used for treatment of BM. This retrospective study aimed to evaluate the difference in efficacy of these radiotherapy modes in patients with EGFR-mutant lung adenocarcinoma with BMs. Further, we determined the optimal radiotherapy regimen for patients based on Lung-molGPA.Methods and materialsWe retrospectively enrolled 232 patients with EGFR-mutant lung adenocarcinoma with BMs. Patients were divided into three groups based on the different modes of brain radiotherapy: WBRT group, local radiotherapy group, and WBRT + Boost group. Graded prognostic assessment for lung cancer using molecular markers (Lung molGPA), overall survival (OS), and intracranial progression-free survival (iPFS) were calculated. Kaplan–Meier was used to compare iPFS and OS in different groups.ResultsThe median OS for the WBRT (n = 84), local radiotherapy (n = 65), and WBRT + Boost (n = 83) cohorts was 32.8, 59.1, and 41.7 months, respectively (P = 0.0002). After stratification according to the Lung-molGPA score, the median OS for the WBRT (n = 56), local radiotherapy (n = 19), and WBRT + Boost (n = 28) cohorts was 32.5, 30.9, and 30.8 months, respectively, in subgroup with score 1–2 (P = 0.5097). In subgroup with score 2.5–4, the median OS for the WBRT (n = 26), local radiotherapy (n = 45), and WBRT + Boost (n = 54) cohorts was 32, 68.4, and 51 months, respectively (P = 0.0041).ConclusionThe present study showed that in patients with EGFR-mutant lung adenocarcinoma with BM, local radiotherapy and WBRT + Boost perform similarly well both in the subgroups with low and high scores of Lung-molGPA. Considering the side effect caused by whole brain radiotherapy, we recommended local radiotherapy as optimal brain radiation mode for those subtype lung cancer patients.

Highlights

Advanced lung adenocarcinoma is increasingly being treated with individualized molecular targeted therapy based on gene aberrations, and the mutant epidermal growth factor receptor (EGFR) is the most common therapeutic target [1,2,3]
After stratification according to the Lung-molGPA score, the median overall survival (OS) for the whole brain radiotherapy (WBRT) (n = 56), local radiotherapy (n = 19), and WBRT + Boost (n = 28) cohorts was 32.5, 30.9, and 30.8 months, respectively, in subgroup with score 1–2 (P = 0.5097)
Considering the side effect caused by whole brain radiotherapy, we recommended local radiotherapy as optimal brain radiation mode for those subtype lung cancer patients

Summary

Introduction

Advanced lung adenocarcinoma is increasingly being treated with individualized molecular targeted therapy based on gene aberrations, and the mutant epidermal growth factor receptor (EGFR) is the most common therapeutic target [1,2,3]. Radiotherapy targeting local metastases can reduce radiation damage to the surrounding normal brain tissue, and reduces neurotoxicity It can only target metastases in the radiation field, is limited to improve the control effect of multiple intracranial metastases, and is recommended only for a limited number of BMS (1 to 4) [19]. Some studies have suggested that WBRT + Boost is superior to WBRT in lung cancer patients with craniocerebral metastasis. Those studies involved in mixed pathological type especially small cell lung cancer and did not take gene status into account to determine the therapy choice. Those studies involved in mixed pathological type especially small cell lung cancer and did not take gene status into account to determine the therapy choice. [14, 20, 22]

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Discussion

Conclusion