Clinical effect of whole brain radiotherapy for brain metastases from lung adenocarcinoma in patients with or without EGFR mutations / 中华放射肿瘤学杂志

ABSTRACT

Objective To compare the clinical effect of whole brain radiotherapy (WBRT) for brain metastases from lung adenocarcinoma between patients with and without epithelial growth factor receptor (EGFR) mutations.Methods A retrospective analysis was performed for 89 patients with brain metastases from lung adenocarcinoma who were treated in our hospital from August 2010 to May 2015.EGFR testing was performed in all patients.WBRT (6-MV external X-ray beam) was performed at 30 Gy in 10 fractions or 40 Gy in 20 fractions;for patients with ≤3 brain metastases, simultaneous integrated boost intensity-modulated radiotherapy was performed at 40-45 Gy in 10 fractions or 50-60 Gy in 20 fractions.The response rate, intracranial progression-free survival (IPFS), and overall survival (OS) were compared between patients with EGFR mutations and patients with wild-type EGFR.The Kaplan-Meier method was used to calculate IPFS and OS, the log-rank test was used for survival difference analysis and univariate prognostic analysis, and the Cox model was used for multivariate prognostic analysis.Results For these 89 patients, the overall response rate was 62%, the median IPFS was 7.0 months (95%CI6.060-7.940), and the median OS was 12.0 months (95%CI9.539-14.465).The univariate and multivariate analyses showed that the response rate was associated with Karnofsky Performance Scale (KPS) score and EGFR mutation status (P=0.009 and 0.035);KPS score and EGFR mutation status were significant prognostic factors for IPFS (P=0.048 and 0.000);KPS score and primary tumor control were significant prognostic factors for OS (P=0.000 and 0.031).Conclusions After WBRT for brain metastases from lung adenocarcinoma, the patients with EGFR mutations have a higher response rate and a longer IPFS compared with those with wild-type EGFR, but there is no significant in OS between the two groups of patients.