Phase II study of whole brain radiotherapy with or without erlotinib in patients with multiple brain metastases from lung adenocarcinoma

Hongqing Zhuang,^1–4 Zhiyong Yuan,^1–4 Jun Wang,^1–4 Lujun Zhao,^1–4 Qingsong Pang,^1–4 Ping Wang<sup>1–4

1</sup>Department of Radiotherapy, Tianjin Medical University Cancer Institute and Hospital, ²National Clinical Research Center of Cancer, ³Tianjin Key Laboratory of Cancer Prevention and Therapy, ⁴Tianjin Lung Cancer Center, Tianjin, People’s Republic of China

Abstract: The aim of this paper is to explore the efficacy of whole brain radiotherapy (WBRT) versus WBRT concurrent with erlotinib in patients with multiple brain metastases of lung adenocarcinoma. WBRT was administered at 30Gy/10f in both arms. In the combination arm, 150 mg erlotinib was given each day, starting the first day of radiotherapy and continuing for 1 month following the end of radiotherapy. Thereafter, pemetrexed or docetaxel monotherapy or the best supportive therapy was given to both arms. The intracranial objective response rate and the local progression-free survival (LPFS) were primary endpoints. Toxicity, progression-free survival (PFS) and overall survival (OS) were secondary endpoints. Thirty-one patients in the WBRT group and 23 patients in the combination group were enrolled from November 2009 to December 2011. In the WBRT and the combination arms, respectively, the objective response rate was 54.84% and 95.65% (P = 0.001), the median local progression-free survival was 6.8 months and 10.6 months (P = 0.003), the median PFS was 5.2 months and 6.8 months (P = 0.009), and median OS was 8.9 months and 10.7 months (P = 0.020). In the combination group, there were no differences of LPFS, PFS, and OS between the epidermal growth factor receptor (EGFR) mutation patients and EGFR wild-type patients. No Grade 4 or higher side effects were observed in either group. A multivariate analysis indicated that erlotinib was the most important prognostic factor for a prolonged survival. Data showed that erlotinib in combination with WBRT had a tolerable toxicity profile and prolonged the LPFS, PFS, and OS of lung adenocarcinoma patients with multiple brain metastases compared with WBRT monotherapy.

Keywords: WBRT, tyrosine kinase inhibitor, radiosensitizer, erlotinib