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

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; erlotinib; radiosensitizer; tyrosine kinase inhibitor.

Figures

Figure 1

The LPFS, PFS, and OS of WBRT group versus WBRT+erlotinib group. Notes: The median LPFS, PFS, and OS were 6.8 months (range, 0–18.7 months), 5.2 months (range, 0–14.7 months), and 8.9 months (range, 4.5–19.7 months), respectively, in the WBRT group and 10.6 months (range, 4.9–20.7 months), 6.8 months (range, 1.5–20.7 months), and 10.7 months (range, 5.3–29.7 months), respectively, in the combination group. There were statistically significant differences in the LPFS, PFS, and OS between the groups. Abbreviations: CI, confidence interval; HR, hazard ratio; LPFS, local progression-free survival; OS, overall survival; PFS, progression-free survival; WBRT, whole brain radiotherapy.

Figure 2

The LPFS, PFS, and OS of EGFR mutation patients versus EGFR wild-type patients in the combination arm. Notes: In the combination group, 12 patients had no exons mutations; 11 patients had 19/21 exons mutations, and no patients had k-ras mutations. The median LPFS, PFS, and OS were 9.6 months (range, 6.9–16.4 months), 7.5 months (range, 6.2–16.1 months), and 10.2 months (range, 7.1–16.5 months), respectively, in the EGFR wild-type group and 11.2 months (range, 4.9–20.7 months), 6.1 months (range, 3.2–20.7 months), and 11.5 months (range, 5.3–29.7 months), respectively, in the EGFR mutation group. There were no statistically significant differences in the LPFS, PFS, and OS between the two groups. Abbreviations: CI, confidence interval; HR, hazard ratio; LPFS, local progression-free survival; MT-EGFR, mutation-type EGFR patients; OS, overall survival; PFS, progression-free survival; WT-EGFR, wild-type EGFR patients; EGFR, epidermal growth factor receptor.