Outcome of patients (pts) with brain metastases (BMs) from HER2-positive breast cancer (BC) treated with lapatinib plus capecitabine (LC).

Abstract

1155 Background: In the present analysis we investigated retrospectively the efficacy of LC for BMs from HER2+ BC. Secondly, we evaluated the clinical outcome of HER2+ BC pts with BMs treated with LC. Methods: Out of the 81 HER2+ metastatic BC pts treated with lapatinib (1,250 mg p.o. daily) plus capecitabine (2,000 mg/mq p.o. dd 1-14 every 21) at two Italian institutions, we identified 34 pts with evidence of BMs prior to the start of LC. Only pts naïve for both lapatinib and capecitabine were included, which left a total of 30 pts available for the analysis. In a second step, we compared the overall survival (OS) from the development of BMs of these 30 pts vs. a group of 23 pts who had received only trastuzumab-based therapies beyond brain progression. Results: The median age of the 30 LC-treated pts was 45 years (range 24-75). All of them had received prior treatment with a taxane, an anthracycline, and trastuzumab (median no. of trastuzumab-based therapies for metastatic BC=2). 26/30 pts had received prior radiotherapy for BMs. In 6/30 pts LC was delivered as first systemic treatment after the development of BMs, whereas in 24/30 pts it was administered following one trastuzumab-based therapy. In the 22 patients with BMs evaluable for response (one or more progressive BMs ≥ 1 cm; WBRT and/or SRS received ≥ 3 months prior to LC), 7 PR (32%) and 6 SD (27.5%) were observed with LC. The median duration of brain response was 6 months (range 3-25). The median brain progression-free survival was 5.6 months (95% CI, 4.4-6.8) and the percentages of pts without brain progression at 2, 4, and 6 months were 83.3%, 60%, and 45.9%, respectively. The median OS (from the start of LC) was 11 months (95% CI, 4.3-17.6). When comparing the OS (as assessed from the time of development of BMs) of these 30 pts with that of 23 pts treated only with trastumumab-based therapies beyond brain progression, a significantly higher OS was observed in favor of the LC-treated pts (27.8 months vs. 16.7 months, respectively; p=0.01). Conclusions: LC is active for established BMs from HER2+ BC in pts who are naïve for either lapatinib and capecitabine. Using LC after the development of BMs appears to improve OS vs. receiving only trastuzumab-based therapy. No significant financial relationships to disclose.