Abstract P5-11-20: Efficacy observation of 306 patients with fulvestrant 500mg treatment in hormone-receptor positive HER2 negative metastasis breast cancer, a real world study

Background: Fulvestrant 500mg has been proved better efficacy in breast cancer with hormone receptor positive (HR+),and then become an optional strategy for primary or second line treatment of HR+ positive metastasis breast cancer (MBC). Methods: In this real world study, we retrospectively analyzed the patients with HR+ HER 2 negative MBC who received fulvestrant 500mg treatment at Beijing cancer hospital during January 2015 to December 2018. Clinical benefit rate (CBR), progression free survival (PFS), overall survival (OS) and adverse events were investigated. Results: There were 306 patients enrolled, median age was 48.7(range 20-75) years, median line of fulvestrant was 2.11(range 1-6), 68.3%(209/306) patients were involved with visceral metastasis. The CBR was 68.6%, median PFS was 8.41m (95%CI: 7.079m-9.743m, range 0.89m-80.16m). Among the patients received fulvestrant at the first line, the PFS was 10.55m(95%CI:6.46m-14.64m, range 0.92m-34.3m). The median OS hasn’t been obtained. In subgroup analysis, the patients without liver metastasis(12.49m vs. 4.60m, p4, 12.65m vs. 7.72m vs. 3.98m respectively, p2 lines, 14.06m vs. 7.79m vs. 3.52m respectively, p Conclusions: Fulvestrant was an effective and safe regimen in endocrine therapy for hormone receptor positive HER2 negative MBC. The patients who were in first line treatment, absence of liver metastasis and small tumor burden might be more benefit from fulvestrant. Corresponding authors: Huiping Li, huipingli2012@hotmail.com; Guohong Song, songguohong918@hotmail.com, Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Breast Oncology, Peking University Cancer Hospital & Institute, 52 Fucheng Rd, Beijing 100142, China Citation Format: Wen Lei, Huiping Li, Guohong Song, Ruyan Zhang, Ran Ran, Ying Yan. Efficacy observation of 306 patients with fulvestrant 500mg treatment in hormone-receptor positive HER2 negative metastasis breast cancer, a real world study [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-11-20.