Key clinical point: In patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer (BC), adding endocrine therapy (ET) to dual anti-HER2 targeted therapy after chemotherapy improved progression-free survival (PFS) without increasing the rate of adverse events.
Major finding: There was a significant improvement in 5-year PFS with vs without the addition of ET (hazard ratio 0.59; P = .031). Nausea and vomiting were more common in patients who did not vs did receive ET ( 21% vs 7%; P = .010).
Study details: This study analyzed the real-world data of 147 patients with HER2+/HR+ metastatic BC from a prospective registry who received first-line chemotherapy plus trastuzumab and pertuzumab with (n = 91) or without (n = 56) concurrent ET.
Disclosures: This study did not receive any funding. Some authors declared serving on the advisory board for or receiving research funding, speaker honoraria, or travel grants from several sources.
Source: Loft M et al. Addition of endocrine therapy to dual anti-HER2 targeted therapy in initial treatment of HER2 + /HR + metastatic breast cancer. Breast Cancer Res Treat. 2023; 198:67-74 (Jan 9). Doi: 10.1007/s10549-022-06856-1