Real-world patterns of endocrine therapy for metastatic hormone-receptor-positive (HR+)/human epidermal growth factor receptor-2-negative (HER2−) breast cancer patients in the United States: 2002–2012

Abstract

Fewer than two thirds of patients initiated treatment for HR+/HER2- mBC with ET. Among those who did, most received only one line of ET before discontinuation or transition to CT. Patients who received multiple lines of ET experienced shorter durations of therapy with each line. Real-world treatment with ET falls short of the targets recommended by guidelines, representing unmet need for treatment options that improve the effectiveness of endocrine therapy.