Real-world data of fulvestrant as first-line treatment of postmenopausal women with estrogen receptor-positive metastatic breast cancer

Abstract

Goals of endocrine therapy for advanced breast cancer (ABC) include prolonging survival rates, maintaining the quality of life, and delaying the initiation of chemotherapy. We evaluated the effectiveness of fulvestrant as first-line in patients with estrogen receptor (ER)-positive ABC with relapse during or after adjuvant anti-estrogenic therapy in real-world settings. Retrospective, observational study involving 171 postmenopausal women with ER-positive ABC who received fulvestrant as first-line between January 2011 and May 2018 in Spanish hospitals. With a median follow-up of 31.4 months, the progression-free survival (PFS) with fulvestrant was 14.6 months. No differences were seen in the visceral metastatic (14.3 months) versus non-visceral (14.6 months) metastatic subgroup for PFS. Overall response rate and clinical benefit rate were 35.2% and 82.8%. Overall survival was 43.1 months. The duration of the clinical benefit was 19.2 months. Patients with ECOG performance status 0 at the start of treatment showed a significant greater clinical benefit rate and overall survival than with ECOG 1–2. Results in real-world settings are in concordance with randomized clinical trials. Fulvestrant continues to demonstrate clinical benefits in real-world settings and appears be well tolerated as first-line for the treatment of postmenopausal women with ER-positive ABC.

Promising Therapeutic Impact of a Selective Estrogen Receptor Downregulator, Fulvestrant, as Demonstrated In Vitro upon Low-Grade Serous Ovarian Carcinoma Cell Lines

“…Fulvestrant has been used as a first-line treatment to meet the targets of endocrine therapy, including extending survival rates, maintaining the quality of life, and delaying the initiation of chemotherapy in patients with advanced ER-positive breast cancer [ 58 ]. Despite the established efficiency of hormonal therapy, one in three patients developed resistance in one study [ 59 ].…”

Breast Cancer Stem-Like Cells in Drug Resistance: A Review of Mechanisms and Novel Therapeutic Strategies to Overcome Drug Resistance

“…ER signaling plays a crucial role in BC proliferation, invasion, and angiogenesis. Mechanisms, through which the endocrine therapy works (refer to Table 1 ), can be categorized into (1) SERMs, (2) aromatase inhibitors (AIs), (3) CDK4/6 inhibitors, and (4) SERDs ( Figure 4D ) ( 148 , 149 ). SERMs function by sitting in the ER of breast tissues, blocking the estrogen from interacting with the ER, and hence the cells can no longer grow and multiply ( 150 ).…”

“…Fulvestrant is a selective estrogen receptor degrader (SERD) administered in both first and subsequent lines of treatment in ER-α+ metastatic BC patients ( 149 , 168 ). Fulvestrant competitively inhibits estrogen to occupy the ER, eventually promotes degradation of the receptor, and thus interferes with estrogen signaling in breast tumor tissues ( 169 ).…”

Adverse event signal mining and serious adverse event influencing factor analysis of fulvestrant based on FAERS database

“…Fulvestrant inevitably causes drug-related adverse reactions while treating breast cancer. A review of medical records of 171 patients with locally advanced or metastatic HR+/HER2- breast cancer who received fulvestrant treatment showed that 66.9% of patients experienced drug-related adverse reactions, with severe adverse reactions accounting for 8.6% of cases 8 . In recent years, there has been growing concern about adverse reactions in endocrine therapy for breast cancer.…”