Is There Still a Role for Endocrine Therapy Alone in HR+/HER2- Advanced Breast Cancer Patients? Results from the Analysis of Two Data Sets of Patients Treated with High-Dose Fulvestrant as First-Line Therapy in the Real-World Setting: The EVA and GIM-13 AMBRA Studies

Background: Different studies suggest that fulvestrant 500 mg every 28 days (HD-FUL) could be an active treatment in HR+ advanced breast cancer (ABC) patients even treated with aromatase inhibitors in the adjuvant setting. The aim of this analysis is to describe the outcome of ABC patients treated with HD-FUL as first-line treatment in terms of median duration of treatment and the overall response rate in a real-world setting. Methods: For the purpose of the present analysis, we considered two data sets of HR+ ABC patients collected in Italy between 2012 and 2015 (EVA and GIM-13 AMBRA studies). Results: Eighty-one and 91 patients have been identified from the two data sets. The median age was 63 years (range 35–82) for the EVA and 57.8 years (range 35.0–82.3) for the AMBRA patients. ORRs were 23.5 and 24.3% in the whole population, 26.9% in the patients with bone only, and 21.8 and 21.4% in those with visceral metastases. The median duration of HD-FUL was 11.6 months (range 1–48) and 12.4 months (range 2.9–70.0) in the two data sets, respectively. Conclusion: These data suggest that HD-FUL should still continue to play a significant role as first-line therapy in HR+ ABC patients.