A single-centre, retrospective, observational analysis of fulvestrant for recurrent/metastatic breast cancer according to metastatic site

Abstract

Background/Aim: Factors influencing fulvestrant efficacy may be useful in selecting the optimal treatment regimen for postmenopausal Japanese women with metastatic/recurrent HR-positive, HER2-negative breast cancer. Patients and Methods: We retrospectively evaluated progression-free and overall survival (PFS and OS) in 100 fulvestrant-treated patients according to metastatic site. Results: Median PFS was significantly better in patients with non-visceral (bone and regional metastases; 22.8 months) vs. visceral metastasis (lung, liver, and other organs; 8.2 months; p=0.024), although median OS did not differ (p=0.922). Median PFS in patients with lung metastasis (20.8 months) and non-visceral metastasis (22.8 months) were comparable; patients with liver metastasis (6.1 months) and other organ metastases (3.7 months) had worse prognoses. Conclusion: Patients with non-visceral metastases had a better prognosis than those with visceral metastases. Fulvestrant induced a longer PFS in patients with non-visceral metastasis, and also in those with lung metastasis without liver or other organ involvement.