Activity of fulvestrant versus exemestane in advanced breast cancer patients with or without visceral metastases: data from the EFECT trial

Purpose Patients with visceral metastases (VM: lung and/or liver metastases) are generally regarded as being less responsive to hormonal therapy, and chemotherapy often becomes the default treatment. This paper reports a subgroup analysis from EFECT (The Evaluation of Faslodex versus Exemestane Clinical Trial) examining the efficacy of fulvestrant and exemestane in patients with or without VM. Methods EFECT is a randomised, double-blind, multicentre, Phase III trial in postmenopausal women with advanced breast cancer progressing or recurring after prior non-steroidal aromatase inhibitor therapy. Results Overall, approximately 57% of patients in EFECT had visceral involvement. Fulvestrant and exemestane demonstrated clinical benefit in 29.1% and 27.2% of patients with VM, respectively. Median duration of response was 13.5 vs 10.8 months and median duration of clinical benefit was 9.9 vs 8.1 months, respectively. Conclusions These results encourage the use of endocrine agents such as fulvestrant in treating patients with advanced breast cancer and VM.