ABREAST: a prospective, real-world study on the effect of nab-paclitaxel treatment on clinical outcomes and quality of life of patients with metastatic breast cancer

Abstract

Purpose The efficacy of nab-paclitaxel in patients with metastatic breast cancer (MBC) has been demonstrated in randomized clinical trials. However, real-world evidence on effectiveness remains limited. Patients and methods The primary objective of this multicenter prospective study was to assess the overall response rate (ORR) of patients with MBC treated with nab-paclitaxel. Secondary objectives included progression-free survival (PFS), overall survival (OS) and quality of life, assessed with the Functional Assessment of Cancer Therapy-Breast (FACT-B) instrument. Results Eligible patients (N = 150; 36% with de novo MBC presentation) with a median age of 64.5 years were enrolled (86% were ER+, 33.3% (50/150) were ≥ 70 years of age and 53% were treated in the third or later line of treatment). A median of 6 cycles were administered but 26% of patients required dose reduction due to toxicity. The ORR was 26.7% [95% confidence interval (CI) 19.6–33.7], the median PFS was 6.2 months (95% CI 5.2–7.3), and the median OS 21.1 months (95% CI 17.2-not estimable). There was no statistical significant difference in the median PFS of patients < and ≥ 70 years of age. The patients’ baseline FACT-B total score remained unchanged. The serious and non-serious adverse event incidence rates were 13% and 48%, respectively. Conclusions This prospective study provides further evidence on quality of life, efficacy, and safety of nab-paclitaxel in patients with MBC and sheds more light in special subpopulations such as the elderly and those treated beyond the second line.