Combination of Aromatase Inhibitors with Metronomic Capecitabine: A New Chemoendocrine Treatment for Advanced Breast Cancer

Abstract

Purpose : Endocrine therapy is one of the main treatment options for hor mone receptor (HR)-positive advanced breast cancer (ABC). However, whether the combination of endocrine therapy with chemotherapy is practicable and more effective than endocrine therapy alone remains unknown. The aim of this study was to investigate the clinical efficacy of the aromatase inhibitors (AIs) combined with metronomic capecitabine to provide the clinical evidence for further research in patients with HR-positive ABC. Methods : Data from 407 patients with HR-positive ABC were retrospectively analyzed. A total of 305 patients were given AIs alone, and 102 patients were given AIs plus capecitabine as first-line treatment. Progression-free survival (PFS) was the primary endpoint. Results : The median follow-up for all patients was 47.0 months (range, 3 - 119 months). The median overall survival (OS) and PFS were 52.0 months and 24.2 months, respectively. The median PFS in the combination group was significantly longer than that in the AIs group (22.0 months vs . 14.0 months, p = 0.002). Additionally, patients in the combination group had significantly longer OS than patients in the AI group (66.0 months vs . 49.0 months, p = 0.003). Multivariate analysis showed that combination therapy was a significant favorable predictor for PFS and OS. Furthermore, young age (<40 years), low estrogen receptor (ER) expression level (<40%), presence of visceral metastasis, prior adjuvant AI use and long disease-free interval (DFI) (>24 months) improved the benefit from combination therapy. Conclusions : AIs plus metronomic capecitabine significantly improves PFS and OS in patients with HR-positive ABC. Thus, chemo-endocrine therapy should be further explored.