An Evolving Role of Antitumor Activity of Zoledronic Acid in Breast Cancer

Abstract

Breast cancer patients with bone metastases benefit from bisphosphonates by reducing fracture risks, spinal cord compression, and hypercalcemia caused by bone metastases. Traditionally, zoledronic acid has been administered on a monthly schedule via intravenous injection. It has been demonstrated in preclinical studies that zoledronic acid can inhibit tumor cell invasion, adhesion, and angiogenesis. The anti-tumor effects and bone health benefits of zoledronic acid therapy have been demonstrated in several clinical studies conducted with postmenopausal women during adjuvant breast cancer treatment at various timings and schedules. According to several observations and postmenopausal data, zoledronic acid’s anticancer activity may be affected by the endocrine environment. It appears zoledronic acid may be most effective for improving disease-free survival in women who are postmenopausal or have endocrine therapy-induced menopause in the adjuvant setting. In general, zoledronic acid is most effective when initiated early, concomitantly with adjuvant therapy. Still, zoledronic acid’s relative potency and the most effective schedule of treatment remain unclear. To examine the effectiveness of zoledronic acid therapy in patients with breast cancer, we reviewed existing clinical studies.