The use of Zoledronic Acid for the Prevention of Bone Loss in Women Receiving Letrozole (or ZOFAST Study)

24 February 2013


This study examined the use of Zoledronic acid (also called Zoledronate) in the prevention of cancer treatment-induced bone loss in postmenopausal women receiving letrozole as adjuvant therapy for early breast cancer.

Scientific Title

An Open-Label, Randomized, Multicenter Study to Evaluate the Use of Zoledronic Acid in the Prevention of Cancer Treatment-Related Bone Loss in Postmenopausal Women with ER+ and/or PgR+ Breast Cancer Receiving Letrozole as Adjuvant Therapy.


Bone health is important for women who are diagnosed with breast cancer as all women (particularly postmenopausal women) are at some risk of osteoporosis (loss of bone strength or density).  Hormonal or endocrine treatments (called aromatase inhibitors) may reduce the density of bone and increase fracture risk in women receiving these drugs.

Results: Adding a drug to protect the bone (called a bisphosphonate), improves bone density, and reduces the risk of fracture in women with breast cancer. An unexpected finding was that Zoledronate (given six-monthly during letrozole treatment), also reduces the risk of breast cancer recurring. A large amount of research continues to be done looking at the anti-cancer effect of bisphosphonate drugs.

Main Publication

Zoledronic Acid for Postmenopausal Women With Early Breast Cancer Receiving Adjuvant Letrozole (ZO-FAST Study): Final 60- Month Results. Coleman, Robert; de Boer, Richard; Eidtmann, Holger; Llombart-Cussac, Antonio; Davidson, Neville; Neven, Patrick; von Minckwitz, Gunter; Sleeboom, Harm; Forbes, John; Barrios, Carlos; Frassoldati, Antonio; Campbell, Ian; Paija, Outi; Martin, Nicolas; Modi, Ankur; Bundred, Nigel; accepted Annals of Oncology; February 2013; 24 (2); 398-405