Bisphosphonates play a role in reducing recurrent breast cancer....

We know that bisphosphonates (also called diphosphonates) are a class of drugs that prevent the loss of bone mass, used to treat osteoporosis and similar diseases. Bone has constant turnover, and is kept in balance (homeostasis) by osteoblasts creating bone and osteoclasts digesting bone. Bisphosphonates inhibit the digestion of bone by osteoclasts. Osteoclasts also have constant turnover and normally destroy themselves by a process called cell suicide (apoptosis). Bisphosphonates encourage osteoclasts to undergo apoptosis. Though other uses like in he treatments of osteoporosis, osteitis deformans, bone metastasis, primary multiple myeloma,hyperparathyroidism and osteogenesis imperfecta were known. A new data suggests that these agents may play a role in reducing recurrent breast cancer as well. Zoledronic acid (see the structure) is both safe and effective in preventing bone loss in postmenopausal women with breast cancer who are treated with aromatase inhibitors, according to data presented at the CTRC-AACR San Antonio Breast Cancer Symposium. Women who take aromatase inhibitors need some sort of bone protection, and this five-year data show that zoledronic acid is a viable option.

As per the claim by the researchers lead by Dr. Adam Brufsky , women who are on Medicare tend to go with tamoxifen because the cost of anastrozole puts them squarely in the donut hole of Medicare Part D, but once the cost barrier is removed there will likely be a mass switch to the aromatase inhibitor, which will necessitate the need for bone protection. More interestingly, in the same conference a research group lead by Rowan Chlebowski presented a study wherein "women who used bisphosphonates, had significantly fewer invasive breast cancers than women who did not use bisphosphonates. .......

http://www.upci.upmc.edu/news/upci_news/121009_study.cfm