breast, cancer, prevention, bisphosphonates

The use of bisphosphonates does not appear to reduce the risk of developing breast cancer among postmenopausal women. These results, which are contrary to results from previous observational studies, were published in the journal JAMA Internal Medicine.

Bisphosphonates are agents that protect bone density, and are often used among women with osteoporosis. Prior results from studies based on observation indicated that the use of bisphosphonates might confer a protective effect against breast cancer.

Researchers recently evaluated data from two randomized, double-blind, placebo-controlled trials referred to as the FIT and HORIZON-PFT trials. The trials included nearly 14,000 postmenopausal women: half of the women received bisphosphonates for a year while the other half received placebo. Patients who had ever been diagnosed with breast cancer were excluded from participating in the trial. Follow-up was approximately 3 years.

There were no differences in breast cancer incidence between women who received bisphosphonates, compared to those who did not receive bisphosphonates.
These results remained true whether the FIT and HORIZON-PFT trials were evaluated separately or together.
Furthermore, the data did not change regardless of the bisphosphonate used (alendronate or zoledronic acid).
The researchers concluded that “These 2 randomized clinical trials do not support the findings from observational research. Contrary to the results from observational studies, we found that 3 to 4 years of bisphosphonate treatment did not decrease the risk of invasive postmenopausal breast cancer.”

Reference: Hue T, Cummings S, Caule J, et al. Effect of bisphosphonate use on risk of postmenopausal breast cancer. Results from the randomized clinical trials of alendronate and zoledronic acid. JAMA Internal Medicine. Early on-line publication.DOI:10.1001/jamainternmed.2014.3634.Available at: