Adetunji T. Toriola, MD, PhD, MPH, Washington University School of Medicine, St. Louis, MO


Studies have shown that women with dense breasts are at increased risk for breast cancer. The drug tamoxifen has been shown to reduce breast cancer risk in high-risk women in part by reducing breast density. The purpose of this study is to see whether the drug denosumab (Prolia), which is used to treat osteoporosis, can reduce breast density. If the drug reduces breast density, it could provide a new treatment option for risk reduction.

What does participation involve?
If you sign up to be in this study, the research team will contact you to ask you questions about your medical history to determine if you are a good fit. They will take time to answer any questions you have about the study. They will also ask for your most recent mammogram results so that they can learn about your breast density.

If you are eligible to participate, you will be asked to go to the Siteman Cancer Center to complete a one-time 10-minute questionnaire and take a pregnancy test. You will be randomly assigned (like with the flip of a coin) to the group that will receive denosumab or to the group that will receive a placebo. The drug or placebo (saline) will be injected into your upper arm at the start of the study. You will receive a second injection 6 months later. You will continue with your routine mammograms at the start of the study, 1 year after you received the injection, and 2 years after you received the injection. You may also have a mammogram 3 years after you received the injection. The research team will give you calcium and vitamin D supplements to take daily for 12 months. You will receive a breast biopsy and give a blood sample at the start of the study and one year later. You may stop taking part in the study at any time for any reason.

Washington University School of Medicine and Siteman Cancer Center, St. Louis, MO

How can I sign up for this study?

You can sign up for this study if you match all of these main criteria. Please read this list carefully.

  • You have never had ductal carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS), invasive breast cancer, or other cancer (non-melanoma skin cancer is OK)
  • You are a woman age 40 or older
  • You are pre-menopausal
  • You live near or are willing to travel to St. Louis, MO
  • You are not pregnant or planning to become pregnant
  • You have no history of osteoporosis
  • If you have undergone genetic testing, you have no known BRCA mutations


For more information on the study, visit: https://toriolalab.wustl.edu/research/mammographic-and-breast-density-studies/the-rankl-study/. Contact the study team at 314-747-9992 or .

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