A study found that the bone-strengthening medicine Actonel (chemical name: risendronate) can improve bone health after chemotherapy for breast cancer and can minimize the bone weakening that can happen when hormonal therapy is used after chemotherapy.
This was a small study involving 87 postmenopausal women. All of the women had received chemotherapy as part of their breast cancer treatment plan. Some (13%) of the women were also treated with an aromatase inhibitor, a type of hormonal therapy, after their chemotherapy. About half of the women were treated with Actonel, which was taken by mouth once a week for 24 months. The others were treated with a placebo.
When this study started, the researchers measured the strength of the spine and hip bones of each woman by determining the bone mineral density, or BMD, of those bones. Bone mineral density decreases when bones weaken and increases when bones strengthen. After 24 months of receiving Actonel or placebo, the researchers again measured the bone mineral density at the hip and spine and compared those measurements to those obtained at the start of the study.
The bone health of the women who were treated with Actonel benefited from that treatment. But the benefit was different depending on whether or not the women were being treated with an aromatase inhibitor.
Among the women who had received chemotherapy but were not on an aromatase inhibitor, treatment with Actonel over 24 months improved bone health:
- The bone density of women who did not get Actonel didn't change at the spine and decreased 1.2% at the hip.
- The bone density of women who were treated with Actonel increased 2.1% at the spine and 2.2% at the hip.
Among the women who had received chemotherapy and were being treated with aromatase inhibitor, treatment with Actonel over 24 months minimized bone weakening:
- The bone density of women who did not get Actonel decreased 4.8% at the spine and decreased 2.8 percent at the hip.
- The bone density of women who were treated with Actonel decreased 2.4% at the spine and didn't change at the hip.
Estrogen plays an important role in bone health. Because of the unintended effects of chemotherapy on the ovaries, many women treated with chemotherapy for breast cancer will undergo menopause and experience a decline in estrogen levels. This decline in estrogen levels can lead to bone weakening and increase a woman's risk of developing osteoporosis and bone fractures.
Hormonal therapy is often used after breast cancer chemotherapy to further lower the chances of the cancer coming back. The aromatase inhibitors, which work by limiting any remaining production of estrogen after menopause, can further increase bone weakening and the risk for osteoporosis and bone fractures. The aromatase inhibitors are Arimidex (chemical name: anastrozole), Aromasin (chemical name: exemestane), and Femara (chemical name: letrozole).
Actonel, the medicine evaluated in this research, belongs to a group of bone-strengthening medicines called bisphosphonates. Other bisphosphonates are:
- Boniva (chemical name: ibandronate)
- Fosamax (chemical name: alendronate)
- Reclast (chemical name: zoledronic acid)
Reclast is given intravenously once a year. Like Actonel, the others are pills taken by mouth.
If chemotherapy or an aromatase inhibitor (or both) is part of your breast cancer treatment plan, you should talk to your doctor about your bone health. Ask your doctor about monitoring your bone health during and after treatment. Also ask whether treatment with a bone-strengthening medicine such as Actonel or one of the other bisphosphonate medicines might help improve your bone health or at least minimize the negative effects of treatment on your bones. In addition to medical treatment, there are a number of nutrition and lifestyle changes that you can take to improve the health of your bones. Visit the Bone Health section to learn about these changes and much more about bone health.