Bone drug works for breast cancer survivors
NEW YORK (Reuters Health) - Risedronate, better known by the brand name Actonel, is effective for maintaining or improving the bone strength of women who have had chemotherapy for breast cancer, researchers report.
They explain in the Journal of Clinical Oncology that add-on chemotherapy has prolonged survival for women with breast cancer. However, chemotherapy brings on early menopause, which leads to the bone-thinning disease osteoporosis and to bone fractures.
To investigate the usefulness of risedronate in combating these effects, Dr. Susan L. Greenspan of the University of Pittsburgh and colleagues assigned 87 women who had undergone chemotherapy to take risedronate or a placebo once a week.
Many of the women in the study were also taking a so-called aromatase inhibitor such as letrozole to reduce the odds of a cancer relapse, and this made a difference to bone density.
For example, by the end of the 24-month study, women in the placebo group had a significant reduction in bone density of 4.8 percent at the spine and 2.8 percent at the hip if they were on an aromatase inhibitor. Those in the placebo group who were not taking an aromatase inhibitor maintained bone density at the spine, but had a significant 1.2 percent loss at the hip.
For women given risedronate, spine bone density fell by 2.4 percent and remained stable at the hip if they were also taking an aromatase inhibitor. The greatest improvement was seen in women on risedronate who were not taking an aromatase inhibitor: spine bone density rose by 2.1 percent and there was a 2.2 percent increase at the hip.
Risedronate "proved to be effective with or without the use of an aromatase inhibitor," Greenspan and her colleagues conclude.
Further studies, they add, are needed to see whether these improvements in bone density "translate to fracture reduction for these patients."
SOURCE: Journal of Clinical Oncology, June 1, 2008.
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Bone drug works for breast cancer survivors
The research reviewed here 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.