According to a panel of experts convened by the American Society of Clinical Oncology (ASCO), a type of medicine that strengthens bones should be given to women with breast cancer only when cancer has spread and begun to destroy bone.
Due to the high cost of the therapy and the lack of evidence that it prolongs survival, the panel advises against using the treatment to prevent bone loss in breast cancer patients whose bones have not yet been damaged.
When breast cancer spreads, or metastasizes, it commonly invades the bones, leading to frequent fractures and severe bone pain. Research has shown that bisphosphonates can relieve pain and prevent fractures by slowing the rate of bone destruction in women with breast cancer.
Despite these improvements in quality of life, however, the drugs have not been shown to prolong a woman's life, according to the panel. To best determine which women should receive the medications, the experts reviewed the research on the use of bisphosphonates in breast cancer patients.
The panel advises that a bisphosphonate called pamidronate be given to women whose breast cancer has spread to the bones and who have clear signs of bone destruction. Although there is no evidence that such therapy improves survival, it may prevent fractures, pain and other bone-related complications, according to the report. But in women who have an abnormal bone scan, but show no signs of bone destruction on other tests, there is not enough evidence to justify using bisphosphonates, according to the panel. Likewise, the panel advises that women whose cancer has spread elsewhere in the body -- but not to the bones -- should not be given bisphosphonates.
Referring to pamidronate, which is one of two intravenous bisphosphonates approved to treat bone cancer. This drug is being viewed as a major advance in a primary complication in breast cancer, but the researchers found that there was no foundation upon which to support its use in patients other than those who have radiographic evidence of bone metastases." In the report, the panelists point out that the cost of pamidronate is considerably higher than the cost of treating bone-related complications. According to ASCO, each treatment of the drug, which is given once a month, costs about $700.
Journal of Clinical Oncology 2000;18:1378-1391