Unexpected benefit for bone drug in breast cancer patients

The serendipitous result of a clinical trial shows that a drug given to breast cancer patients to maintain their bone density actually increased their survival rate. Seven years after the initial treatment, women who received an intravenous injection of the bone density drug Zometa had a significantly lower risk of death than those who received only the standard of care.

Researchers led by a doctor at Austria s Medical University of Vienna treated 900 premenopausal early-stage breast cancer patients with a twice-yearly infusion of the bisphosphonate Zometa over the course of three years. (Bisphosphonates work by slowing bone erosion, increasing bone density, and decreasing the amount of calcium the bones release into the blood.) After treatment with Zometa, the women had surgery followed by hormone blockers; the control group received the same treatments, but without the zoledronic acid (Zometa). After seven years of follow-up, the researchers found that those women who received the Zometa infusions not only had stronger bones but, compared to women in the control group, also had a 37 percent lower risk of death a magnitude, in fact, that is comparable to many chemotherapy treatments.

Currently, the researchers have no solid explanation for the remarkable effects of Zometa. However, they note that postmenopausal women in another, larger study benefited only when they were well past menopause. This piece of information, combined with the fact that the women in the first group were on hormone blockers, suggests that Zometa works best in women with very low estrogen levels.

ACSH's Dr. Gilbert Ross was impressed by the results of the study, but says that a larger study should be done before a regimen of Zometa becomes a conventional treatment. The study author claimed that this infusion should now be the standard of care. Well, despite this hopeful report and the lack of serious side-effects, these results must be confirmed by independent research before such a statement can be entertained.