Bisphosphonates are medicines that help build bone mineral density and strengthen bone. When breast cancer travels to the bone, it can weaken them and may cause them to become brittle.

A Phase III study has reported that two years after starting bisphosphonate treatment, women who took Zometa went longer without bone difficulties that those who took Aredia.

The study compared the effectiveness of the two bisphosphonate medications to see which worked better when given over a two year period. The results, after 13 months, showed Zometa did better than Aredia at reducing overall risk of weakening, pain or fracture of bone.

The two year results showed that those who were treated with Zometa had a 45 percent average reduction annually in the number of bone weakening, pain or fractures compared to Aredia.

The most important part is what this can mean for you -- This study suggests that Zometa may be a viable long-term option for women with ER+ advanced breast cancer to the bone. If you have ER- disease, this study suggests you may receive an equally good result from Zometa or Aredia.