A new study has revealed that a drug the fights bone loss in women may also have side benefits for fighting breast cancers that are sensitive to estrogen, reducing the chance that the cancer will either spread or return to the body once it is gone. Furthermore, researchers said that the effects stayed around for years after the treatment of the drug, called Zometa, ends.

“I find that very reassuring”, said Dr. Michal Gnant of the Medical University of Vienna in Austria. “It obviously demonstrates that we can impact on the long-term outcome of our patients with early intervention. We do not have to give these drugs forever. I’m very enthusiastic about this”.

In the study, 1,803 premenopausal women that had an early-stage estrogen-sensitive breast cancer were given a drug that repressed estrogen production in the ovaries in addition to drugs that help prevent cancers from growing on estrogen. Half of the women were randomly assigned to also take infusions of Zometa every six months for three years.

Two years after all the treatments had ended, those who had the infusions of the bone drug had a 32% less chance of having their cancer return, compared with those who only took estrogen suppression medications.