Studies: Bone drugs may help prevent breast cancer

New results from a large women's health study suggest that bone-building drugs such as Fosamax and Actonel might help prevent breast cancer.

Women who already were taking these medicines when the study began were nearly one-third less likely to develop breast cancer over the next seven years. That's compared to women who were not on such pills.

The study by itself is not proof that these drugs can prevent cancer. More definitive studies should give a clearer picture in a year or two. Until then, doctors say women should only take these drugs if they have osteoporosis or other bone problems.

However, doctors are excited because it fits with other research last year that found one of these bisphosphonate drugs cut the chances that cancer would come back in women already treated for the disease.

"Now we're actually looking at this in the general population - healthy women who have never had breast cancer. And it looks like it's protective in those women as well," said Dr. Peter Ravdin of the University of Texas Health Science Centre at San Antonio.

"There's a strengthening story here," he said. "This is very promising."

The new results were presented Thursday at the San Antonio Breast Cancer Symposium. They come from more than 151,000 participants in the Women's Health Initiative, a study known for revealing previously unrecognized risks from taking estrogen and progestin pills after menopause.

Fosamax is made by Merck.