FRIDAY, March 5, 2010 (HealthDay News) -- Some types of bone-building drugs used to prevent and treat osteoporosis might reduce the risk of breast cancer, according to new research.
The study, which included 6,000 Wisconsin women aged 20 to 69, found that those who took bisphosphonate drugs such as Fosamax, Boniva and Zometa for more than two years were 40 percent less likely to develop breast cancer than were women who did not take the drugs.
However, the protective effective was seen only among women who were not obese.
"Obese women may have elevated estrogen levels, so underlying hormones may influence the ability of bisphosphonates to reduce breast cancer risk," the study's lead author, Polly Newcomb, head of the cancer prevention program at Fred Hutchinson Cancer Research Center in Seattle, said in a news release from the center.
The study is published online and in the March print issue of the British Journal of Cancer.
Just how bisphosphonate drugs affect the risk for breast cancer is unclear, but there are a number of possibilities.
"These drugs may affect cell function and be important in cell growth and death -- specifically the death of tumors or even premalignant disease," Newcomb said.
Also, previous studies have found that some kinds of bisphosphonates trigger tumor cell death, prevent tumors from establishing a blood supply and prevent cancer cells from binding to each other.
More information
The U.S. National Cancer Institute has more about breast cancer prevention.
