« Thyroid drug in short supply | Home | Hydroxychloroquine May Help Delay Skin Damage In SLE Patients. »

Osteoporosis drugs may reduce breast cancer risk

By jeremyc | March 3, 2010

Source: MedWire News

Women who use biphosphonate drugs to prevent and treat osteoporosis may have a lower risk for breast cancer than non-users, according to a study by US researchers.

“Because we were able to account for important confounders, these findings may reflect real benefits due to the anti-tumor mechanisms of these medications,” remark Polly Newcomb (Fred Hutchinson Cancer Research Center) and colleagues in the British Journal of Cancer.

Bisphosphonates are primarily used for the prevention and treatment of osteoporosis, but have also been shown to directly induce tumor apoptosis, inhibit angiogenesis, and prevent tumor cell adhesion, explain the researchers.

To evaluate whether the use of these drugs may be associated breast cancer, Newcomb and team conducted a case-control study in Wisconsin from 2003 to 2006. They interviewed 2936 women with breast cancer and 2975 population-based controls about their history of fractures, whether they had been diagnosed with osteoporosis, and their history of bisphosphonate use.

After adjusting for potential confounders such as family history of breast cancer, age at first birth, postmenopausal hormone use and body mass index, the researchers found that current bisphosphonate users had a 33% reduced risk for breast cancer compared with non-users. Moreover, increasing duration of use was significantly associated with a greater reduction in risk.

Of note, the protective effect seemed limited to 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,” Newcomb said.

The researchers note that the molecular targets of biphosphonates are unknown. However, “in a recent clinical trial of early-stage breast cancer, nitrogen-containing bisphosphonates seemed to improve long-term outcomes, and several large clinical trials are currently underway to clarify this issue,” they report.

Newcomb and co-authors conclude that their results “are suggestive of an additional benefit of the common use of bisphosphonates, in this instance, the reduction in breast cancer risk.”

Topics: | Breast cancer, Osteoporosis |

Comments are closed.