Anti-osteoporosis drugs bisphosphonates may help reduce breast cancer risk?

A new study published in the Aug 2010 issue of Journal of Clinical Oncology suggests that anti-osteoporosis drugs bisphosphonates may help reduce the risk of breast cancer.

Bisphosphonates are a class of drugs indicated to treat osteoporosis, and prevent and treat skeletal lesions due to malignancy, according to the background information in the study report.  

The study led by Rennert G and colleagues from Carmel Medical Center in Haifa, Israel showed women who were on bisphosphonates for no shorter than one year were 28 percent less likely to develop breast cancer compared to controls.

It should be noted that this study is not a trial, meaning that taking bisphosphonates may not becessarily reduce the breast cancer risk. It may be something else associated with use of the anti osteoporosis drugs that is responsible for the preventaive effect.

For the Breast Cancer in Northern Israel Study, the researchers examined data on use of bisphosphonates in 4,039 postmenopausal patients and controls who were members of Clalit Health Services.

They found study subjects who used bisphosphonates for longer than one year before diagnosis of breast cancer, but not for shorter than one year, was linked with a 39 percent reduced risk compared to controls.

The reduction in breast cancer risk was still 28 percent even after adjustment for other factors including age, fruit and vegetable consumption, sports activity, family history of breast cancer, race, body mass index, and taking calcium supplements, use of hormone replacement therapy, number of pregnancies, months of breastfeeding and age at first pregnancy.

Bisphosphonates are risky drugs.  Recently, the U.S. Food and Drug Administration has warned that using bisphosphonates for a long term such as five years or longer may boost risk of leg fractures in osteoporosis patients.

The current study found taking bisphosphonates for more than one year did not increase any additional benefit, the reduction in breast cancer risk was still 28 percent in postmenopausal women.

Additionally, the researchers found breast cancer diagnosed in users of bisphosphonates was more often estrogen receptor positive and less often poorly differentiated, meaning that women with tumors developing under bisphosphonates tended to have a favorable prognosis.

Breast cancer is diagnosed in more than 170,000 women and kills about 50,000 each year in the United States, according to American Cancer Society. One in seven women in the country will be diagnosed with this disease sooner or later in their lifetime.

More reports will be published here in the National Breast Cancer Awareness month to help reader better understand the risk of breast cancer and possible preventative measures against the disease.

Jimmy Downs