Bisphosphonates are medications commonly used to treat osteoporosis and other bone conditions but a new analysis suggests that women who use bisphosphonates also have about half the risk of developing endometrial cancer as women who don't use the drugs.
Endometrial cancer, which arises in the lining of the uterus, accounts for nearly 50 percent of gynecologic cancers diagnosed in the United States, and it is the fourth most common malignancy in women and the eighth most common cause of cancer death.
While bisphosphonates are known to prevent bone loss, preclinical studies have shown that the medications also have antitumor effects, including the ability to keep tumor cells from multiplying and from invading normal tissues.
To assess whether bisphosphonates might help prevent endometrial cancer, Sharon Hensley Alford, PhD, of the Henry Ford Health System in Detroit, led a team that evaluated information from the National Cancer Institute's PLCO (Prostate, Lung, Colorectal, and Ovarian) Screening Trial, which included questionnaires about bone medication use.
The researchers analyzed data for only those bisphosphonates that contain nitrogen as these are known to have stronger anticancer activity.
In the study published in Cancer, a total of 29,254 women were included in the analysis. After accounting for factors including age, race, history of hormone therapy use, smoking status, and body mass index, bisphosphonate users were half as likely to develop endometrial cancer.
"Other studies have shown that bisphosphonates may reduce the risk of certain cancers, but we are the first to show that the risk for endometrial cancer may also be reduced," said Dr. Alford. "This study suggests that women who need bone strengthening medications and who have increased risk for endometrial cancer may want to choose the nitrogen form of bisphosphonates because this form may reduce the risk of endometrial cancer."