January 7, 2015
Extra Benefit for Bisphosphonates? Protection Against Endometrial Cancer

Detroit—Bisphosphonates used to treat osteoporosis and other bone conditions may have an unintended benefit for women: reducing the risk of developing endometrial cancer by about half compared to women who do not use the drugs.

That’s according to a new analysis published online by the journal CANCER. It bolsters previous research indicating an anticancer effect for that type of medication.

Background in the study, led by researchers from the Henry Ford Health System in Detroit, notes that endometrial cancer makes up nearly half of all of gynecologic cancers diagnosed in the United States. It is the fourth most common malignancy in women, and the eighth most common cause of cancer death.

Preclinical studies have indicated that bisphosphonates have antitumor effects, including the ability to keep tumor cells from multiplying and from invading normal tissues.

To look at the ability of bisphosphonates to help prevent endometrial cancer, the researchers evaluated information on nearly 30,000 women from the National Cancer Institute's PLCO (Prostate, Lung, Colorectal, and Ovarian) Screening Trial, which included questionnaires about bone medication use. Only data for bisphosphonates that contain nitrogen were evaluated, because those are known to have stronger anticancer activity.

Results indicate that bisphosphonate users were half as likely to develop endometrial cancer as those not using the medications. The incidence rate for endometrial cancer among women exposed to nitrogenous bisphosphonates (NBPs) was 8.7 per 10,000 person-years versus 17.7 per 10,000 person-years among never-exposed women, according to the results.

“The results of the current study suggest that use of NBPs may have a protective effect on the incidence of endometrial cancer. However, additional studies are needed that include other potential confounders and a larger sample,” the authors conclude.

“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,” added lead author Sharon Hensley Alford, PhD. “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.”

U.S. Pharmacist Social Connect