An interim analysis of a breast cancer prevention study using exemestane (Aromasin®) finds an "acceptable" level of bone loss.

The ongoing phase II study details reported today, by Jennifer Eng-Wong, MD, a breast cancer specialist at Georgetown's Lombardi Comprehensive Cancer Center at the San Antonio Breast Cancer Symposium, examines the use of exemestane in postmenopausal women who are at an increased risk of developing breast cancer based on commonly used risk assessment measures. In addition to exemestane, all the study participants received calcium carbonate and vitamin D.

Wong's report represents findings from a planned interim safety analysis in 18 women who completed one year of exemestane.

"We found a drop in bone mineral density in these women similar to what we've seen in women taking exemestane in the adjuvant treatment setting." Eng-Wong reports. "Like aromatase inhibitors in the adjuvant setting there is a small amount of bone loss in the spine and hip. The long term clinical impact of the small decrease is not known."

The exemestane study continues with endpoints including bone density measurements and change in breast density over two years of treatment. Dense breasts as observed on a mammogram are associated with an increase in a woman's risk of developing breast cancer.

Source: Georgetown University