Breast Cancer Drug May Reduce High-Risk Sign of Density

Mammograms, such as the one shown here, were used to measure the effects of the drug exemestane in a Lombardi Comprehensive Cancer Center study. In addition to preventing breast cancer, the drug also appears to reduce breast density in high-risk postmenopausal women.

May 17, 2011 – An ongoing study at Georgetown’s Lombardi Comprehensive Cancer Center shows that a drug that may prevent breast cancer in high-risk postmenopausal women also appears to reduce mammographic breast density in that group of women.

Having dense breast tissue is considered one of the strongest predictors of breast cancer.

The study, a joint project between Lombardi and the Center for Cancer Research at the National Cancer Institute, examines the effect of exemestane (Aromasin®) on breast density.

Density Decrease

“Overall, we saw a 7 percent decrease in mammographic density among the women,” said Dr. Jennifer Eng-Wong, an assistant professor at Lombardi, a part of Georgetown University Medical Center.

Eng-Wong, the lead study author, refers to a preliminary analysis conducted for the first 23 (of 42) participants in the study. Mammograms were taken before the women began taking exemestane and one year after treatment started, with breast density compared between the two mammograms for each woman.

“Previous studies with [this type of medication] have not shown a significant decline in mammographic density, and differences in result may be due to duration of treatment or baseline characteristics of the study population,” Eng-Wong said.

Treatment Options

The doctor explained the earlier studies with tamoxifen, an FDA-approved drug designed to reduce breast cancer in high-risk women, also showed a reduction in breast density with that medication. In those studies, a 10 percent drop in breast density correlated with a 50 percent drop in beast cancer.

But tamoxifen has rare yet serious side effects, resulting in a need for other treatment options such as exemestane.

Other authors of the study include doctors Claudine Isaacs, Robert Warren, Philip Cohen and Celia Byrne of Lombardi, as well as NCI authors David Venzon, Suparna Wedam, Jo Anne Zujewski and Larissa Korde.

The NCI Intramural Research Program and Lombardi funded the research.