Today, a new clinical trial evaluating a novel approach to breast cancer prevention launched in the United States and Canada. Called the ExCel research study, this is the first North American clinical trial to evaluate the role of an aromatase inhibitor in the prevention of breast cancer.
Coordinated by the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG), the ExCel research study will examine the potential benefit of exemestane and its ability to prevent breast cancer in women who are at increased risk for the disease. Exemestane -- part of a class of drugs called aromatase inhibitors -- suppresses estrogen production, a key component in the development of some types of breast cancer. Exemestane could provide women with an alternative option to tamoxifen, the only drug FDA approved for prevention of breast cancer.
"Breast cancer is a major public health issue -- every 30 seconds somewhere in the world a woman is diagnosed with this disease," says Dr. Paul Goss, the ExCel research study chair. "Thousands of women have already beat breast cancer thanks to recent research on aromatase inhibitors. As a result, we think this could be an effective approach to preventing it from developing in the first place."
The ExCel research study will follow more than 4,500 postmenopausal women from the U.S., Canada and Spain over a five year period. To be eligible, women must be 35 years of age or older and have an increased risk of developing breast cancer. Risk factors can include a woman's age, her family history of breast cancer, her age at first menstrual period and her age at first live birth.
Initial results of the trial could be available within four years and study investigators hope to see as much as a two-thirds reduction in the incidence of breast cancer among women in the treatment group.
Aromatase inhibitors are currently being used to treat breast cancer in women around the world and results from a study published in a March 2004 issue of the New England Journal of Medicine demonstrated that exemestane can prevent the occurrence of new cancers in the opposite breast of women who have already had breast cancer, suggesting that it may also be able to prevent the disease in healthy women.
Clinical studies have also shown that aromatase inhibitors are associated with fewer serious side effects than tamoxifen, the only other drug available to women for primary breast cancer prevention.