Breast cancer prevention study launches in Canada and US

Breast cancer prevention study launches in Canada and US
March 30, 2005

A major clinical trial looking at a new way to prevent breast cancer is being launched today in Canada and the United States. Coordinated by the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG), and funded in part by the Canadian Cancer Society, the ExCel research study will test whether the drug exemestane can help prevent breast cancer in women who are at increased risk for the disease. Exemestane (a member of a class of drugs called aromatase inhibitors) suppresses estrogen production, a key component in the development of some types of breast cancer. Pfizer manufactures exemestane and is also supporting the study and providing the drug for the trial. ‘Breast cancer is a major public health issue. Every 30 seconds somewhere in the world a woman is diagnosed with this disease,’ said Dr. Paul Goss, the ExCel research study chair. ‘Recent research on aromatase inhibitors is already helping many women reduce their risk of breast cancer recurrence. We therefore think this could be an effective approach to preventing it from developing in the first place.’ 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 the women taking exemestane, said Goss. The ExCel research study will follow more than 4,500 postmenopausal women from Canada, the United States 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 her first child’s birth. The trial design includes a quality of life component and a number of sub-studies are also planned that will evaluate topics such as the impact of physical activity on reducing breast cancer risk, as well as cognitive function and bone density of women during menopause. Aromatase inhibitors are currently being used to treat breast cancer recurrence in women around the world. Results from a study published in a March 2004 issue of the New England Journal of Medicine demonstrated that exemestane was able to 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 the primary prevention of breast cancer. ‘While tamoxifen has already been shown to reduce the incidence of primary breast cancer, many women choose not to take this drug because of its known side effects,’ said Goss, also the director of breast cancer research at the Massachusetts General Hospital and professor of medicine at Harvard Medical School. ‘Results of this study will provide women with important information about another potential tool for breast cancer prevention that could offer greater benefits and with fewer side effects.’ Dr. Barbara Whylie, CEO of the Canadian Cancer Society, said, ‘Research already suggests that diet and exercise may be effective ways women can reduce their risk of breast cancer – a disease we know takes a tremendous toll on Canadian women and their families. We’re looking forward to the results of this research and the possibility of providing women with another option for breast cancer prevention.’ Breast cancer is the most commonly diagnosed cancer and the second most common cause of cancer death in Canadian women. An estimated 21,200 women were diagnosed with breast cancer in Canada in 2004. An estimated 5,200 women died in Canada last year from the disease. The National Cancer Institute of Canada Clinical Trials Group, based at Queen’s University in Kingston, Ont. and funded by the Canadian Cancer Society, is working in cooperation with physicians in Canada, the United States and Spain to coordinate the ExCel research study. Women looking for more information about the ExCel research study and participating study centres in their community can visit www.excelstudy.com or call toll-free: In Canada, the Canadian Cancer Society’s Cancer Information Service: 1 888 939-3333 In the U.S., the National Cancer Institute’s Cancer Information Service: 1-800-4-CANCER

Source: The Canadian Cancer Society