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08/03: BC Cancer Agency offering an international breast cancer prevention study to women
ExCel Trial launched at BC Cancer Agency’s Vancouver Centre
(Please see www.excelstudy.com for more information.)
Postmenopausal women who have an increased risk for developing breast cancer are being sought to participate in an international prevention study at the BC Cancer Agency. This study will test a breast cancer medication to see if it can prevent cancer in otherwise healthy, but high-risk women.
The BC Cancer Agency’s centres in Vancouver and Kelowna are offering the ExCel trial, which has just opened in Vancouver. Researchers hope to recruit more than 4,500 women from Canada, the United States and Spain over a five-year period for the National Cancer Institute of Canada trial, funded in part by the Canadian Cancer Society.
Women who agree to enroll will receive a placebo or the drug exemestane (Aromasin®) for up to five years in this randomized, double-blind study. Exemestane is an aromatase inhibitor, a class of drugs used to treat breast cancer. This is the first time it is being tested as a preventative agent in a large-scale clinical trial.
“We know that by maintaining a healthy body weight through regular exercise and eating a balanced diet, women may reduce their risk of developing breast cancer,” says Dr. Karen Gelmon, principal investigator of the trial. “However, because many cancers still occur in women with healthy lifestyles, drugs like exemestane may provide another promising option to reduce some women’s risk of getting the disease.”
Aromatase inhibitors work by limiting the body’s ability to produce estrogen. Estrogen plays a key role in the development and growth of most types of breast cancer and it is believed the inhibition of estrogen may prevent some breast cancers.
Results from a study published in the 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 prevent the disease in healthy women.
Karen Kirkpatrick, a 57 year-old legal assistant, has two sisters who are survivors of breast cancer, which places her at higher risk for developing the disease. She is participating in the STAR breast cancer prevention trial (comparing the drugs raloxifene and tamoxifen) which enrolled more than 100 women in B.C.
“Studies like these are important, because they give women an opportunity to help themselves, and other women through the information gained from the trial, and all it takes is a little bit of time,” says Kirkpatrick. “I was closely monitored while on the trial, and had access to the best doctors and care possible. So, it’s really a win-win for everyone.”
To be eligible for the study, women must be postmenopausal, have no prior diagnosis of invasive breast cancer, and have an increased risk of cancer as determined by such factors as age, family history, personal medical history, age at first menstrual period, age at first child’s birth, or results of prior breast biopsies. Women who consent to the study will undergo an initial assessment including a mammogram, bone density test, and blood tests. Subsequently, they will meet annually with a clinical team for an examination and follow-up tests.
Breast cancer is the most widely diagnosed cancer in women, and the second leading cause of cancer death (lung cancer is number one). In B.C. it is estimated that 2,700 women will be diagnosed with breast cancer this year, and 630 women will die from it.
Breast cancer prevention strategies have enormous potential to reduce mortality from the disease. The BC Cancer Agency’s breast cancer research program focuses on prevention – stopping the disease from taking root – as well as finding more effective treatments for those who already have it.
Women living in the Greater Vancouver area can contact the BC Cancer Agency’s Clinical Trials Group at 604.675.8230, or e-mail prevent@bccancer.bc.ca
Women living in the Southern Interior can call 250.712.3966, local 7047 or e-mail CSIprevent@bccancer.bc.ca
The BC Cancer Agency, an agency of the Provincial Health Services Authority, is committed to reducing the incidence of cancer, reducing the mortality from cancer, and improving the quality of life of those living with cancer. It provides a comprehensive cancer control program for the people of British Columbia by working with community partners to deliver a range of oncology services, including prevention, early detection, diagnosis and treatment, research, education, supportive care, rehabilitation and palliative care. The BC Cancer Foundation supports research and care enhancements at the BC Cancer Agency.
For more information, please contact:
Papinder Rehncy
Public Relations, BC Cancer Agency
604.877.6261; pager 604.918.1043
prehncy@bccancer.bc.ca
Backgrounder:
Information supplied by National Cancer Institute of Canada, Clinical Trials Group
What is the Excel Research Study?
The ExCel research study is a phase III breast cancer prevention clinical trial. It is a new and important international clinical trial designed to determine whether exemestane can prevent breast cancer in healthy postmenopausal women who have an increased risk for developing breast cancer.
The ExCel research study is coordinated by the National Cancer Institute of Canada Clinical Trials Group in cooperation with healthy women and cancer centres in Canada, the United States, and Spain.
What is exemestane?
Exemestane was approved by the U.S. Food and Drug Administration in 1999 and by Health Canada in 2000 for the treatment of advanced breast cancer in postmenopausal women whose tumours have stopped responding to tamoxifen therapy. Exemestane is marketed by Pfizer, Inc. as Aromasin. It is also approved for use in Europe, Japan, and South America.
Results of the Intergroup Exemestane Study, published in the New England Journal of Medicine, revealed that 32 percent fewer women had a recurrence in their breast cancer when they switched to exemestane after two to three years of tamoxifen compared to those who continued on tamoxifen for a total of five years, the current standard of care. Additionally, twice as many women receiving tamoxifen developed second (or new) breast cancers than those treated with exemestane.
Unlike other aromatase inhibitors, exemestane is a steroidal aromatase inactivator, which means it selectively targets and irreversibly binds to the aromatase enzyme, which is required to produce estrogen. Without estrogen, breast cancer cells cannot survive. Exemestane is well-tolerated and the side-effects associated with the treatment are generally predictable and manageable. Given its potent suppression of estrogen, exemestane has been associated with low instances of mild nausea and hot flashes.
Why can’t premenopausal women participate in Excel?
Exemestane is one member of a class of drugs called aromatase inhibitors. Exemestane, given alone, is not recommended in premenopausal women for two reasons:
1) Aromatase inhibitors work against breast cancer by suppressing the body’s ability to produce estrogen. In post-menopausal women, estrogen is still produced in the body’s fat, skin and muscle and it can be fully suppressed by the inhibitors.
In pre-menopausal women, estrogen production comes mainly from the ovaries and the inhibitors cannot adequately suppress this.
2) By partially, but inadequately, suppressing estrogen from the ovaries, the inhibitors cause a reflex stimulation by hormones from the pituitary gland in the brain. This over stimulates the ovaries, and can cause ovarian cysts, pain and discomfort. It can also result in an increase in fertility and an unwanted pregnancy.
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