Cancer: New Drug Deters Breast Cancer Relapses (cont.)
A form of hormone therapy for the treatment of breast cancer, letrozole works by limiting the ability of an enzyme called aromatase to produce estrogen, a major growth stimulant in many breast cancers.
Mayo Clinic medical oncologist James Ingle , M.D., says, "Based on our findings, all post-menopausal women with hormone-receptor positive tumours completing about five years of tamoxifen should discuss taking letrozole with their doctors to reduce their risk of breast cancer recurrence." Ingle, from Rochester, Minn., led the research study in the United States.
With Canadian Cancer Society funding, the clinical trial was coordinated by the National Cancer Institute of Canada Clinical Trials Group at Queen's University, in partnership with the U.S. National Cancer Institute and its Clinical Trials Cooperative Groups. Novartis, which manufactures letrozole, also known as Femara®, provided the drug for the trial.
Women participated in the study for an average of 2.4 years and for as long as five years. The study found that women taking letrozole had a reduction in the number of recurrences of cancer in their previously affected breast, a reduction in the number of new cancers in their opposite breast, and a reduction in the spread of the cancer outside their breast.
The side effects of letrozole, a pill which is taken once a day, are very similar to those experienced by women undergoing menopause. They were generally mild in study participants. Women in the study will continue to be followed to more thoroughly assess any effects of long-term use of letrozole on bone strength or other organs. Until these are known, patients should be monitored closely.
"The Canadian Cancer Society is pleased to have made a key contribution to this study," says Barbara Whylie, M.D., director of Cancer Control Policy for the Canadian Cancer Society. "We estimate that more than 20,000 Canadian women will be diagnosed with breast cancer this year and just over half of those are going to be eligible for this drug. That means these women will have a significantly improved hope for a future without cancer."
"This large trial only began in 1998 and we already have important results that will change clinical practice," says Jeffrey Abrams, M.D., coordinator of the U.S. National Cancer Institute's Cooperative Group breast cancer treatment trials. "This is a tribute to the patients and physicians who participated since their efforts will now have a positive impact on so many lives."
Participants in the clinical trial were enrolled through hospitals, cancer centers and institutes throughout Canada, the United States, England, Belgium, Ireland, Italy, Poland, Portugal and Switzerland. The European Organization for Research and Treatment of Cancer and the International Breast Cancer Study Group coordinated the European component of the trial.
The Canadian Cancer Society is the largest charitable funder of cancer research in Canada. It funds clinical trials research through its support of the National Cancer Institute of Canada Clinical Trials Group.
Source: National Cancer Institute, National Institutes of Health, Press Release, October 9, 2003
Last Editorial Review: 10/10/2003