The U.S. National Cancer Institute halted a $100 million study of drugs designed to prevent breast cancer in women at risk for the disease.
The study couldn't be justified amid questions of cost, safety and overall benefit, the institute announced Tuesday.
The dangers of introducing these drugs, with their many known side effects, outweighs their potential," the institute said.
While proponents argued the study was crucial to determining the best drugs to prevent breast cancer, other advocacy groups called for more research to better identify women who would benefit most.
The study would have tested a new generation of drugs known as aromatase inhibitors, The Washington Post reported Wednesday. Under the study, about 12,800 women in the United States and Canada would have received raloxifene or the aromatase inhibitor letrozole.
About 180,000 American women are diagnosed with breast cancer each year and about 40,000 die from the disease, making breast cancer the second most common cancer in women.
Copyright 2007 by United Press International
Explore further: In search of a treatment for a rare bone cancer