No Power Line-Cancer Link Sustained

Six years of research have produced little hard evidence that the magnetic fields around electric power lines cause cancer, yet some lingering concerns remain, a National Institutes of Health division reported yesterday.

"Virtually all of the laboratory evidence in animals and humans and most of the mechanistic studies in cells fail to support a causal relationship" between the electromagnetic fields and cancer, the National Institute of Environmental Health Sciences said in the report to Congress.

However, it said there have been some statistical associations between the fields and childhood leukemia as well as chronic lymphocytic leukemia in adults exposed to the fields through their work, such as electric utility workers, machinists and welders.

Research is continuing on these "lingering concerns" and efforts to reduce human exposure to electromagnetic fields should continue, the report said.

NIEHS Director Kenneth Olden said that since virtually everyone is routinely exposed to EMF, efforts to reduce exposure should continue. For example, the electrical industry should continue efforts to reduce the electromagnetic fields around large transmission lines and communities should enforce electrical codes to avoid wiring errors that can increase EMF.

Drug Reduces Breast Cancer Risk

An estrogen substitute used to prevent brittle bones in women who are past menopause reduces the risk of breast cancer dramatically, a study found.

The three-year study of 7,705 women found a 76 percent lower risk of breast cancer among those taking raloxifene compared with those given a placebo.

Raloxifene is marketed under the name Evista by Eli Lilly and Co., which paid for the study. It is part of a new generation of drugs that scientists hope will mimic the good effects of estrogen -- stronger bones and a lower risk of heart disease -- while inhibiting the possible harmful effects, which may include promoting breast and uterine cancer. Raloxifene is not risk-free; it increases the chances of serious blood clots.

In the new study, led by Steven R. Cummings of the University of California at San Francisco, 5,129 postmenopausal women younger than 81 received raloxifene daily, while 2,576 got a dummy pill. Thirteen cases of breast cancer were diagnosed among the women on raloxifene; 27 cases were found among those taking the placebo.

Women taking raloxifene had a 90 percent lower risk of a type of cancer called estrogen-receptor positive breast cancer. However, raloxifene had almost no effect on estrogen-receptor negative breast cancer, one of the hardest forms of the disease to treat. It is most commonly developed by younger women and those with a genetic predisposition to the disease.

An editorial accompanying the study in today's Journal of the American Medical Association called the findings encouraging but cautioned that raloxifene cannot yet be considered suitable for most women.