Scientists Identify Gene That May Be Link to Breast Cancer

Scientists have identified a gene that might play an early role in producing breast cancer, a finding that might lead to ways to prevent such cancers.

Scientists found that the gene was frequently overactive in early breast cancers but only rarely so in non-cancerous breast abnormalities.

If further research shows that the extra activity promotes breast cancer, drugs aimed at slowing it down may prevent some breast cancers in women who are at high risk, said researcher Dr. David Page.

The finding may also eventually lead to a test to tell whether certain microscopic breast abnormalities signal a particularly high risk of breast cancer later on, Page said. That could allow preventive treatment, he said.

The work is presented in the December issue of the journal Nature Medicine by Patricia Steeg of the National Cancer Institute, Page of the Vanderbilt University School of Medicine in Nashville, Tenn., and others.

The gene tells cells how to produce a protein called cyclin D. The protein is one of several that tell cells to produce an extra set of genetic material to be passed along when the cell divides into two. It may also have other jobs, Steeg said.

The researchers looked at an indicator of the gene’s activity in 94 breast abnormalities that had been removed in biopsies. They found that the gene had been overactive in only 18% of non-cancerous lesions.

In contrast, overactivity appeared in 76% of one kind of early breast cancer and 87% of a different early kind and 83% of samples from full-blown breast cancer.

Steeg cautioned that scientists have not yet shown whether the overactivity actually encourages breast cancer. Nor have women been followed over time to see if overactivity in certain lesions signals an elevated risk of breast cancer later, she said.

Dr. Larry Norton, chief of breast cancer medicine at the Memorial Sloan-Kettering Cancer Center in New York, said the work is among several studies that are giving clues about the origins of early breast cancer.

“It’s just beginning and we don’t have a specific therapy that’s derived from this work at this moment, but it opens up a lot of very exciting possibilities,” he said.