MEDICINE / BREAST CANCER : Study Finds Higher Risk in One Type of Benign Disease

While most women with a condition commonly known as lumpy breasts are no more likely than others to develop breast cancer, a small percentage with one particular form of benign breast disease face nearly four times the normal risk, a new study has found.

The study, headed by a researcher at USC School of Medicine, found that women with a form of benign breast disease called atypical hyperplasia are 3.7 times more likely than women in general to develop what has become the most common cancer in women.

Atypical hyperplasia involves an unnatural proliferation of cells in the breast along with the appearance of some abnormal cells. It can be diagnosed through a biopsy after a woman or her physician identifies an abnormality through examination or mammography.

By contrast, the researchers found that women with so-called plain proliferation, without abnormal cells, faced only about 1 1/2 times the normal risk of developing breast cancer. Women with so-called non-proliferative benign breast disease faced no increased risk.

Experts said the findings should reassure women who have received a diagnosis of non-proliferative disease, and should prompt women with plain proliferation and atypical hyperplasia to be sure to have annual mammograms and regular examinations.

It is not known how many women in the United States suffer from benign breast disease--a condition that can cause a painful lumpiness in the breast and that some physicians have included under the general heading of fibrocystic breast disease.

But a half a million breast biopsies are done every year in this country, more than 80% of which prove the lump to be benign. Breast cancer now affects one in every nine U.S. women, claiming 46,000 lives every year.

Researchers have known that benign breast disease appeared to heighten breast cancer risk, said Dr. Stephanie London, lead author of the new study. But it appeared that different types of the disease carried different degrees of risk.

In the study, London and co-researchers at Harvard University compared 121 women with breast cancer who had an earlier biopsy for benign breast disease to 488 who had also had biopsies for benign breast disease but had not developed cancer.

The researchers found that the risk was highest for women whose earlier biopsies had turned up atypical hyperplasia, particularly before menopause. It was lower for those with plain proliferative disease and lowest for those without any proliferation.

“This allows you to know whether your biopsy is something to worry about or not,” said London, an assistant professor of preventive medicine. She said those with atypical hyperplasia should be especially sure to have yearly mammograms and to do self-examination.

London’s findings confirm those of an earlier study co-authored by William D. Dupont of Vanderbilt University School of Medicine, who found that women with atypical hyperplasia faced four to five times the normal risk of developing breast cancer.

Dupont said Tuesday that after those initial findings, the U.S. National Cancer Institute funded several studies--London’s among them--aimed at exploring whether the findings could be reproduced.