Women under 50 found not helped by cancer test

January 11, 1995|By Diana K. Sugg | Diana K. Sugg,Sun Staff Writer The Boston Globe contributed to this article.

Researchers who analyzed more than a dozen breast cancer studies have concluded that use of routine mammograms to screen women under 50 won't lower their risk of dying from breast cancer.

A second group of researchers specifically recommended that only women between the ages of 50 and 74 be routinely given breast X-rays.

Published in today's issue of the Journal of the American Medical Association, the articles are the latest round in the debate over whether women between ages 40 and 49 -- with no symptoms or family history of breast cancer -- should have a mammogram.

In 1993, the National Cancer Institute said that women under 50 didn't need routine mammograms unless they were at high risk. But the American Medical Association kept its guidelines, which call for breast X-rays every one to two years for women in their 40s.

In the newly published research, one group of scientists examined 13 studies conducted from 1966 to 1993, hoping an overview might shed more light on the question. They found that, statistically, mammograms didn't lower the death rate for women under age 50.

And there can be a downside to having a mammogram, said one of the study's authors, Dr. Karla Kerlikowske of the Department of Epidemiology and Biostatistics at the University of California, San Francisco. Over a 10-year period, a woman in her 40s who has an annual mammogram faces a 25 percent chance of an abnormal test, a 24 percent chance of a false positive and a 6 percent chance of a biopsy.

Yet Dr. Kerlikowske said only one in 70 women will be diagnosed with breast cancer over that same decade, compared to one in 30 women in the 50 to 60 age group.

Radiologists, patients and representatives of the American Cancer Society strongly disagreed with the findings because they believe mammograms save lives in the under-50 age group. The society yesterday called on the Cancer Institute to once again recommend routine screening for women in their 40s.

New figures released yesterday by the Cancer Institute show that breast cancer death rates among American women appear to be declining by as much as 8 percent to 9 percent in some categories. Dr. Samuel Broder, the outgoing chief of the institute, attributed the drop to mammograms in general and to advances in treatment.

But institute officials said while the benefits of screening for women over 50 are clear, it is still not clear whether screening under age 50 makes a difference. The conflict underscores the struggle in medicine over costs and benefits -- and where a person fits into statistics.

With pressure to reduce costs, physicians and insurance companies are struggling with that same question in many areas, including Down syndrome screening for older pregnant women and testing newborn babies for rare diseases.

Often left in doubt are patients like Peg Nelson. She had no risk factors for breast cancer, but felt she should have mammograms every year in her 40s.

When she was 48, the mammogram was abnormal. A few tests later, she was told she had breast cancer. "It was just very quietly beginning," said the Bel Air woman, who believes the mammogram saved her life.

According to American Cancer Society estimates for 1995, about 33,800 cases of breast cancer -- 18 percent of all cases -- will be diagnosed among women in their 40s in the United States.

But the biology of tumors is often more aggressive in younger women, and because their breast tissue is denser, it's more difficult to detect tumors through mammograms, Dr. Kerlikowske said. If a woman age 45 finds a breast tumor, her risk of dying could very well be the same if she finds out immediately or later.

Dr. Kay Dickersin, a breast cancer survivor who is an assistant professor in the Department of Epidemiology and Preventive Medicine at the University of Maryland School of Medicine, said the effectiveness of mammograms in women age 40 to 49 would have become apparent if it were significant.

"We probably have sufficient data to know that even if mammography is effective in younger women, it still isn't a very good method of detection," she said. Money for mammogram research might be more wisely spent seeking other methods of breast cancer detection for women in their 40s, she said.

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