Annual Breast MRIs Urged For Women at Cancer Risk

For those women, MRIs plus mammography can double the number of cancers found, the panel said, detecting them in 6 percent of high-risk women screened, compared with about 3 percent for mammograms alone.

The panel stressed that the exam should be conducted at experienced centers that are equipped to perform follow-up biopsies.

MRI tends to produce false positives at about twice the rate of mammography, forcing more women to undergo repeated tests and sometimes biopsies and subjecting them to anxiety, distress and discomfort. But the panel concluded that the benefits outweigh the downside for those at high risk.

"In a population of women who are at significantly high risk, there is a high priority on finding breast cancer," Smith said. "They are willing to put up with more."

While MRIs are expensive -- $800 to $2,000 -- the studies indicate that the exams are cost-effective for this high-risk group, the panel found. No one has estimated what the overall cost to the nation would be if the recommendations were fully implemented, or how many insurance companies would pay for the exams, Smith said.

For women at a lower risk, the cost-benefit equation becomes less clear, the panel concluded. There is no reason at this point to recommend MRI for women who have no reason to believe they are at increased risk. Women who may be at increased risk for other reasons, including having survived breast cancer or having a family history in fewer or more distant relatives, fall somewhere in the middle, with insufficient evidence to recommend for or against annual MRIs.

Women who should seriously consider routine MRIs are those whose cancer was diagnosed in one breast by mammograms or physical exams, experts said yesterday.

The New England Journal of Medicine moved up by one day the release of the first large study to evaluate MRIs in such women. The study of 969 women in 25 centers found that MRIs detected 30 tumors that had been missed earlier, effectively doubling the number of cancers detected.

"MRI without question can identify cancer that is invisible to the mammogram," said Constance Lehman of the University of Washington in Seattle, who led the study.

In addition to allowing women to treat more tumors earlier, MRI can also reassure women that their other breast is cancer-free, enabling them to avoid a double mastectomy, an agonizing choice some women make just to be safe.

"This will give women some peace of mind," Lehman said.