Annual Breast MRIs Urged For Women at Cancer Risk

By Rob Stein
Washington Post Staff Writer
Wednesday, March 28, 2007

A major medical group is recommending for the first time that women at greatest risk of breast cancer undergo MRI exams every year to try to catch more tumors at their earliest, most treatable stages.

The American Cancer Society is issuing new guidelines today that urge annual MRIs for women at high risk because of a strong family history of the disease, a genetic predisposition or other reasons. As many as 1.6 million women in the United States fall into this high-risk category.

For these women, the recommendation adds the MRI (magnetic resonance imaging) exam to the standard tools that doctors should use routinely to detect breast cancer, marking the most significant change in the society's influential screening guidelines since doctors started recommending annual mammograms. The more sensitive MRI exams can pick up small tumors that mammograms frequently miss.

"The goal here is to do a better job of finding breast cancer early, when they are much more likely to be treated successfully," said Robert A. Smith, the society's director of screening.

The guidelines stop short of recommending annual MRI breast screening for all women, saying that there is insufficient evidence to support wider use of the relatively costly exams. But they say that women at a lesser, but still elevated, risk because, for example, they are breast cancer survivors or have a family history of the disease, should consult with their doctors about undergoing regular MRIs as well.

The guidelines stress that the exams should be done in addition to annual mammograms and regular physical exams in the hope of driving down the death toll from the common, widely feared malignancy.

The new guidelines come as researchers announced that a large study found that women whose breast cancer was diagnosed by mammogram or self-exam should have their other breast scanned by MRI to search for tumors.

While many patient advocates and breast cancer experts welcomed the guidelines, others questioned whether there is enough evidence to justify the recommendation. Echoing the debate over mammography, they noted that detecting cancer early does not necessarily translate into saving lives and can subject women to unnecessary tissue biopsies and other treatment and anxiety.

"You can find a lot of cancer, but that's not the same thing as helping people live longer or better," said Russell Harris of the University of North Carolina. "It's unclear how many women really will be helped and how many will be hurt by over-diagnosis and overtreatment."

Breast cancer strikes more than 212,000 American women each year and kills more than 40,000, making it the most common cancer and second leading cause of cancer death in women, after lung cancer.

Routine mammography has helped cut the death rate, but mammograms, which are X-rays of the breast, can miss small tumors. MRI uses magnetic fields instead of radiation to create images after patients are injected with dye.

After reviewing research on MRI since 2002, a panel of experts assembled by the American Cancer Society endorsed annual MRI screening for women whose risk is about 20 percent above average for any of several reasons, including testing positive for one of the known breast cancer genes; having a close relative -- mother, sister or daughter -- who has tested positive for one of the genes; having at least two close relatives who have had breast cancer; or having had chest radiation for Hodgkin's disease.

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.