MRIs Better For Detecting Breast Cancer

MRI scans beat mammograms for finding tumors in women at high risk of breast cancer, but at a far greater cost and chance of unneeded biopsies, new research suggests.

Those drawbacks make MRIs unsuitable for screening average-risk women, who are still advised to get regular mammograms starting at age 50. But the benefit of better detection from MRI, or magnetic resonance imaging, makes it worthwhile for women with faulty genes or a strong family history of breast cancer, like a mother or sister who had the disease.

``Women who are at high risk should consider getting MRI besides mammography,'' said Dr. Stephen Feig, a radiology professor at Mount Sinai School of Medicine in New York and past president of the Society of Breast Imaging. He had no role in the new research, which was done by doctors at six cancer centers throughout the Netherlands and was partly funded by the Dutch Health Insurance Council. Results were reported in Thursday's New England Journal of Medicine.

In the study, MRIs caught nearly twice as many tumors as mammograms did in women at high risk of breast cancer. For them, the value of screening is not as much of an issue as it has been in recent years for women at average risk.

An MRI scan costs $700 to $1,000 - about 10 times the cost of a mammogram. Some large insurers already cover MRIs for women at high risk. Women were screened three ways: a breast exam by a doctor every six months, annual mammograms and annual MRI scans.

However, the scans also give more false alarms. MRI's led to twice as many unneeded additional examinations as did mammography (420 vs. 207) and three times as many unneeded biopsies (24 vs. 7). Both kinds of screening did find cancers early.

Women must be counseled carefully about whether to try intensive screening instead of having their breasts or ovaries removed. If women do get an MRI, they should time it for midway through their menstrual cycles when results are best, and they should go to centers capable of performing MRI-guided biopsies if a scan shows something that needs follow-up. Breast cancer is the most common cancer in American women after skin cancer. About 216,000 new cases will be diagnosed this year, and it will cause about 40,000 deaths.