MRI Scans and Mastectomies
Posted by medconsumers on September 1, 2008
Preoperative MRI Linked to Increase in Mastectomies at Mayo Clinic
Magnetic resonance imaging, or MRI, made news last spring at a meeting of cancer doctors when a Mayo Clinic oncologist reported that the use of this diagnostic technology appears to increase the number of women who are choosing mastectomy over breast-conserving surgery. The finding is based on a study of early-stage breast cancer patients treated at the Mayo Clinic in Rochester, MN.
The rate of mastectomy in the U.S. had been declining steadily since the mid-1980s when a landmark national trial proved it to be no more lifesaving than breast-conserving surgery. For example, 36% of the women treated at the Mayo Clinic had a mastectomy in 2002, down from 45% in 1997.
Matthew Goetz, MD, the medical oncologist who presented these findings at the meeting of the American Society of Clinical Oncologist, called attention to the change that began to occur once preoperative MRI was introduced. The rate of women given this imaging procedure preoperatively went from 11% to 22% between 2003 and 2006. During the same period, the mastectomy rate rose from 30% to 43%.
MRI is sometimes recommended in addition to a mammogram, especially for women with dense breasts and/or a genetic predisposition to breast cancer. The newer technology has several advantages over mammography, such as no radiation exposure, no compression of the breast, and a sharper imaging that identifies more abnormalities. The downsides of MRI include high cost and sharp imaging that causes a high rate of false alarms (19% in first year and 9% in the second, according to one study).
The Mayo Clinic findings do not prove that MRI directly caused the increase in the number of women choosing mastectomy. Nor were women or doctors asked about their decision-making process. Referring to MRI’s ability to find tiny lesions that may or may not be cancer, Dr. Goetz said, “What we don’t know from this study is whether the higher rate of mastectomy observed in our patients undergoing MRI leads to greater anxiety for the patient and physician, thus leading patients and physicians to choose mastectomy over lumpectomy.”
In a recent issue of the Journal of the National Cancer Institute, Dr. Goetz elaborated on this theme, “I wonder whether patients reach a threshold where they are unwilling to deal with the uncertainty of future imaging and biopsies,” he said. “They are tired of a physician saying, ‘We’re not sure, follow up in six months with a repeat test,’ and so those patients may say, ‘Thank you very much, but let’s just proceed with a mastectomy.’”
For More Information About MRI and Other Cancer Tests:
Go to www.cancer.gov, the Web site of the U.S. National Cancer Institute (type: MRI in the search box at the top of home page).
This Web site is also a good source of information about all cancers and their respective ltreatment options by stage. There is a patient’s version for each cancer, which is billed as “less technical,” but it only describes the treatments options. To find out how good the supporting scientific evidence is for these treatment options, go to the “health professional” version. You can click into the abstracts of the clinical trials that produced the supporting evidence. The health professional version also ranks the quality or strength of the evidence. Or, call 1(800) 4-CANCER.
Maryann Napoli, Center for Medical Consumers ©