Screening MRI for Breast Cancer: Should YOU Get One?

Patient Expert

Two news stories about breast MRI hit the airwaves simultaneously yesterday, and together they signal a sea change in how certain women should be screened for breast cancer.

Until now, mammography has been the screening method of choice for women who've reached the age where screening is desired, or have other breast cancer risk factors. Although the American Cancer Society no longer recommends monthly self-exams, every woman should know what her "normal" breasts feel like, so that she'll be aware of any changes. And women over 40 have long been advised to get regular mammograms. Now, the American Cancer Society has issued new guidelines calling for women in certain risk groups to be screened via MRI (magnetic resonance imaging), as well as mammography. At the same time, the New England Journal of Medicine, in its March 29 issue, details a national study whose results indicate that women who've been diagnosed with cancer in one breast should have an MRI in the other, as MRI can detect very early cancers that can't be seen on a mammogram.

"Prevention is clearly the preferable strategy for controlling cancer," noted the American Cancer Society's Robert A. Smith, director of cancer screening. "For the foreseeable future, the control of breast cancer will depend mostly on early detection, careful diagnostic evaluation and therapy," he said. In other words-while we're waiting for that all-too-elusive cure, our best bet is to find and treat cancer early. And according the ACS and the New England Journal of Medicine, that means using a screening device that's more sensitive than mammography: MRI, which is able to pick up very tiny tumors that can't be felt in a physical exam, or seen on a mammogram.

But before you call your doctor to switch your mammogram appointment to an MRI screening-hold on. These new guidelines don't apply to all of us. The guidelines specifically cite women 30 and older with a mutation in the BRCA1 or BRCA2 genes; women who received radiation therapy for Hodgkins' disease between the ages of 12 and 18; and women with a strong family history of breast cancer, including two or more close relatives with breast or ovarian cancer, or a close relative who developed breast cancer before the age of 50.

In addition, the NEJM article cites a National Cancer Institute study at the University of Washington Medical Center that tracked nearly 1000 women diagnosed with cancer in one breast, but not the other. When these women had a screening MRI in the unaffected breast, 121 were identified as having possible tumors. Of those, 30 had cancerous tumors, tumors that weren't discovered via mammogram. And 18 of those women had invasive cancer.

On the flip side, 91 of those women identified with possible tumors did NOT have tumors, and had to undergo the pain and expense of biopsy. These "false positives" have always been a problem with MRI screening for breast cancer, and a sticking point preventing more women at risk from having a regular MRI. In addition, the MRI procedure can cost more than 10 times what a mammogram costs; not all insurance plans cover it; it takes longer, and it can be more uncomfortable, any of which can be considerations for some women.

So, do YOU need a screening MRI? If you fall into any of the ACS guidelines, probably. If you don't meet the ACS criteria but have had cancer in one breast, maybe.

Bottom line: When it's time to call your doctor to schedule your next mammogram appointment, cite the ACS' new guidelines, as well as the National Cancer Institute study, and at least ask the question: Should I get an MRI?

Click to watch a video on breast MRI.