Breast MRI May Up Biopsy, Cancer-Detection Rates in Women With Breast-Cancer History

By Will Boggs MD

June 07, 2019

NEW YORK (Reuters Health) - Compared with surveillance mammography, breast MRI results in higher biopsy rates and higher cancer-detection rates in women with a personal history of breast cancer, suggests an observational study.

"Women should continue to get annual mammography as the first best test to find second breast cancers," Dr. Karen J. Wernli from Kaiser Permanente Washington Health Research Institute, in Seattle, told Reuters Health by email. "For most women, there is no choice, as her doctor is likely not recommending breast MRI, given no widespread recommendations for breast MRI in this population."

A small but growing proportion of women who have had breast cancer undergo breast MRI as an adjunct to surveillance mammography, but there is limited evidence on the benefits and harms of breast MRI in these women.

To compare the performance of breast MRI with mammography alone, Dr. Wernli and colleagues used data from more than 13,000 women with previous breast cancer who underwent nearly 34,000 surveillance mammographic examinations and 2,506 surveillance breast MRI examinations at community-based Breast Cancer Surveillance Consortium radiology facilities.

In unadjusted analyses, cancer detection rates per 1,000 examinations were higher with breast MRI (10.8) than with mammography (8.2), as were biopsy rates (10.1% vs. 4.0%).

After adjustment for other factors, the odds of cancer detection were 70% greater with breast MRI than with mammography (P=0.03), and the odds of having a biopsy were 2.2-fold greater with breast MRI than with mammography (P<0.001), the researchers report in Radiology, online June 4.

Biopsy rates after breast MRI were higher than after mammography both at first examinations (11.9% vs. 5.2%) and at subsequent examinations (7.3% vs. 3.3%).

In contrast, sensitivity rates and interval cancer rates did not differ significantly between women who had breast MRI and those who had mammography.

"Physicians should continue to reemphasize surveillance mammography for women with personal history of breast cancer and to be certain their patients continue with mammography," Dr. Wernli said. "For some women in whom breast MRI might be recommended, they should remember that the breast MRI can result in more biopsies and keep this in mind when considering additional imaging."

Dr. Mary S. Newell from Emory University, in Atlanta, who wrote a linked editorial, told Reuters Health by email, "Each woman should weigh the benefit of having her cancer detected earlier than would have occurred with just mammography (and thereby increasing the chance of cure and less aggressive treatment) versus the possibility that by having an MRI, the likelihood of needing a needle biopsy may increase, and decide which is more important to her."

"We need to do even more research like the authors did here to figure out how best to use our exciting breast imaging tools to find cancers as early as we can, and work to further decrease the side effects of imaging exams, such as biopsies that end up being benign," she said.

"I would hope that physicians (and patients) probe farther when they see a study or an organization making a conclusion about whether the risks outweigh the benefits of any given exam, including screening mammography and use of MRI to find breast cancers," Dr. Newell said. "We need to make sure we all understand the magnitude and implication of the benefits that we are weighing against risks before we can determine if they are, in fact, being fairly compared."

"Women can decide what is the right path for them. However, we must ensure that women have continued access to screening, so that the choice is theirs, not one made for them under the guise of acting in their best interest!" she said.


Radiology 2019.