The National Comprehensive Cancer Network (NCCN) recommends annual breast MRI for women who have or are likely to have a BRCA mutation. But is annual MRI screening plausible, practical or necessary for all women at high risk for breast cancer? At the 2024 annual meeting of the American Society of Breast Surgeons, experts delved into the nuances of this topic during a debate session on controversial issues.
Pro
Arguing the pro side of annual MRI as a critical component of screening in high-risk patients, Patrick Borgen, MD, the chairman of the Department of Surgery at Maimonides Health and a professor of surgery at SUNY Downstate Health Sciences University, in Brooklyn, N.Y., said mammography alone has limitations, especially in high-risk patients.
“We showed early in the BRCA story that mammograms were poor in BRCA1 carriers, with false-negative rates of about 40% [J Clin Oncol 2002;20(5):1260-1268]. Mammograms have gotten better since this study, but relying on mammograms is not a great thing to do,” Dr. Borgen said.
Mammography is also less likely to detect interval cancers, which tend to grow faster and have a worse prognosis. “The paradox is that the faster a breast cancer grows and the more aggressive it is, the more likely it is for mammogram to miss it.”
A number of studies have shown MRI far exceeds mammography for detecting cancer in high-risk patients, having a much higher sensitivity and doubling or more than doubling the cancers found per 1,000 patients. Further, about half the cancers found on MRI are small (<10 mm).
“And here’s another important theme: A Netherlands trial randomized average-risk women with extremely dense breasts to MRI or no MRI. In the MRI group, interval cancers disappeared; this led the Netherlands to approve MRI for average-risk women with very dense breast tissue,” Dr. Borgen said (N Engl J Med 2019;381[22]:2091-2102).
He acknowledged the association between MRI and mastectomy rates. “But here’s the catch: We did a lot of risk-reducing mastectomies in the 1990s when BRCA1/2 were published, with mammograms being wrong 40% of the time. MRI gives us and our patients the confidence to forgo these radical operations.”
Ultimately, in high-risk patients, MRI results in a higher detection rate of smaller and mostly node-negative cancers, has a positive impact on postsurgical treatment and decreases interval cancers, Dr. Borgen said.
And it certainly served Olivia Munn. After the actress had a normal mammogram and tested negative for genetic mutations, her surgeon did a risk calculation and found Ms. Munn’s risk to be 37%.
“On screening MRI, she had bilateral luminal B breast cancers,” Dr. Borgen said. Ms. Munn underwent bilateral mastectomy with immediate reconstruction. “MRI sort of saved the day.”
Con
Arguing the con side of the debate, Carla Fisher, MD, MBA, an associate professor of surgery and division chief of breast surgery at Indiana University School of Medicine, in Indianapolis, acknowledged that annual MRI in high-risk patients is what breast surgeons teach their residents and fellows, as per NCCN guidelines. “This is a tough one to argue. But the devil is in the details,” she said.
To start, many components go into defining a patient as high risk: genetic mutations, breast density, menstrual history, lifestyle factors, a history of atypia or lobular carcinoma in situ (LCIS), family history. But is the patient with a 20% lifetime risk of developing breast cancer the same as one with an 80% risk? “Should we be screening them the same? I would argue no,” Dr. Fisher said.
Particularly in patients with LCIS or a history of atypia, research finding MRI not associated with earlier stage, smaller size or node negativity in these patients challenges the concept of annual MRI screening, she said. “For these patients, risk-reducing chemotherapy is recommended. In our high-risk clinic, most of these patients are not routinely getting breast MRI.”
There are also questions about the cost-effectiveness of MRI—the balance between a test or intervention and its benefits for the patient. Despite the increasing cost of MRI and the escalation of high-deductible insurance plans, annual MRI would likely be considered cost-effective and warranted in patients at the highest ends of the high-risk spectrum, Dr. Fisher said.
“But if you compare those patients to the ones with the 20% lifetime risk, maybe it is not cost-effective.”
But it could be if the interval between exams exceeds a year. One study of MRI screening in women with increased risk but without a known BRCA1/2 or TP53 variant found that to be the case (JAMA Oncol 2020;6[9]:1381-1389). “It was a Dutch study, so their threshold for cost-effectiveness was different, but they concluded that MRI screening every 18 months was cost-effective,” Dr. Fisher said.
Although MRI may be the most sensitive screening modality, there are other options, including tomosynthesis, ultrasound, contrast-enhanced mammography and abbreviated MRI, Dr. Fisher said. “Abbreviated MRI, in particular, is quicker, cheaper, more efficient and effective for high-risk patients.”
She acknowledged that there are some reimbursement issues with abbreviated MRI, which her institution offers to patients with dense breasts at an out-of-pocket cost of $250.00. Many patients choose this option as a less expensive alternative to standard MRI.
“I contend that MRI may be a component of some high-risk protocols, but it’s not critical annually for all high-risk patients,” Dr. Fisher concluded.
A Continuing Controversy
Kay Yoon-Flannery, DO, a co-director and breast surgeon of the Janet Knowles Cancer Center, MD Anderson Cancer Center at Cooper, in Camden, N.J., told General Surgery News that the use of MRI in high-risk patients remains controversial due to the modality’s expense, high rate of false positives, varying sensitivity and inconvenience to patients.
“Having said that, our job is to counsel patients, and we need to consider MRI from the patient’s perspective. For some patients, the higher sensitivity may be what they’re looking for, even if it leads to more biopsies. But for others, the abnormal findings that lead to biopsies that don’t find malignancies—that anxiety level may be something they just can’t deal with,” Dr. Yoon-Flannery said.
“For patients with a BRCA mutation, screening with MRI is definitely beneficial, and that wasn’t debated from either perspective. But apart from those high-risk patients, it hasn’t been linked to further detection of cancer. So, in the breast world, use of MRI is controversial, and I think it will continue to be.”
This article is from the October 2024 print issue.
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