Allison Gandey

June 28, 2007

June 28, 2007 (Chicago) — Deliberations over breast cancer screening are back in the news again after German researchers at the American Society of Clinical Oncology 43rd Annual Meeting presented data in favor of magnetic resonance imaging (MRI). "MRI has been in the news a lot lately," moderator Julie Gralow, MD, from the University of Washington in Seattle, said during a press briefing. "A lot of women are asking us, should I be getting an MRI?"

New American Cancer Society screening guidelines recommend MRI for women at the highest risk for breast cancer. And data published in a recent New England Journal of Medicine paper seemed to stack up in favor of MRI, suggesting that screening at the time of diagnosis of 1 breast cancer can lead to finding a second breast cancer (Lehman CD et al. New Engl J Med 2007;356:1295-1303.)

But not everyone has been as enthusiastic about breast MRI. The latest National Comprehensive Cancer Network (NCCN) guidelines caution against relying too heavily on MRI and using laboratory testing as the sole determinant for therapy. Presenting at the group's annual meeting in March and reported at the time by Medscape, Beryl McCormick, MD, from the Memorial Sloan-Kettering Cancer Center, in New York, spoke of the challenges of MRI screening.

"Unfortunately, not all breast MRIs are created equal," Dr. McCormick said. "We are seeing an increasing number of newly diagnosed breast cancer cases at Memorial who come in with MRIs performed outside. Most are not of use to us, and a radiologist won't even read them," she said. "We want to emphasize that MRI is an adjunct to other breast imaging and should not be used in place of standard breast imaging with mammography and ultrasound," Dr. McCormick suggested. "There's no population-based screening information on the use of MRI; it's not for that."

Lack of Standardization in MRI a Key Barrier

Dr. Gralow agreed that standardization in breast MRI has been a problem. "It's a great tool in the right hands, but we don't yet have the quality control as we do for screening mammography. We hope soon to have at least a partial rectification of this," she said. The American College of Radiology is currently putting together a voluntary accreditation program and, within the next year or so, is planning to initiate standards at a number of centers. "I think it would be fair to say that programs that take this are at least attempting to create a standard with reproducible results," Dr. Gralow said.

At the NCCN meeting, Dr. McCormick said that MRI could be helpful in evaluating the extent of biopsy-proven invasive lobular cancer, which can be difficult to define on mammogram and ultrasound. And in cases where recurrence is suspected and the mammogram is inconclusive, an MRI may help.

But in Germany, MRI screening is reaching new heights. Highly standardized and more widely accepted, Dr. Gralow says it is not surprising that researchers there have been able to present such a compelling case in favor of MRI. Mammography highlights calcifications around ductal carcinoma in situ, while MRI detects areas of increased vascularization, a process more commonly found around high-grade carcinomas.

During a news conference presenting the findings, lead investigator Christiane Kuhl, MD, from the University of Bonn, in Germany, pointed out that with growing concern about overdiagnosis and unnecessary treatments in women with lesions that may never progress to cancer, MRI offers interesting potential.

Dr. Gralow agreed. Speaking to reporters, she concurred that MRI may help physicians distinguish between patient groups and help identify who should be treated.

In this prospective study, more than 5000 consecutive women were referred to a dedicated breast unit for screening or for diagnostic assessment. Patients had bilateral mammography with at least 2 views plus spot-compression views where appropriate and a high-resolution bilateral MRI.

Sensitivity for Ductal Carcinoma in Situ
Ductal Carcinoma in Situ
Mammography, n (%)
MRI, n (%)
Positive (n=167)
93 (56)
153 (92)

Sensitivity by Ductal Carcinoma in-Situ Grading
Ductal Carcinoma in Situ
Mammography (%)
MRI (%)
Non–high grade
61
85
High grade
52
98

"MRI is much more sensitive than mammography for diagnosing ductal carcinoma in general and aggressive carcinoma in particular," Dr. Kuhl told reporters. "MRI doubled the sensitivity for ductal carcinoma overall," she said, and "half of high-grade ductal carcinomas in situ were diagnosed only by MRI."

American Society of Clinical Oncology 43rd Annual Meeting: Abstract 4000. Presented June 5, 2007.

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