Women who qualify for supplemental breast screening with MR imaging may be able to skip the mammogram and go straight to MR, suggests research presented Tuesday.
Morscheid
"This is a first-of-its-kind study, and the results are intriguing because they demonstrate that MR imaging alone is sufficient for effective breast cancer screening—effective not only in terms of cancer detection but also by oncological outcome metrics such as interval cancer rate," said principal investigator Stephanie Morscheid, MD, from the departments of diagnostic and interventional radiology at University Hospital Aachen in Germany.
For women with dense breasts who undergo both mammography and MR imaging, the additional cancer detection rate attributable to mammography seems to be limited. But until this study, there haven't been definitive data on what happens when screening protocol takes mammography out of the equation.
Dr. Morscheid's team has thus far recruited 1,085 women, aged 40 to 85 years, in their ongoing prospective study. These women presented without a personal history of breast cancer and underwent abbreviated MR imaging alone—without mammography—for screening. MRI's performance was validated by either two-year follow-up or by biopsy of suspicious lesions.
The participants have undergone a total of 2,734 MRI studies, with a mean follow-up of four years for each participant. In the first screening round, 23 cancers were detected—demonstrating a cancer detection rate of 27.3 per 1000—and another 25 were found in the 1,888 subsequent exams, for an incidence cancer detection rate of 7.1 per 10000. MRI performed with a sensitivity of 93.5%. MR imaging-known cancers were occult on bilateral pre-operative 3D mammography in 66% of cases. Two additional clinically occult invasive cancers were detected by additional self-initiated ultrasound screening in two women at 8 and 23 months after the respective screening MRI, for an interval cancer rate of 0.57 per 1000.
Study Included Women at Average Risk for Cancer
"Our study cohort is not limited to women with dense breasts," Dr. Morscheid noted. "We included women at average risk for breast cancer, independent of breast density. The fairly high cancer detection rate was surprising, given that our cohort was not selected based on risk."
Women included in the study had no previous history of cancer, no atypias and no breast cancer-associated mutations.
Dr. Morscheid says that the program plans to continue recruiting and expanding the study. Meanwhile, in their ongoing study, no cancers have been found on mammography that weren't also evident on MRI.
"Our results demonstrate that women who have access to breast MRI screening can safely forego supplemental mammography," she concluded. "Performing MR screening without mammography—instead of MRI in addition to mammography—may be a more cost-effective option."
Access the presentation, "Screening Without Mammography Using Abbreviated Breast MRI Alone," (T7-SSBR07-4) on demand at Meeting.RSNA.org
