Women With Dense Breast Tissue May Benefit From Abbreviated Breast MRI

Supplemental screening for breast cancer, in the form of abbreviated breast MRI (AB-MR), may benefit some women who have dense breast tissue, according to recent research in Journal of Clinical Oncology.

For many women with dense breasts, mammography has been reported to have a 30% sensitivity rate, while the rate of interval cancers was as high as 30% among women who had a negative breast cancer screen in the previous year, the study authors noted.

The AB-MR would be in addition to the current standard-of-care mammography via digital breast tomosynthesis (DBT) and follow that procedure. For this study, it consisted of 3 sequences:

• Short-TI inversion recovery
• Precontrast T1 fat-suppressed
• One postcontrast sequence

A patient cohort of 475 asymptomatic women underwent AB-MR between January 1, 2016, and February 28, 2019, at the Hospital of the University of Pennsylvania. Most were older women aged 50 to 59 years (35.2%) or 60 to 69 years (28.0%), with a mean (SD) age of 58 (range, 32-83) years, and had heterogeneously dense breasts (70.5%). Sixteen had history of breast cancer.

The overall results from the retrospective analysis grouped the women into 3 categories, based on what AB-MR found, which was identified in their electronic medical records:

• Benign/negative exam: 88.4% (n = 420)
• Follow-up recommended: 2.7% (n = 13)
• Biopsy recommended: 8.8% (n = 42)

There was a mean and median of 90 and 59 (range, 0-333) days, respectively, between DBT and AB-MR. Most (62.7%) women had DBT more than 90 days before the AB-MR, while few (5.9%) had at least 270 days between procedures.

Of the 42 women recommended to undergo biopsy, 39 (92.8%) had that procedure, and malignancies were found in 12 (30.8%), both invasive carcinomas (n = 7) and ductal carcinoma in situ (n = 5). At a 6-month follow-up, invasive ductal carcinoma was found in a 13th patient. In total, 14 cancers were found, with one of the women having bilateral disease.

These results equate to a cancer detection rate of 27.4 per 1000 (n = 13; 95% CI, 16.1-46.3).

In addition, among the women with invasive carcinomas, their mean tumor size was 0.5 cm, with a range from 0.6 to 1.0 cm. Among these women, too, none had positive nodes.

No interval cancers were found at a 1-year follow-up for the 13 women with malignancies, for a AB-MR sensitivity of 100% (95% CI, 77.2%-100%) and specificity of 90.9% (87.9%-93.2%).

The women were categorized as having heterogeneously or extremely dense breasts according to American College of Radiology BI-RADS, 5th edition, and a negative (BI-RADS 1 or 2) mammogram finding in the previous 11 months.

“Our preliminary results from supplemental AB-MR screening in women with dense breasts demonstrates an increase in cancer detection over DBT screening with [positive predictive values] that are in keeping with well-established benchmarks,” the authors concluded. “Certainly, more data from additional sites with diverse screening populations and readers is needed to determine the reproducibility of our single-institution results.”

Because this was a single-institution study and the patients could decide, or not decide, to enroll, the authors caution on possible bias within their results, as well as lack of generalizability. Self-reported risk of breast cancer and lack of family history and biopsy results were other limitations.

Reference

Weinstein SP, Korhonen K, Cirelli C, et al. Abbreviated breast magnetic resonance imaging for supplemental screening of women with dense breasts and average risk. J Clin Oncol. Published online September 15, 2020. doi:10.1200/JCO.19.02198