A study published on the JAMA Network Open on August 18, 2021, found that in Japanese women undergoing routine breast cancer screening, ultrasonography supplemental to mammography helped reduce interval cancer rates and the rate of late-stage disease. Consequently, it helped reduce breast cancer-related mortality. A secondary analysis determined that women’s breast density did not change these results.

The authors reviewed peer-reviewed studies of women whose cancers were detected by supplemental imaging using breast ultrasound or magnetic resonance imaging (MRI) that detected additional cancers in women across all density categories. Those findings, the researchers believe, suggest that with mammographic screening, underdiagnosis of breast cancer (defined as failure to detect relevant breast cancer early enough) occurs not only in women with dense breasts but also in those with non-dense tissue.

In an accompanying opinion column to the JAMA article ["A Call for Improved Breast Cancer Screening Strategies, Not Only for Women With Dense Breasts"], Christiane K. Kuhl, MD, PhD, of University Hospital in Aachen, Germany, wrote that this research suggests that there is a substantial clinical need to improve breast cancer screening in general, not only for women with dense breasts. All women – not just those with dense breasts – are "underserved by mammographic screening alone."

The debate about broadening the scope of breast cancer screening to include not only mammography but also breast ultrasound will be a vitally important policy discussion. Such a change in payment policy would be an uphill climb. The current Medicare payment policy covers only screening mammography, but does allow payment for breast ultrasound studies if ordered by the patient's treating physician.

Nevertheless, if supplemental breast ultrasound can help detect more early and invasive cancers – and if it can do so not only for women who are high risk or who have high density breast tissue – should it be considered a necessary routine adjunct test to accompany breast screening tests for all women?