Digital mammography better for screening dense breasts

For screening dense breasts, 3D digital mammography outperforms standard 2D mammography, according to results of a prospective trial of more than 25,000 women. The findings were presented at the Radiological Society of North America (RSNA) in an abstract by researchers from Hologic.

In the trial, 25,547 women ages 50 to 69 were screened prospectively with full-field digital mammography (FFDM or 2D) alone or FFDM plus digital breast tomosynthesis (3D). Eight radiologists used a 5-point rating scale for probability of cancer to interpret the results from the two study arms. Before a decision was made about whether to recall a woman for diagnostic workup, an arbitration meeting was held to review each case that received a positive score from at least one radiologist.

At the arbitration meetings, case-based 81-RADS density scores were recorded. The American College of Radiology’s Breast Imaging-Reporting and Data System or BI-RADS, rates breast density on a scale of 1 to 4, from least to most dense. Cancers detected in the two study arms were stratified by breast density according to BI-RADS score.

Legally speaking: Two cancer deaths, two jury decisions

With FFDM plus 3D mammography, 80% of 132 cancers in women with dense breasts were detected, compared with only 59% with FFDM alone. Of the 257 malignancies detected with FFDM alone and with FFDM plus 3D mammography, 105 were BI-RADS density 2, 110 were density BI-RADS density 3, and 22 were BI-RADS density 4. The addition of tomosynthesis to FFDM improved the cancer detection rate from 68% (85/125 to 84% (105/125) (P<0.05) in women with BI-RADS density 3 or 4 breasts.

The researchers concluded that adding tomosynthesis has potential to significantly increase cancer detection in women with breast density BI-RADS 2-4, but no improvement was seen in those with BI-RADS density 1.

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