For dense breasts, ultrasound detects more cancers but tomo may yet be top screening option

Adjunct ultrasound has gone up against adjunct tomosynthesis and come out on top, the former beating the latter at incremental breast-cancer detection in women with dense breasts while avoiding recalls for false positives at a similar clip, according to a study published online March 9 in the Journal of Clinical Oncology.

But not so fast, ultrasound. Tomo detected more than 50 percent of breast cancers that mammography would have missed in the study cohort, prompting the authors to conclude that tomo has the potential to be considered the primary screening modality for women with dense breasts since it requires no add-on procedure.  

Alberto Tagliafico, MD, University of Genoa in Italy, and colleagues write that they detected 24 additional breast cancers, 23 of which were invasive, in 3,231 asymptomatic screening participants with dense breasts (median age, 51 years).

Ultrasound detected 23 of the 24 cancers, scoring an incremental detection rate of 7.1 per 1,000 screens (95 percent confidence interval), while tomosynthesis detected 13 (CDR, 4.0 per 1,000 screens, 95 percent confidence interval).

Incremental false-positive recall occurred in 107 participants (3.33 percent), and it did not differ to a statistically significant degree between ultrasound, tomosynthesis and biopsy.

The report is a preliminary update from the ongoing, prospective, multicenter ASTOUND study. The acronym stands for Adjunct Screening With Tomosynthesis or Ultrasound in Women With Mammography-Negative Dense Breasts.

In an accompanying opinion piece, Wendie Berg, MD, PhD, University of Pittsburgh, writes that preliminary results from ASTOUND should go a long way toward helping to inform personalized screening choices for women with dense breasts.

“Methods that improve detection of node-negative invasive cancer should benefit women; a reduction in interval cancers has been shown for screening ultrasound, and a reduction in late-stage disease and improved metastasis-free survival has been shown for MRI,” she writes. “For tomosynthesis, the benefits are likely more modest.”

“For women with dense breasts given the choice of ultrasound or tomosynthesis, ultrasound shows more cancers,” Berg adds. “Further validation of these results is critically needed, as is longer-term follow-up to compare incidence screening results for tomosynthesis and ultrasound.”

The same day the journal published the study and commentary, co-author Nehmat Houssami, University of Sydney, presented its highlights at the European Breast Cancer Conference in Amsterdam, according to a press release from the European Cancer Organization.