Cancer detection rate with ultrasound (US) is comparable with mammography, with a greater proportion of invasive and node-negative cancers among US detections, according to a study of 2,662 participants who completed 3 annual screens and had biopsy or 12-month follow-up. Researchers found:

• 110 women had 111 breast cancer events: 80.2% invasive cancer, median size 12 mm.

• Number of screens to detect 1 cancer was 129 for US and 127 for mammography.

• Cancer detection was comparable for each of US and mammography at 58 of 111, with US-detected cancers more likely invasive.

• Invasive cancers detected by US were more frequently node-negative, 34 of 53, vs 18 of 41 for mammography.

• For 4,814 incidence screens, recall rates were 10.7% for US and 9.4% for mammography, biopsy rates were 5.5% for US and 2.0% for mammography, and positive predictive value of biopsy was 11.7% for US and 38.1% for mammography.

Citation: Berg WA, Bandos AI, Mendelson EB, Lehrer D, Jong RA, Pisano ED. Ultrasound as the primary screening test for breast cancer: analysis from ACRIN 6666. J Natl Cancer Inst. 108(4):djv367. doi: 10.1093/jnci/djv367.