Ultrasound Better Than Mammography for Women Under 40

Breast ultrasound is superior to mammography for initial evaluation in women aged 30 to 39 and should be the primary imaging modality, according to a study in the November issue of the American Journal of Roentgenology.

Further, the use of mammography in addition to the ultrasound is not necessary. “We found that adjunct mammography adds little value to ultrasound evaluation in this clinical scenario,” wrote the study’s authors, led by Constance D. Lehman, MD, PhD, director of imaging at Seattle Cancer Care Alliance (SCCA).

Researchers from the University of Washington in Seattle and SCCA studied 954 women (1,208 cases), aged 30 to 39, who underwent breast ultrasound and mammography between January 1, 2002, and August 31, 2006, for focal breast signs or symptoms. Biopsy and/or imaging surveillance determined benign versus malignant outcomes and patients were followed for a minimum of 24 months.

Researchers found that 1,185 of the cases were benign (98.1 percent) and 23 were malignant (1.9 percent). Sensitivities for ultrasound and mammography were 95.7 percent and 60.9 percent, respectively. Specificities for ultrasound and mammography were 89.2 percent and 94.4 percent, respectively.

The ultrasounds had a 99.9 percent negative predictive value (NPV) and mammographies had 99.2 percent. Positive predictive value (PPV) was 13.2 percent for ultrasound and 18.4 percent for mammography.

“Mammography detected one additional malignancy in an asymptomatic area in a 32-year-old woman who was subsequently found to have a BRCA2 gene mutation,” the authors noted.

European guidelines typically recommend ultrasound as the primary modality in women under 40 and mammography for those over 40. The American College of Radiology’s Appropriateness Criteria calls for ultrasound as primary modality only in women who are under 30, and mammography as the primary imaging modality in those 30 and older. However, the authors concluded, the study’s findings substantiated the use of breast ultrasound as a primary imaging modality for patients in their 30s.