The American College of Radiology Imaging Network's biostatistics center at Brown University conducted the study and said there is a significant trade-off with ultrasound screening.

"The medical community may well decide that the screening benefit is offset by the increase in risk to women from a false positive finding," said Associate Professor Jeffrey Blume. "However this study also shows supplemental ultrasound may be beneficial in women at high risk of breast cancer who could not, or would not, otherwise undergo a magnetic resonance imaging scan. Women should consult their doctor for more information."

He noted that the combination of mammography and ultrasound, screening still missed one of every five cancers. "So the trial shows that ultrasound is not a silver bullet for breast cancer screening," he said.

The findings are detailed in the Journal of the American Medical Association.