Females at risk of breast cancer or dense breast tissue benefit from having additional MRI or ultrasound screening when undergoing their annual mammography, researchers reported in JAMA (Journal of the American Medical Association) this week. The authors explained that the additional screening improves breast cancer detection rates.

As background information on their report, the researchers wrote:

“Annual ultrasound screening may detect small, node-negative breast cancers that are not seen on mammography. Magnetic resonance imaging may reveal additional breast cancers missed by both mammography and ultrasound screening.”

Wendie A. Berg, M.D., Ph.D., who used to be at the American College of Radiology Imaging Network, Philadelphia, and team carried out a study to find out whether additional ultrasound or MRI (magnetic resonance imaging) scans might improve detection rates in females at risk of developing breast cancer. They gathered data on 2,809 adult females, average age 55 years, all of them at higher risk of breast cancer or dense breasts, from 21 sites. The participants agreed to undergo 3 annual independent screens with mammography and ultrasound (ordered randomly).

Below are some highlights from their report:

  • 2,662 of the participants had 7,473 mammogram plus ultrasound screenings
  • 110 of them had 111 “breast cancer events”
  • 53% (59) of the cancers were detected via mammography (not exclusively)
  • 30% (33) of the cancers were detected by just mammography
  • 29% (32) of the cancers were detected by just ultrasound
  • 8% (9) of the cancers were detected by MRI after ultrasound and mammography had failed to do so
  • 10% (11) cancers were overlooked by any type of imaging scree
  • 2.6% (16) of the 612 females in the MRI sub-study had a breast cancer diagnosis

In the second and third years combined, out of 4,814 incidence screens, 75 participants had a cancer diagnosis.

The authors reported that by adding ultrasound screening to mammography to each annual screen, detection rates improved by 5.3 cancers per 1,000 participants in the first year and 3.7 in the second and third years. An average of “4.3 per 1,000 for each of the 3 rounds of annual screening.”

Adding MRI screening to mammographies improved cancer detection with a “supplemental cancer detection yield of 14.7 per 1,000 participants”.

How many screens were required to detect one cancer?

  • 127 mammographies
  • 234 supplemental ultrasounds
  • 68 supplemental MRIs

The researchers concluded:

“Despite its higher sensitivity, the addition of screening MRI rather than ultrasound to mammography in broader populations of women at intermediate risk with dense breasts may not be appropriate, particularly when the current high false-positive rates, cost, and reduced tolerability of MRI are considered.”

Written by Christian Nordqvist