Ultrasound, MRI with Annual Mammo Effective

April 3, 2012

Adding ultrasound or MRI to annual mammography screening may benefit women at increased risk of breast cancer and dense breasts but might not be appropriate for women at intermediate risk.

Adding ultrasound or MRI to annual mammography screening for women at increased risk of breast cancer and dense breast tissue provides a higher rate of detection of incident breast cancers. However, adding this screening for women at intermediate risk may not be appropriate, according to a study published in the Journal of the American Medical Association.

Researchers from the American College of Radiology Imaging Network in Philadelphia analyzed results from 2,809 women who had an elevated breast cancer and dense breast tissue (total 7,473 screenings). After three screening rounds, 612 of the 703 women who chose to undergo an MRI had complete data. Nearly 54 percent of the women had a personal history of breast cancer.

Results showed that 59 cancers (53 percent) were detected by mammography, including 33 (30 percent) that were detected by mammography alone; 32 (29 percent) by ultrasound alone, and 9 (8 percent) by MRI only after the cancer had not been detected by either mammography or ultrasound. Eleven cancers (10 percent) were not detected at all through imaging. Among the 612 women in the subgroup, 16 cancers were diagnosed.

The added ultrasound screenings done in the second and third year provided increased cancer detection, finding cancer in 75 women. This added detection of 5.3 cancers per 1,000 women in the first year, 4.3 per 1,000 for each of the three rounds of annual screening. When MR imaging was added, there was a supplemental cancer detection yield of 14.7 per 1,000 women.

While these findings do show increased detection, the researchers cautioned about their routine use for women who are not at higher risk.

“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,” the authors wrote.