A multicenter American College of Radiology Imaging Network trial has determined that breast lesions categorized as BI-RADS 3 or probably benign have low malignancy rates, suggesting that follow-up imaging intervals should be extended from six months to one year.
In the study, the results of which were published in Radiology, a team of researchers led by Richard Barr, M.D., a professor of radiology at the Northeast Ohio Medical University, analyzed data from a trial in which both annual mammography and ultrasound screenings were performed on more than 2,600 women with dense breasts at 21 sites around the country.
The researchers wanted to analyze the trial's ultrasound-detected lesions assessed as BI-RADS 3, Barr said in an announcement, because they are "common on screening ultrasound and often lead to unnecessary biopsies and additional imaging, causing substantial cost and anxiety for patients."
Of the 2,662 women in the trial, 519 had a total of 745 BI-RADS 3 lesions, only six of which were malignant (a total malignancy rate of 0.8 percent).
Guidelines suggest BI-RADS 3 lesions be evaluated for suspicious changes at six-, 12-, and 24-month intervals. In this study researchers found suspicious changes in one BI-RADS 3 lesion at the six-month interval, as well as a second BI-RADS 3 lesion at 12 months.
"As a result of the low malignancy rate of BI-RADS 3 lesions and the low rate of suspicious changes at six-month follow-up imaging, yearly follow-up for these lesions may be appropriate," Barr said. "The cancers detected due to changes at one year had not spread beyond the breast, with similar prognosis if the lesion was biopsied on initial detection."