Why do some women with dense breasts skip supplemental MRI after a negative mammogram?

Most women with extremely dense breasts who decline the invitation to receive supplemental MRI after a negative mammogram do so because of “MRI-related inconveniences” or anxiety, according to a new study published by Clinical Radiology.

“Little is known about the willingness of women, who are selected on the basis of breast density only, to undergo a supplemental screening MRI, or about reasons for these women to accept or refuse this screening,” wrote lead author S.V. de Lange, MD, of the University Medical Center Utrecht in the Netherlands, and colleagues. “To explore a possible future implementation of this technique, it is important to know the acceptability of supplemental screening with MRI.”

The authors studied more than 8,000 women with extremely dense breasts who were invited to receive supplemental MRI after a negative mammogram as part of the Dense Tissue and Early Breast Neoplasm Screening (DENSE) trial from 2011 to 2015. All women were between the ages of 50 and 75. Reasons for participating, or not participating, were requested.

Overall, while 66 percent of the women said they were interested in the supplemental MRI, 59 percent of them participated. Out of the 41 percent of women who did not participate, more than 26 percent said the reason was “MRI-related inconveniences and/or self-reported contraindications to MRI.” This includes claustrophobia, for example, or a fear of needles. Meanwhile, 20.9 percent said they did not participate for “personal reasons” and 20.8 percent declined due to anxiety. More than 14 percent of women who did not participate said it was for “practical reasons” such as time constraints or travel-related issues.

The authors noted that this feedback can be used to improve participating in future screening programs.

“If effectiveness is proven and supplemental screening in women with extremely dense breasts is embedded in a regular screening program, this proportion could be higher,” they wrote. “As ‘anxiety regarding the result of supplemental screening’ is an important reason for non-participation, offering both techniques on the same day, delivering one combined evaluation result and providing clear and evidence-based information of benefits and harms, might further reduce barriers to participation.”

Of the women who did participate in the DENSE trial, the No. 1 reason for participating was the “expected personal health benefit.”