• Posted December 4, 2025

Should You Know Whether You Have Dense Breasts? Maybe Not, Experts Argue

American women are notified if a mammogram reveals they have dense breasts, which can hamper the accuracy of breast cancer screening.

But this knowledge might be more trouble than it’s worth, a new study argues.

The news can spark fear and uncertainty, rather than leaving women feeling better informed, researchers reported Dec. 3 in The BMJ.

“Women are more anxious, are confused by the notification, and do not feel more informed to make decisions about their breast health despite having increased knowledge,” concluded the research team led by Brooke Nickel, a research fellow with the University of Sydney School of Public Health in Australia.

Between 25% to 40% of women have dense breasts, researchers said in background notes.

Dense breast tissue can hide small cancers on a mammogram, making the tumors harder to detect, researchers said. It also can distort mammogram imaging, causing false positive readings that require further scans.

The U.S. Food and Drug Administration in 2024 mandated that all women be notified of their breast density following mammograms, and other nations like Australia and the U.K. are weighing whether to follow suit.

However, it’s not known whether this information actually helps women make better decisions about their breast health, researchers said.

For the new study, researchers performed mammograms on more than 2,400 Australian women with dense breasts and then randomly assigned them to one of three groups.

One group was not told they had dense breasts, the second was told they had dense breasts and handed written information about the implications of this condition, and the third was told of their dense breasts and provided a link to an online video with more information about breast density.

The research team checked back in with the women 8 weeks later and found the news had caused turmoil for some.

Compared to those who weren’t notified, women informed that they had dense breasts were:

• 28% to 30% more likely to be anxious

• 76% to 92% more likely to be confused

• Up to twice as likely to want to talk to their family doctor about what to do with the knowledge

Unfortunately, women told they had dense breasts also didn’t feel more informed, despite receiving either written information or a video explaining the implications of their condition, researchers found.

“Although notified women were more knowledgeable about breast density, this did not translate into women’s perceptions of feeling informed to make decisions about their breast health,” the research team wrote.

The researchers concluded that “findings from this trial show that notification as a population strategy to inform women may not be effective, as it found that women did not feel significantly more informed.”

The problem is that there’s no agreed-upon strategy for how to best provide follow-up breast cancer screenings for women with dense breasts, researchers said.

Additional scans using ultrasound, MRI and enhanced mammography can help detect cancers in women with dense breasts, but no guidelines have been set for how to inform women of these options, researchers said.

“Findings show that women may become confused and some may plan to turn to general practitioners for advice; in the absence of consensus on best management of dense breasts, general practitioners may not be well placed to provide definitive recommendations,” researchers wrote.

More information

The American Cancer Society has more on breast density and mammography.

SOURCES: BMJ, news release, Dec. 4, 2025; The BMJ, Dec. 4, 2025