Notifying women that they have dense breasts may increase anxiety and confusion without improving understanding, according to a large Australian randomised controlled trial conducted within a population-based breast screening programme. The study, carried out in Queensland, involved women aged 40 years and older who attended routine screening and were classified as having mammographically dense breasts, defined as BI-RADS categories C or D using an automated density measure.
Between September 2023 and July 2024, 3,107 women were randomly assigned to one of three groups. One group received standard care with no notification of breast density. A second group was notified of their dense breasts and given written information designed to be sensitive to health literacy levels. A third group received density notification alongside a link to online video-based information with similar health literacy considerations. A total of 2,401 women were included in the final analysis, with a mean age of 57.4 years.
Psychological Impact And Intentions
At eight weeks after screening, women who were notified of having dense breasts reported significantly worse psychological outcomes than those who were not notified. Compared with the control group, notified women were more likely to feel anxious and confused. The odds of feeling anxious were 30% higher in the written information group and 28% higher in the video information group. Feelings of confusion were nearly doubled in the written information group and increased by around 76% in the video group.
Despite receiving additional information, notified women did not feel more informed about their breast health. In fact, the likelihood of feeling informed was slightly lower in both intervention groups compared with standard care.
Notification also influenced intended use of health services. Women who were told they had dense breasts were more likely to intend to consult their general practitioner about their screening results and to rely on their GP for advice on supplemental screening. However, most women across all groups did not plan to undergo additional screening, although intentions were somewhat higher among notified women.
Implications For Screening Policy
The researchers conclude that notifying women of breast density within population-based screening programmes may have unintended adverse effects. While notification increased intentions to seek advice from general practitioners, it did not empower women to feel informed or confident in decision making. The findings suggest that widespread breast density notification could place additional consultation demands on general practice without clear benefits for informed choice or screening behaviour.
Reference
Nickel B et al. Impact of population based breast density notification: multisite parallel arm randomised controlled trial in BreastScreen. BMJ 2025;391:e083649.
