Impact of population based breast density notification: multisite parallel arm randomised controlled trial in BreastScreen 

1. In this randomized controlled trial, breast density notification was associated with increased anxiety and confusion without helping women feel more informed.

Evidence Rating Level: 1 (Excellent)

High breast density, present in about 25–40% of women undergoing mammography, increases breast cancer risk and makes cancers harder to detect. Many countries, including the US and Australia, are notifying women of their breast density to inform them of this risk and the potential need for additional screening. However, the long-term benefits and harms of such notification remain unclear. This trial examines how telling women about dense breasts affects their psychological responses and intentions to use health services, and whether written versus video information changes these effects. A three-arm randomized controlled trial was employed to assess the goals of the study most effectively. Women aged ≥40 with dense breasts (BI-RADS C or D) were invited to participate and randomized, with primary outcomes assessed via online questionnaires eight weeks after screening. Randomization was blinded, and all outcomes were self-reported, including psychological responses and intentions to use health services. A total of 3107 women were randomized, with 2401 included in the analysis (mean age [SD] 57.4 [9.9] years). Women who were notified of their dense breasts reported higher levels of anxiety (control: 18.0%; intervention 1: 20.8%, odds ratio 1.30, 95% confidence interval (CI) 1.08 to 1.57 (P=0.005); intervention 2: 20.5%, odds ratio 1.28, 1.07 to 1.54 (P=0.007)) and confusion (intervention 1: 11.5%, odds ratio 1.92, 1.58 to 2.33 (P<0.001); intervention 2: 9.0%, odds ratio 1.76, 1.46 to 2.13 (P<0.001)) compared to the control group. Furthermore, the intervention group reported greater intentions to discuss results with their general practitioner (intervention 1: relative risk ratio 2.08, 95% CI 1.59 to 2.73; intervention 2: relative risk ratio 1.71, 1.31 to 2.25) and seek advice on supplemental screening (intervention 1: relative risk ratio 2.61, 1.80 to 3.79; intervention 2: relative risk ratio 2.29, 1.58 to 3.33) compared to the control group. Compared to the control group, there was no significant increase in women feeling informed to make decisions about their breast health for either intervention 1 (OR 0.83, 0.68 to 1.01; P=0.059) or intervention 2 (OR 0.80, 0.66 to 0.97; P=0.022). Overall, notifying women of dense breast status increased anxiety and confusion, did not make them feel more informed, and prompted most to seek guidance from their general practitioners. 

Click here to read this study in the BMJ

Image: PD

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