Women's responses to information on mammographic breast density.

The objective of this study was to determine the negative and positive outcomes of providing mammographic breast density (MBD) information to participants of a screening program. A randomized experiment was conducted with a sample of 618 women 50 years or older with MBD greater than 50% of breast volume. The intervention consisted of reporting the presence of MBD in the screening mammography results letter that was sent along with an information pamphlet. Compared to the controls, more women in the intervention group described the term breast density correctly and recognized it as a risk factor for breast cancer. Although at the 4-week follow-up the intervention group indicated that they were "very likely" to have an annual clinical breast examination more frequently than controls, no differences were detected at 6 months. There were no significant differences on other behavioural or psychological measures, although at the 4-week follow-up the control group perceived their risk for breast cancer, relative to other women their age, as "a lot lower" than did women in the intervention group. The results demonstrate a feasible and non-threatening way to provide women with important personalized information about breast cancer risk.