Women’s Acceptance of Overdetection in Breast Cancer Screening: Can We Assess Harm-Benefit Tradeoffs?

Background. Breast cancer screening has been presented to women as mostly positive for decades, despite voices raising issues related to harms since its introduction. Public communications about breast cancer screening tended to use persuasive techniques aimed at maximizing uptake. Concern about the harm of overdetection is more recent, and awareness of overdetection among the public is limited. We aimed to assess the impact of extensive information on treatment following overdetection in breast screening on women’s acceptance of screening, and to assess correlates of acceptance. Methods. We performed an online survey among women aged 45-75 from the general public in the Netherlands and Australia, asking women their maximum acceptable ratio of overdetection, per breast cancer death avoided, for four treatment scenarios (randomized order): mastectomy; lumpectomy; lumpectomy plus radiotherapy; lumpectomy plus radiotherapy and hormone therapy. The effect of treatment was assessed using General Linear Models, controlling for socio-demographics, experience, and psychological characteristics. Results. Four-hundred Australian and 403 Dutch women responded. Around half of the women would always screen, even at a 6:1 overdetection-to-death-avoided ratio. Acceptance was highest for the lumpectomy scenario, decreasing with more invasive treatment. In multivariate analyses the effect of treatment remained (p<0.001). Higher acceptance was seen for women with children (p=0.04), screening experience (p<0.001), and less understanding of overdetection (p<0.001). A learning effect was seen: acceptance was highest for the first scenario shown. Conclusions. Acceptance of overdetection was high, but decreased after the first scenario and with invasiveness of treatment. This provides a first indication that with more knowledge and understanding, women may move from uncritical acceptance of screening towards a more informed decision that involves a trade-off of the benefits and harms.