AgeX and MyPeBS breast screening trials – why bother informing women?
Bewley et al. are right to criticize the AgeX breast screening trial for poor science and public information (1).
Even in cluster randomized trials, radio, television and social networks can inform women. No supposed scientific necessity overrides this right. Indeed, opacity and lack of public information seems linked to bad science.
Same for the forthcoming European MyPeBS clinical trial comparing the incidence of advanced breast cancer after individualized breast cancer screening vs standard screening (2). (1). In the “individualized” group, women will be divided into 4 breast cancer risk subgroups - the higher the risk, the more extensive the screening, up to one mammogram and one MRI annually; (2). In the “standard” group, women will be invited to the usual screening. Problematically, in the individualized group, mammograms will start at age 40. All women under 50 will have more mammograms than women in the usual screening group.
In MyPeBS as in AgeX, financial costs and risks for women are increased. And for what? A result we can already anticipate. MyPeBS has a non-inferiority design with a threshold of 25%. So, if the individualized screening results in 25% more advanced breast cancer (and breast cancer mortality), it will be considered “non inferior” to usual screening. Even if it has no effect whatsoever on advanced breast cancer incidence.
Unsurprisingly, participant information is as minimal in MyPeBS as it was in AgeX: it minimises overdiagnosis and fails to mention overtreatment (3). We conclude that giving bad information to patients is linked to bad science.
1- S. Bewley and al. “Cost of extending the NHS breast screening age range in England” BMJ 2019;365:l1293
2- Unicancer - UCBG-screening - Protocole n° UC-0109/1805 de l’étude MyPeBS, Synopsis, 20 pages.
3- Unicancer - Protocole n° UC-0109/1805 « Brochure d’information et formulaire de consentement » Version 1.3, 24 juillet 2018, 16 pages.
Competing interests: No competing interests