Mypebs (my personal breast screening) is a European study that should last 6 years and recruit 80,000 women, aged between 40 and 70, in 5 countries (Italy, France, Israel, Belgium and the United Kingdom).
The defined objective of the study is to verify whether individualized screening, i.e. based on each woman's lifetime risk of developing breast cancer, would be more effective in reducing the number of advanced cancers (stage 2 and above) than current standard mass screening.
BUT IN REALITY, THE STUDY WILL SIMPLY BE LIMITED TO DETERMINING WHETHER INDIVIDUALIZED SCREENING WOULD NOT MISS TOO MANY SERIOUS CANCERS COMPARED TO STANDARD SCREENING.
This is called a "non-inferiority test". If the new screening, or individualized screening, miss less than 25% serious cancers more than in the standard screening, it will be arbitrarily considered as being " non-inferior ", and after all, the two methods would be considered equivalent.
In other words, the question is whether the new strategy is not less effective than the original one, assuming that if there are, for example, 24% (less than 25%) more serious cancers, the results are declared "non-inferior". The authors will argue that both types of screening are equally effective, and the study will be declared a success.
There are several methodological flaws on Mypebs study :
- Incomplete and misleading brochure given to participants, minimizing the problem of over-diagnosis and omitting the problem of over-treatment.
- There is no comparison group of "unscreened" women, which means that the over-diagnosis in the screened groups cannot be quantified compared to a group of unscreened women.
- The software used to "calculate" the individual risk of each woman according to her age, her personal and family history, her breast density, has no scientific validity and will be "tested" during the study with possible readjustments.
- Additional mammograms will be carried out for certain women included in the study from the age of 40 onwards, whereas the irradiation of the breast exposes them to a real risk of DNA chains breakage of the breast cells in this young age group.
To better understand the specificities and flaws of Mypebs, Cancer Rose has created a portal dedicated to studying and decoding the My PEBS study.
You can also find an analysis here, made by our statistician, Dr Vincent Robert: http://www.mypebs-en-questions.fr/index.php