[Participation to organized screening programs: Individual and collective stakes].

The evaluation of the risk-benefit balance in public health is an ethical commitment, based on the imperative of not harming people. Screening is a probabilistic approach, which, in order to serve the needs of a few, involves the largest number to share the potential harmful effects. Improvement of scientific knowledge and opening of the societal debate modified the relation between collective and individual stakes over time. This article traces the evolution of the discourse surrounding cancer screening, particularly following the controversy surrounding breast cancer screening. Within the framework of a health policy, screening leads in the first place to a collective benefit and second, to an individual benefit. It describes how, within the French context, the debate has induced a complete re-examination of the modalities of information and consent leading to a shift from the promotion of screening to more balanced information on benefits and risks, so that people can decide whether to participate in a more informed way.