[Methodology and legitimacy of French clinical trials in primary chemoprevention of cancers. The point of view of the National Federation of French cancer centers].

In connection with the breast cancer prevention trial (BCPT) controversy, the "Fédération nationale des centres de lutte contre le cancer" (FNCLCC) decided to clarify, with the help of various discipline experts, its position on chemoprevention trials. If in terms of inclusion, two approaches can be opposed: high relative risk versus high attributable risk, these trials share in common a considerable importance of the informed consent according to potentially prosecution. A particular attention should be given to the unambiguous definition of end-points and indicators, and to monitoring of the side effects (medical or not). Non medical actors would have to play significant interventions in the schedule, the follow-up and the evaluation of such protocols. Methodological difficulties have been pointed, for example: recruitment, observance, drop out and confounding factors. French specificity has to be taking into account for the choice of pathologies, kind of interventions and global evaluation non limited to the sole dimension of the medical efficiency.