[Public health problems related to chemoprevention of cancers].

The chemoprevention sets down numbers of problems and requires certain number of conditions. First of all, one has to demonstrate the action's effectiveness by a randomised trial using the appropriate effectiveness indicators and to confirm the results of the trial by a pilot prevention's project. The action shouldn't have neither inconvenient nor major risks. In numerous prevention's action, the inconvenient are superior to the benefits. The action should be aware of respecting the major ethical aspects: respect the person's autonomy, don't to be harmful, respect the equity and be beneficial; it also has to avoid important psychological consequences. At last, the prevention's action has to appeal to cost effectiveness strategy.