This paper presents two applications for the breast cancer treatment decision helping. The first one is called Casimir/RBR and can be likened to a rule-based reasoning system. It is now fully implemented. In some situations, the application of the rules of this system does not provide a satisfying treatment. Then, the application Casimir/CBR --which is not fully implemented-- can be used. Casimir/CBR uses principles of case-based reasoning in order to suggest solutions by adapting the rules of Casimir/RBR. In this framework, the rules are considered as cases: they are adapted rather than used literally.