Each year more than 26,000 cases are diagnosed in Spain. The medical expense will depend on the stage at time of detection. The highest cost component is chemotherapy. The two main determinants of the total cost of breast cancer are the initial treatment of stages I to III and the cost of stage IV reaching the latter € 50,061 per patient. The patient’s adherence to the process of diagnosis and monitoring, as well as the pharmacological, dietary and physical activity indications, generate more value in the disease process.