This book contributes to health services research on the (further) development of care models aimed at optimizing cross-sectoral care, enhancing patient orientation, and improving cost-effectiveness. In the context of a prospective longitudinal study with an intervention and control group examination, a comparison was made between women with breast cancer who were cared for by the Augsburg support center for women with breast cancer and those receiving conventional care. The goal was to analyze the effectiveness of case management. The results of this evaluation show that, in addition to improving psychosocial effects, initial trends towards cost reduction through case management can also be achieved.