This book is an organic, multidisciplinary and comprehensive collection of articles aimed at clarifying the most important and the most innovative aspects in the local or systemic treatments of metastatic breast cancer. They are divided into seven sections: in the first section there is an interesting overview on metastatic breast cancer which mainly evaluates emerging new biomarkers and rare sites of breast cancer metastasis. There are also three sections dedicated to chemotherapy, endocrine therapy and target therapy (including immunotherapy). Local treatment strategies (radiotherapy, surgery) are also considered. There is also a specific section for the treatment of metastases in “special” sites such as brain and bone. Finally, there is a section dedicated to palliative care and the general management of this heterogeneous group of pathologies. This special book provides a set of research papers of high quality useful in order to optimize the clinical management of metastatic breast cancer by a multidisciplinary approach thanks to the contribution of important international authors.