title: Current Medical Treatment of Patients with Non-Colorectal Liver Metastases: Primary Tumor Breast Cancer.
abstract: BACKGROUND
  (Metastatic) breast cancer is a heterogeneous entity in which every disease subtype requires an individualized systemic treatment approach.
  
  
  METHODS
  We reviewed the currently available data regarding systemic therapy of breast cancer and present a review of historical and current treatment approaches, with the publications cited covering a time span from 1896 to the last ASCO 2015.
  
  
  RESULTS
  Systemic therapy of metastatic breast cancer may include chemotherapy, endocrine therapy, and targeted therapies (e.g. antibody-based approaches). Based on the patient's breast cancer subtype, these agents may be employed alone or in combination. Therefore, characterization of the phenotype of the disease is necessary and may include biopsy of the metastatic site. Novel therapeutic approaches include immunologic therapies as well as PARP, PI3K and CDK 4/6 inhibitors, which are currently under investigation in clinical trials.
  
  
  CONCLUSIONS
  Systemic therapy of metastatic breast cancer requires complex and individualized treatment approaches that are best offered in an interdisciplinary setting.
authors.affiliation: Department of Gynecology and Obstetrics, University Hospital Schleswig-Holstein - Campus Lübeck, Lübeck, Germany.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Liedtke
authors.affiliation: Department of Gynecology and Obstetrics, Marienhospital Bottrop, Bottrop, Germany.
authors.forename: Hans-Christian
authors.initials: HC
authors.lastname: Kolberg
keywords: Chemotherapy; Endocrine therapy; Metastatic breast cancer; Signal transduction; Targeted therapy