title: Current status and future perspectives in the endocrine treatment of postmenopausal, hormone receptor-positive metastatic breast cancer.
abstract: BACKGROUND
  Endocrine therapy is a fundamental component of the therapeutic repertoire for treatment of metastatic, hormone receptor-positive breast cancer. Inevitably, however, tumors develop resistance to these compounds, and overcoming this phenomenon is a key motivator of research in this field.
  
  
  METHODS
  This review summarizes the current status of endocrine therapy for the treatment of metastatic disease, with a main focus on postmenopausal patients. Furthermore, strategies that could potentially sustain endocrine resistance and future perspectives in this direction are also to be described. Relevant references were identified by PubMed searches and from the abstract books of the annual meetings of The European Society of Clinical Oncology (ESMO), The American Society of Clinical Oncology (ASCO) and from the San Antonio Breast Cancer Symposia.
  
  
  CONCLUSIONS
  Combinations of endocrine therapy with HER2 targeting agents, as well as with compounds that can interfere with PI3K/Akt/mTOR signaling, are two promising strategies for delaying or overcoming endocrine resistance, mediated by these relevant biological pathways. Due to increased costs and the burden of toxicity associated with these combination therapies, compared to endocrine therapy alone, it is imperative to concentrate efforts on establishing biomarkers that can predict efficacy.
authors.affiliation: Institute for Cancer Research, Unit of Investigative Clinical Oncology (INCO), Candiolo, Italy. filippo.montemurro@ircc.it
authors.forename: Filippo
authors.initials: F
authors.lastname: Montemurro
authors.forename: Valentina
authors.initials: V
authors.lastname: Rossi
authors.forename: Elena
authors.initials: E
authors.lastname: Geuna
authors.forename: Giorgio
authors.initials: G
authors.lastname: Valabrega
authors.forename: Rossella
authors.initials: R
authors.lastname: Martinello
authors.forename: Andrea
authors.initials: A
authors.lastname: Milani
authors.forename: Massimo
authors.initials: M
authors.lastname: Aglietta
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D047072:Aromatase Inhibitors / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D017698:Postmenopause / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human