title: Activity of fulvestrant in HER2-overexpressing advanced breast cancer.
abstract: BACKGROUND
  Human epidermal growth factor receptor 2 (HER2) overexpression increases the aggressiveness of breast cancer cells resulting in poorer prognosis. Patients with HER2-positive disease are less responsive to endocrine therapies. Trastuzumab monotherapy results in objective responses in only approximately 15% of patients. Fulvestrant retains activity in cells overexpressing HER2 that are resistant to other endocrine treatments. This retrospective study evaluated response to fulvestrant treatment among HER2-positive patients with advanced breast cancer (ABC).
  
  
  METHODS
  Clinical experience data from 10 treatment centres were pooled. Postmenopausal patients with predominantly hormone receptor-positive and HER2-positive disease were included. Clinical benefit (CB) was defined as the proportion of patients achieving a response to treatment (partial or complete) or stable disease lasting >/=6 months.
  
  
  RESULTS
  Data for 102 patients were analysed. Fulvestrant resulted in an overall CB rate of 42% (43/101) in HER2-positive patients and 40% (25/63) in patients with visceral disease. Median duration of treatment was 14.5 months (range 6-44 months). Fulvestrant showed activity up to the fourth line of endocrine therapy and up to the seventh line of overall therapy.
  
  
  CONCLUSIONS
  Results indicate that fulvestrant may be a suitable treatment option in extensively pre-treated patients with HER2-positive, hormone receptor-positive ABC. Further exploration of its use in this patient population is warranted.
authors.affiliation: Professorial Unit of Surgery, Division of Breast Surgery, University of Nottingham, Nottingham City Hospital, Nottingham, UK. Electronic address: john.robertson@nottingham.ac.uk.
authors.forename: J F R
authors.initials: JFR
authors.lastname: Robertson
authors.affiliation: Department of Internal Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria.
authors.forename: G G
authors.initials: GG
authors.lastname: Steger
authors.affiliation: Department of Gynaecologic Oncology, University of Leuven, Leuven, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Neven
authors.affiliation: Division of Medical Oncology, Treviglio Hospital, Treviglio, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Barni
authors.affiliation: Department of Obstetrics and Gynaecology, University Hospital Eppendorf, Hamburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Gieseking
authors.affiliation: Department of Medicine, European Institute of Oncology, Milan, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Nolè
authors.affiliation: Faculty of Medicine, Division of Medical Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Canada.
authors.forename: K I
authors.initials: KI
authors.lastname: Pritchard
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.
authors.forename: F P
authors.initials: FP
authors.lastname: O'Malley
authors.affiliation: Department of Clinical Oncology, Albert Einstein Hospital, Sao Paulo, Brazil.
authors.forename: S D
authors.initials: SD
authors.lastname: Simon
authors.affiliation: Department of Oncology, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: B
authors.initials: B
authors.lastname: Kaufman
authors.affiliation: Department of Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: L
authors.initials: L
authors.lastname: Petruzelka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D002277:Carcinoma / Q000188:drug therapy* / Q000378:metabolism; D017024:Chemotherapy, Adjuvant; D018450:Disease Progression; D004958:Estradiol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D000077267:Fulvestrant; D006801:Humans; D008875:Middle Aged; D008954:Models, Biological; D020360:Neoadjuvant Therapy; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D016896:Treatment Outcome; D015854:Up-Regulation
chemical_list: D018931:Antineoplastic Agents, Hormonal; D004958:Estradiol; D000077267:Fulvestrant; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human