Activity of fulvestrant in HER2-overexpressing advanced breast cancer.
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.
Robertson
J F R
JFR
Professorial Unit of Surgery, Division of Breast Surgery, University of Nottingham, Nottingham City Hospital, Nottingham, UK. Electronic address: john.robertson@nottingham.ac.uk.
Steger
G G
GG
Department of Internal Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria.
Neven
P
P
Department of Gynaecologic Oncology, University of Leuven, Leuven, Belgium.
Barni
S
S
Division of Medical Oncology, Treviglio Hospital, Treviglio, Italy.
Gieseking
F
F
Department of Obstetrics and Gynaecology, University Hospital Eppendorf, Hamburg, Germany.
Nolè
F
F
Department of Medicine, European Institute of Oncology, Milan, Italy.
Pritchard
K I
KI
Faculty of Medicine, Division of Medical Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Canada.
O'Malley
F P
FP
Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.
Simon
S D
SD
Department of Clinical Oncology, Albert Einstein Hospital, Sao Paulo, Brazil.
Kaufman
B
B
Department of Oncology, Sheba Medical Center, Tel Hashomer, Israel.
Petruzelka
L
L
Department of Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic.
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
D018931:Antineoplastic Agents, Hormonal; D004958:Estradiol; D000077267:Fulvestrant; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human