Fulvestrant, formerly ICI 182,780, is as effective as anastrozole in postmenopausal women with advanced breast cancer progressing after prior endocrine treatment.
OBJECTIVE
To compare the efficacy and tolerability of fulvestrant (formerly ICI 182,780) and anastrozole in postmenopausal women with advanced breast cancer progressing after prior endocrine treatment.


METHODS
Patients (n = 451) with advanced breast cancer were randomized to receive fulvestrant 250 mg as a once-monthly (one x 5 mL) intramuscular injection or an oral dose of anastrozole 1 mg in this open, parallel-group, multicenter trial. The primary end point was time to progression (TTP). Secondary end points included objective response (OR) rates, defined as complete response (CR) or partial response (PR), duration of response (DOR), and tolerability.


RESULTS
Patients were followed for a median period of 14.4 months. In terms of TTP, fulvestrant was as effective as anastrozole (hazard ratio, 0.98; confidence interval [CI], 0.80 to 1.21; P =.84). Median TTP was 5.5 months for fulvestrant and 5.1 months for anastrozole. OR rates showed a numerical advantage for fulvestrant (20.7%) over anastrozole (15.7%) (odds ratio, 1.38; CI, 0.84 to 2.29; P =.20). Clinical benefit rates (CR + PR + stable disease > or = 24 weeks) were 44.6% for fulvestrant and 45.0% for anastrozole. Median DOR was 14.3 months for fulvestrant and 14.0 months for anastrozole. Both treatments were well tolerated, with 3.2% and 1.3% of fulvestrant- and anastrozole-treated patients, respectively, withdrawn from treatment because of an adverse event.


CONCLUSIONS
Fulvestrant was as effective as anastrozole. These data confirm that fulvestrant is an additional, effective, and well-tolerated treatment for advanced breast cancer in postmenopausal women whose disease progressed on prior endocrine therapy.
Howell
A
A
Department of Medical Oncology, Christie Hospital NHS Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom. maria.parker@christie-tr.nwest.nhs.ukto
Robertson
J F R
JF
Quaresma Albano
J
J
Aschermannova
A
A
Mauriac
L
L
Kleeberg
U R
UR
Vergote
I
I
Erikstein
B
B
Webster
A
A
Morris
C
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077384:Anastrozole; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D018572:Disease-Free Survival; D004958:Estradiol / Q000009:adverse effects / Q000031:analogs & derivatives / Q000627:therapeutic use*; D004965:Estrogen Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D000077267:Fulvestrant; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009570:Nitriles / Q000009:adverse effects / Q000627:therapeutic use*; D017698:Postmenopause; D011788:Quality of Life; D015996:Survival Rate; D014230:Triazoles / Q000009:adverse effects / Q000627:therapeutic use*
D018931:Antineoplastic Agents, Hormonal; D004965:Estrogen Antagonists; D009570:Nitriles; D014230:Triazoles; D000077267:Fulvestrant; D000077384:Anastrozole; D004958:Estradiol