Fulvestrant in heavily pretreated metastatic breast cancer: is it still effective as a very advanced line of treatment?
BACKGROUND
Over 75% of postmenopausal patients with metastatic breast cancer have hormone receptor-positive tumors. Endocrine therapy, with its more favorable toxicity profile than chemotherapy, is the preferred treatment modality for these patients.


OBJECTIVE
To assess our experience with fulvestrant, an antiestrogen, in an advanced phase of treatment, after progression on the classical anti-estrogen (tamoxifen) and aromatase inhibitors


METHODS
The study group comprised 46 patients with metastatic breast cancer treated with fulvestrant during the years 2002-2006. Fulvestrant was given monthly until disease progression or unacceptable toxicity.


RESULTS
The median number of fulvestrant cycles was 4.14 (range 1-32). Four patients are still on the treatment. The reasons for treatment discontinuation include disease progression (n=40), refusal (n=1), and allergic reaction (n=1). Ten patients (22%) achieved partial response and 22 (47%) had stable disease. Fourteen (30%) had disease progression with a response rate of 22% and a clinical benefit of 67%, and 14 (30%) had stable disease for > 6 months. Twenty-five patients (54%) are still alive, 4 (9%) without and 21 (45%) with disease progression. With a median follow-up of 15 months (range 1-30.1), the median time to progression was estimated to be 4 months (95% confidence interval 3.1-4.9), and the estimated overall survival 20.1 (95% CI 13.6 to upper limit; not reached yet). The 1 year estimated survival is 67%.


CONCLUSIONS
In terms of late-phase administration, fulvestrant still appears to have a good clinical effect, with a time to progression of 4 months and a clinical benefit > 60%, notably accompanied by only very mild toxicity. Irrespective of the line of treatment the patients received, the 4 month time to progression was constant and the medication was still working effectively in a very late line of treatment in metastatic breast cancer. Fulvestrant offers clinical benefit with very mild toxicity in a very heavily pretreated population and the medication is recommended, even in patients who received many lines of chemotherapy.
Safra
Tamar
T
Department of Oncology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
Greenberg
Julia
J
Ron
Ilan G
IG
Ben-Yosef
Rami
R
Inbar
Moshe
M
Sarid
David
D
Yaal-Hahoshen
Neora
N
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D047072:Aromatase Inhibitors / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D018450:Disease Progression; D004334:Drug Administration Schedule; D004958:Estradiol / Q000031:analogs & derivatives* / Q000627:therapeutic use; D004965:Estrogen Antagonists / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D000077267:Fulvestrant; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies; D020845:Selective Estrogen Receptor Modulators / Q000627:therapeutic use; D013629:Tamoxifen / Q000627:therapeutic use
D047072:Aromatase Inhibitors; D004958:Estradiol; D004965:Estrogen Antagonists; D000077267:Fulvestrant; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen