gms | German Medical Science

Fulvestrant (Faslodex®) is a pure estrogen-receptor antagonist devoid of all estrogen receptor activity. Like tamoxifen, it binds to estrogen receptors competitively. Unlike tamoxifen, fulvestrant leads to rapid degradation and loss (“downregulation”) of estrogen receptors as well as a significant reduction of progesterone receptors. The efficacy of fulvestrant was shown in 2 randomised multicenter trials in postmenopausal women with metastatic breast cancer progressing on prior endocrine tamoxifen therapy.

The purpose of this retrospective analysis is to evaluate the therapeutic efficacy of fulvestrant in patients with heavily pretreated metastatic breast cancer in our departement.

Since 2004, 31 patients aged 50 – 84 years (median: 63) have received fulvestrant therapy. Thirty female patients were postmenopausal, our only male patient had pleural and bone involvement. All patients had received at least one (n=11) or more (n=20) prior endocrine therapies, 13 patients had received tamoxifen in an adjuvant setting, 7 patients had received tamoxifen in an metastatic situation. 11 patients presented with primary advanced disease. 14 of our patients had both estrogen (ER) and progesterone (PR) receptor positive disease. In 8 of 31 cases, an ER+/PR– situation was reported. Only one patient was ER–/PR+. The hormone receptor status was unknown in 8 cases. Twenty one patients (68%) had received palliative chemotherapy for lack of further endocrine options prior to the approval of fulvestrant. Response to therapy was monitored via clinical assessment, imaging and, where applicable, CA 15-3 and CEA levels.

Having received at least two 4-weekly fulvestrant 250 mg injections, 28 patients were eligible for evaluation of response. All 31 patients were evaluated for toxicity. A total of 150 injections were administered (median: 4; range: 1-11). Three patients are currently still receiving therapy. Partial response (PR) was achieved in 5 cases (18%) with a duration of response between 2 and 11 months. Four patients (14%) showed stable disease (SD) for 16 months and under current treatment, respectively. Hence, a clinical benefit was observed for 9 (32%) of our patients. Five of these patients were ER+/PR+; one ER–/PR+; two ER+/PR- and one of unknown receptor status. Noteworthy toxicity was not observed.

Endocrine therapy with fulvestrant is a veritable option for postmenopausal patients with advanced, hormone-receptor positive breast cancer. Clinical benefit (PR or SD) was observed in roughly 1/3 of our limited, largely heavily pretreated patient population.