Anastrozole and goserelin combination as first treatment for premenopausal receptor positive advanced or metastatic breast cancer: A phase II trial.

1079 Background: Aromatase inhibitors (AIs) have shown high activity in postmenopausal women. However, as AIs do not suppress ovarian oestrogen synthesis, they are not effective in premenopausal women. The aim of this trial was to assess the efficacy of the combination of anastrozole and goserelin (LHRH agonist) in premenopausal women with advanced or metastatic hormonal receptor positive breast cancer. METHODS Premenopausal women with advanced estrogen receptor (ER) and/or progesterone receptor (PR) positive breast cancer were enrolled in this open, multicentre, non-comparative phase II trial and received anastrozole 1mg/day p.o. and gosereline 3.6 mg subcutaneously monthly until progression. The primary endpoint was objective response rate (ORR) assessed according to RECIST criteria. RESULTS Thirty-three patients (33), with a mean age of 44 (+ 5.9) years, PS 0-2, were enrolled from December 2001 to May 2005. All patients were ER positive and 75.8% PR positive and 6 patients (18.2%) received adjuvant treatment with anti estrogens. There were 4 (12.1%) complete responses (CR), 14 (42.4%) partial responses (PR), and 11 (33.3%) stable diseases (SD), giving an ORR of 54.6% (IC 95% [36.4; 71.9]). Twenty-one (63.6%) patients showed a clinical benefit (CR+PR+SD≥24 weeks) for a median duration of 13.7 (IC 95% [8.74; 22.97]) months. Median time to progression was 13 (6;33) months. The most commun AEs were hot flush in 29 (87.9%), arthralgia in 13 (39.4%) and nausea in 12 (36.4%) patients. CONCLUSIONS The combination of anastrozole and gosereline is well tolerated and appears to be an effective treatment of premenopausal women with advanced breast cancer in this exploratory phase II trial. No significant financial relationships to disclose.