Suppression of ovarian function in combination with an aromatase inhibitor as treatment for advanced breast cancer in pre-menopausal women

Trials have shown superiority of aromatase inhibitors (AIs) over tamoxifen for post menopausal oestrogen receptor positive advanced breast cancer (ER + ABC) We previously reported the use of goserelin plus anastrozole (G + A) as second line endocrine therapy for pre menopausal ER + ABC We report clinical and endocrine data from G + A as first line systemic therapy Thirty six patients (median age = 44 years) with metastatic (N = 28) and locally advanced disease were administered G + A for >= 6 months (unless progressed prior) Some (N = 13) received further therapy with goserelin plus another AI (steroidal), exemestane (G + E) Serial serum hormone assays (oestradiol dehydroepiandrosterone sulphate testosterone follicle stimulating hormone and luteinising hormone) were performed Twenty four patients (67%) derived clinical benefit (CB) (5% complete response 31% partial response 31% stable disease for 6 months) with median time to progression and duration of CB of 12 (2-47) and 24 + (7-78+) months respectively Ten patients were still receiving first line G + A at analysis Amongst 13 patients who went onto receive G + E 38% achieved CB with a mean duration of 13+(7-32) months Therapy was well tolerated with no withdrawals The combination of G + A resulted in 98% reduction (from pre treatment to 6 month) in median levels of oestradiol (from 574 5 pmol/L inter quartile range (IQR) = 209-1426 (N = 6) to 13 45 pmol/L IOQ = 5 5-31 5 (N = 4) whilst the levels of other hormones had minimal fluctuations during therapy The combinations of ovarian function suppression (using G) and AIs produce sus tamed CB and minimal side effects in pre menopausal ER + ABC with significant reduction in oestradiol levels Within the limitations of being a non randomised study they should be considered in appropriate patients with hormone sensitive ABC (C) 2010 Elsevier Ltd All rights reserved