Combined ovarian ablation and aromatase inhibition as first-line therapy for hormone receptor-positive metastatic breast cancer in premenopausal women: report of three cases

Aromatase inhibitors have become well established for the treatment of postmenopausal women with hormone receptor-positive metastatic breast cancer and for adjuvant hormonal therapy for primary breast cancer. Benefit of aromatase inhibition has not yet been extended to premenopausal women. Ovarian ablation by oophorectomy, ovarian radiation or hormonal suppression is the initial recommended treatment for hormone receptor-positive metastatic breast cancer in premenopausal women. The addition of tamoxifen improves the benefit of ovarian ablation/ovarian suppression. Addition of aromatase inhibitors to luteinizing hormone-releasing hormone analogs has been reported to significantly decrease circulating estrogens and produce tumor responses in only a very small number of patients over the last 15 years. We treated three premenopausal patients with hormone receptor-positive metastatic breast cancer with combined oophorectomy or ovarian irradiation and anastrozole. One patient remained free of progression for 4 years, while the other two remained free of progression for more than 5 and 3 years, respectively. We also note that monthly zoledronic acid for 4 years produced sclerosis of vertebral body metastasis. We conclude that combined ovarian ablation and aromatase inhibition is a feasible treatment modality that deserves more attention and further investigation for hormone receptor-positive metastatic breast cancer in premenopausal women.