Ovarian Ablation and Letrozole as Treatment for Premenopausal Women with Metastatic Breast Cancer

Purpose: To assess the efficacy and safety of ovarian ablation followed by letrozole as a first or second-line treatment for premenopausal women with metastatic breast cancer (MBC).Patients and method: Premenopausal women with estrogen receptors and/or progesterone receptor positive MBC, received ovarian ablation by radiotherapy (16Gy in 4 consecutive fractions) followed by letrozole tablets 2.5mg by mouth daily.Results: Between May 2010 and March 2013 thirty-five patients were eligible and included in the study. Twenty-four patients (68.6%) had bone metastases and half of patients (n=18; 51.4%) had only one metastatic site. Twelve (34.3%) patients achieved partial response (PR) and 11 had (31.4%) stable disease (SD). The clinical benefit rate (PR+ SD) was 65.7%. With a median duration of follow-up 24 months the median progression-free survival (PFS) was 7 months and the median overall survival was 18 months. Longer PFS was significantly observed in patients with one metastatic site, HER2/neu negative and longer disease-free interval when used as a first-line therapy. No serious toxicities secondary to letrozole or radiotherapy were reported.Conclusion: The results suggest that ovarian ablation by radiotherapy followed by letrozole is an effective first-line treatment for premenopausal women with hormonal receptor positive MBC.