Clinical efficacy of leuprorelin acetate monthly depot in premenopausal patients with metastatic breast cancer.

We included 58 premenopausal patients with metastatic breast cancer in an open study with leuprorelin acetate monthly depot. The overall response rate was 15/50 patients (30%). The median duration to tumour progression according to Kaplan-Meier analysis was 12 months. After leuprorelin acetate treatment permanent suppression of ovarian function was recorded with oestradiol levels below 30 pg/ml. The side effects were acceptable. The most common were: menopausal complaints, headache, dizziness and nausea. Changes of laboratory parameters were caused by cessation of ovarian function and progression of the underlying disease. Leuprorelin acetate is an effective drug for first line palliative treatment of premenopausal, metastatic breast cancer. The objective response rate is similar to other GnRH analogues and to reported data on surgical oophorectomy.