Purpose: Ovarian suppression with luteinizing hormone-releasing hormone (LHRH) agonists is an effective adjuvant treatment for premenopausal women with estrogen receptor (ER) -positive breast cancer. Whereas monthly LHRH agonist therapy has been well established, the value of every-3-months (3-monthly) formulations is unclear.
Patients and methods: This randomized phase III trial was performed to compare the 3-monthly depot LHRH agonist leuprorelin acetate (LAD-3M; n = 299) and chemotherapy with cyclophosphamide, methotrexate, and fluorouracil (CMF; n = 300) in pre- or perimenopausal patients with ER-positive, node-positive breast cancer.
Results: With a median follow-up of 5.8 years, recurrence-free survival was similar for patients treated with LAD-3M or CMF (hazard ratio [HR], 1.19; 95% CI, 0.94 to 1.51; P = .15). There was no substantial heterogeneity in the relative treatment effect among subgroups defined by age, progesterone receptor (PR) status, nodal status, hormone levels, or menstrual recovery after treatment. Exploratory overall survival analysis favored LAD-3M (HR, 1.50; 95% CI, 1.13 to 1.99; P = .005). Chemotherapy-related adverse effects such as nausea, vomiting, and alopecia were more common with CMF, whereas symptoms of estrogen suppression such as hot flushes and sweating were initially more pronounced with LAD-3M.
Conclusion: The 3-monthly depot LHRH-agonist leuprorelin acetate is an effective adjuvant treatment in premenopausal patients with hormone receptor-positive, node-positive breast cancer that is not inferior to CMF.