Author Affiliations: German Breast Group, Neu-Isenburg, Germany (firstname.lastname@example.org).
To the Editor: The relative risk reduction in the occurrence of early menopause in premenopausal patients with breast cancer undergoing chemotherapy achieved by adding a gonadotropin-releasing hormone (GnRH) analogue was 72% in the PROMISE-GIM6 (Prevention of Menopause Induced by Chemotherapy: a Study in Early Breast Cancer Patients—Gruppo Italiano Mammella 6) trial, but the absolute difference was 17%.1 Larger patient cohorts, including patients independent of hormone receptor status and aged between 40 and 45 years who might not derive any benefit from GnRH analogues, will be needed to demonstrate statistically significant but smaller clinical benefits.2
Loibl S, Gerber B. Gonadotropin-Releasing Hormone Analogue for Premenopausal Women With Breast Cancer. JAMA. 2011;306(16):1760-1761. doi:10.1001/jama.2011.1516