ESMO 2017: Comparison of Two Adjuvant Therapies for Early Breast Cancer
A study presented at the 2017 European Society for Medical Oncology (ESMO) Congress (Abstract 148O) evaluated the addition of fulvestrant to anastrozole, versus anastrozole alone in hormone receptor–positive/HER2-negative postmenopausal women. This phase III GEICAM-2006-10 trial led by Manuel Ruiz-Borrego, MD, PhD, of Hospital Universitario Virgen del Rocio, Seville, Spain, did not find statistically significant differences in disease-free survival between the two groups. However, the investigators noted that no formal conclusion could be made from this trial due to the dose of fulvestrant given (250 mg) and the sample size.
From January 2008 to June 2010, 872 patients were randomized to receive anastrozole (n=437) or anastrozole plus fulvestrant (n=435). Treatment was completed in 72.5% of the anastrozole group and 48.5% of the fulvestrant group.
Grade 2 and 3 toxicities affected patients in both the anastrozole and fulvestrant groups, including hypertension (13.2% vs. 9.9%), fatigue (5.2% vs. 11.8%), low density lipoprotein–cholesterol increase (9.4% vs. 5.3%), osteoporosis (5.5% vs. 6.9%), and musculoskeletal bone and joint pain (26.3% vs. 29.4%).
At a median follow-up of 6.3 years, 90.77% of the single-therapy group and 91.25% of the doublet-therapy group were disease free after 5 years. Breast cancer relapse occurred in 10.5% and 8.3%, respectively. Survival and breast cancer–specific survival were not reached.