The Intergroup Exemestane Study (IES) yielded data showing that hormone- sensitive postmenopausal early breast cancer patients who switched from tamoxifen to Aromasin (exemestane) were 17% more likely to be alive and 25% less likely to see their cancer return than patients who remained on tamoxifen for 5 years. These study findings stem from almost 5 years of followup of the IES trial, a large, randomized, double-blind, multinational trial comparing 2352 patients taking Aromasin following tamoxifen therapy with 2372 patients remaining on tamoxifen therapy for 5 years. The IES produced early results that prompted the FDA and European regulatory approvals for Aromasin. These findings showed that 85% of patients in the trial were postmenopausal hormone receptor-positive, and those who switched to Aromasin reduced their risk of breast cancer recurrence by 35%, compared with the tamoxifen group. Previously, no difference in survival rates had been noted. Side effects were mild to moderate and included hot flashes, fatigue, arthralgia, headache, insomnia, and increased sweating.
Ms. Farley is a freelance medical writer based in Wakefield, RI.