Exemestane Beats Tamoxifen in Early Breast Cancer
(HealthDay News) — For premenopausal women with hormone receptor-positive early breast cancer, exemestane plus ovarian function suppression (OFS) is superior to tamoxifen plus OFS. This finding was presented at the annual meeting of the American Society of Clinical Oncology, held from May 30–June 3 in Chicago.
Olivia Pagani, MD, from the Institute of Oncology of Southern Switzerland in Bellinzona, and colleagues examined the results from two randomized phase 3 trials, TEXT and SOFT, which enrolled 4,690 premenopausal women with hormone receptor-positive early breast cancer. The women were randomized to receive five years of exemestane plus OFS or tamoxifen plus OFS.
The researchers found that the five-year disease-free survival was 91.1% in the exemestane plus OFS group, compared with 87.3% in the tamoxifen plus OFS group, with a significant reduction in the risk of disease-free survival in the exemestane group (hazard ratio [HR], 0.72; P=0.0002). Similar reductions were seen for breast cancer-free interval (HR, 0.66; 95% confidence interval [CI], 0.55–0.80) and distant recurrence-free interval (HR, 0.78; 95% CI, 0.62–0.97), but there was no significant between-group difference noted in overall survival (HR, 1.14; 95% CI, 0.86–1.51).
"Our findings indicate that exemestane is better than tamoxifen, when given with ovarian function suppression, but longer follow up of these young women will be important to assess survival, and any long-term side effects and fertility," Pagani said in a statement.
The study was partially funded by Pfizer (manufacturer of exemestane) and Ipsen.