Tailoring adjuvant endocrine therapy for premenopausal breast cancer

Findings from two clinical studies support the use of exemestane, an aromatase inhibitor, over tamoxifen in premenopausal breast cancer patients. In the SOFT trial, participants were randomized to 5 years of exemestane or tamoxifen plus ovarian suppression or to tamoxifen alone.

Findings from two clinical studies support the use of exemestane, an aromatase inhibitor, over tamoxifen in premenopausal breast cancer patients. In the SOFT trial, participants were randomized to 5 years of exemestane or tamoxifen plus ovarian suppression or to tamoxifen alone. The TEXT investigation, meanwhile, limited the treatment groups to just tamoxifen plus ovarian suppression and exemestane plus ovarian suppression. The addition of ovarian suppression to tamoxifen prolonged disease-free and overall survival rates compared with tamoxifen only—at 83.2% and 78.9%, respectively. Disease-free survival rates were even better, at 85.9%, with exemestane plus ovarian suppression; but overall survival was greatest with tamoxifen plus ovarian suppression, at 93.3%, vs. 92.1% for exemestane plus ovarian suppression and 91.5% for tamoxifen alone. However, adverse events of grade 3 or worse were lowest in the tamoxifen-only group. For both SOFT and TEXT, meanwhile, cancer recurrence occurred at a substantially lower rate.