Extended adjuvant intermittent letrozole versus continuous letrozole in postmenopausal women with breast cancer (SOLE): a multicentre, open-label, randomised, phase 3 trial

At 5 years' follow-up, disease-free survival did not differ significantly between 4851 postmenopausal women who received extended intermittent letrozole and those given continuous letrozole (85.8% vs 87.5%; HR, 1.08, 95% CI 0.93–1.26; p=0.31).

A related commentary notes that the inclusion of previous tamoxifen users complicates interpretation of these findings.