Cohort study of outcomes with adjuvant anastrozole, letrozole, or exemestane in patients with postmenopausal breast cancer

Third-generation aromatase inhibitors (anastrozole, letrozole, and exemestane) are standard adjuvant endocrine therapy for women with postmenopausal HR-positive early-stage breast cancer. A retrospective cohort study in France investigated the comparative effectiveness of these three agents.The patient cohort consisted of 148,436 women aged 50 to 75 years, diagnosed with early-stage breast cancer between 2011 and 2020, with follow-up through 2021. The study found that exemestane was associated with lower disease-free survival and overall survival at 8 years compared with anastrozole and letrozole, both under natural and perfect persistence. The authors conclude that these findings suggest higher risks of recurrence and death with exemestane and thus may favor anastrazole and letrozole as initial treatment.