Do Adverse Effects Foretell Efficacy of Adjuvant Aromatase Inhibitor Therapy for Breast Cancer?

Some reports have suggested that treatment-associated vasomotor symptoms (VMS) or arthralgias predict better response to aromatase inhibitor (AI) therapy. Investigators analyzed data from a trial in which 7344 menopausal women with receptor-positive invasive breast cancer were randomized to exemestane or anastrozole.

Preexisting vasomotor or joint symptoms were reported by 34% of participants. Among women without such symptoms at baseline, treatment-emergent symptoms occurred in 25% at 6 months and 52% at 12 months. At a median follow-up of 4 years, neither the baseline presence of these symptoms nor their development during the trial affected relapse-free survival.