Tamoxifen versus aromatase inhibitors for the adjuvant treatment of breast cancer in older women: A feasibility study to examine differences in cognitive outcomes.

Abstract

TPS626Background: Tamoxifen (TAM) and aromatase inhibitors (AIs) are the mainstay endocrine therapies (ETs) for the treatment of hormone-receptor-positive (HR+) breast cancer (BC). While these ETs dramatically improve BC outcomes by reducing estrogen activity, increased awareness of the neuroprotective effects of estrogen on cognition has led to concerns regarding potential adverse cognitive effects. Cognitive concerns are heightened by the fact BC is more common among older women, who are already at greater risk of cognitive impairment (CI). While the anti-estrogen properties of TAM and AIs are unique, their differential effect on cognition remains unknown. Our overarching objective is to compare the cognitive effects of TAM and AIs in older women; however, before undertaking the large multicenter study needed to meet this goal, we are conducting a feasibility study to i) establish metrics on participation, retention, and ET adherence, and ii) inform sample size calculation for the future multicenter stu...