Effects of anastrozole on cognitive performance in postmenopausal women: a randomised, double-blind chemoprevention trial (IBIS II).

Background: Mild cognitive impairments have been recorded in cross-sectional studies of women with breast cancer receiving endocrine treatment. More comprehensive studies were warranted because aromatase inhibitors are being used increasingly in both chemoprevention and adjuvant settings. We report findings from the cognitive subprotocol of the International Breast Intervention Study (IBIS II), a double-blind placebo-controlled trial of anastrozole in postmenopausal women at high risk of developing breast cancer.