Anastrozole had little or no effect on cognitive function in women at high risk for breast cancer

Anastrozole did not impair cognitive function in postmenopausal women at high risk for breast cancer in a recently published study.

Researchers from the Brighton and Sussex Medical School at the University of Sussex, and other sites in the UK, conducted a double-blind, placebo-controlled trial — the International Breast Intervention Study — to determine the effects of anastrozole (Arimidex, AstraZeneca) on memory and attention in postmenopausal women at high risk for breast cancer.

The study included 227 postmenopausal women who underwent cognitive testing at baseline and were randomly assigned to placebo (n=116) or 1 mg/day anastrozole for five years (n=111). Cognitive task scores were obtained at baseline, six and 24 months.

Ten participants from each group were excluded at six months. At 24 months, 24 were excluded from the treatment group and 32 from placebo, leaving a total of 151 women in the study. The researchers reported no difference between the two groups for any cognitive tasks.

Thirteen participants in both groups reported memory changes at six months. However, that number decreased to five participants in the placebo group and three in the treatment group at 24 months.

At 24 months, the only difference in reported endocrine symptoms was hot flushes, which occurred more often in the treatment group than in placebo (23 of 76 vs. 11 of 73; P=.032).

Lancet Oncol. 2008;doi:10.1016/S1470-2045(08)70207-9