The use of the aromatase inhibitor Arimidex® (anastrozole) does not appear to be associated with cognitive impairment among postmenopausal women at a high risk of developing breast cancer. These results were recently published in the Lancet Oncology.
The majority of breast cancers are hormone positive, meaning the cancer cells are stimulated to grow from exposure to the female hormones estrogen and/or progesterone. Women with hormone-positive breast cancer receive hormone therapy, a type of therapy that prevents estrogen from forming in the body or prevents exposure of cancer cells to estrogen. Arimidex is a type of hormone therapy that is commonly used among postmenopausal women with hormone-positive breast cancer. It is also being evaluated for the prevention of breast cancer among women who are at a high risk of developing the disease.
Women undergoing therapy for breast cancer often complain of cognitive impairment as a side effect of therapy. Specifically, declines in attention and memory appear to be a common complaint for this group of women. Research into a cause of these issues is being conducted. Because Arimidex is being evaluated as a preventive measure against the development of breast cancer, associated side effects become particularly important as the drug would be used among women who are otherwise healthy.
Researchers from the United Kingdom recently conducted a subgroup analysis from a clinical trial to explore a potential relationship between Arimidex and cognitive impairment among women who had a high risk of developing breast cancer. This analysis was performed from a clinical trial that compared Arimidex to placebo (inactive substitute) for breast cancer prevention among postmenopausal women. Data was gathered to measure psychological effects and hormone symptoms, including a self-reported cognitive evaluation among 151 women who were treated with either Arimidex or placebo. Cognitive assessments were performed prior to any therapy (baseline) and again at six months and 24 months into therapy. Areas assessed included attention and memory loss.
- There was little, if any, cognitive impairment among women treated with Arimidex compared with those who received placebo.
- At 24 months hot flushes were significantly greater among women treated with Arimidex than those who received placebo.
The researchers concluded: “These findings show little or no impairment of cognitive performance with the use of anastrozole compared with placebo in postmenopausal women at high risk of developing breast cancer who were able to tolerate endocrine-related side-effects.” Future study concerning cognitive issues and breast cancer and its treatment is ongoing.
Reference: Jenkins V, Ambroisine L, Atkins L, et al. Effects of anastrozole on cognitive performance in postmenopausal women: a randomised, double-blind chemoprevention trial (IBIS II). The Lancet Oncology. 2008; 9:953-961.