Women undergoing adjuvant chemotherapy for breast cancer treatment complain of cognitive difficulties especially with memory, word recall, and concentration. Commonly referred to as “chemo brain”, some studies suggest that up to 40 to 80% of women may experience some decline in cognitive function, while others have found no cognitive decline associated with treatment. We examined symptoms associated with chemo brain among women treated with chemotherapy and/or aromatase inhibitors (AIs) compared to age-matched healthy controls.


Women diagnosed with breast cancer (n = 180) and age-matched healthy controls (n = 149) were recruited to participate in an observational study on the side effects of AI treatment. Cases were stratified according to treatment at the time of enrollment: adjuvant chemotherapy only, AI therapy only, or both. Participants were asked the extent to which they were bothered by forgetfulness and difficulty concentrating over the past 4 weeks. The severity of each symptom was classified as none, slightly, and moderately/quite a bit/extremely.


The ages of cases and controls were similar (mean: 61.6 versus 60.8 years; p-value= 0.5). Of the cases, 19% were treated with chemotherapy only and 47.7% were treated with AIs only; 33.3% were treated with both. Among the cases, women only treated with AIs were older than women treated with chemotherapy (mean: 65.4 versus 57.9 years; p-value < 0.0001). Women who received chemotherapy were more likely to report difficulty concentrating and forgetfulness than controls (34.8% versus 17.9%; p-value <0.0001 and 30.4% versus 9.7%; p-value <0.015, respectively). These differences remained statistically significant after adjustment for age. Associations were similar for those treated with chemotherapy compared to those with chemotherapy and AIs. Treatment with AIs only was not associated with symptoms of forgetfulness or difficulty concentrating compared to controls (p-values= 0.1 and 0.8 respectively).


Chemotherapy, but not AI therapy, was associated with difficulty concentrating and increased forgetfulness. The association was present despite patients treated with chemotherapy being significantly younger than controls. Hormone deprivation did not appear to exacerbate the symptoms, although the sample size was limited to explore this interaction.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B20.

Seventh AACR International Conference on Frontiers in Cancer Prevention Research-- Nov 16-19, 2008; Washington, DC