Mar Fan, H.G., Park, A., Xu, W., Yi, Q-L., Braganza, S., Chang, J., . . . & Tannock, I.F. (2009). The influence of erythropoietin on cognitive function in women following chemotherapy for breast cancer. Psycho-Oncology, 18(2), 156–161.

The study was conducted to investigate post-hoc the potential impact of erythropoietin on cognitive function following chemotherapy for breast cancer.

Patients were randomized when their hemoglobin (Hgb) level decreased to ≤ 12 g/dL. Depending on the remaining duration of chemotherapy, erythropoietin was administered for a period of time between 16 or 28 weeks. Patients were randomized to receive either 40,000 units of erythropoietin weekly or the standard of care.

• All participants were female and had breast cancer.
• Participants were selected from a primary study group receiving adjuvant chemotherapy.
• The number of participants was 87.
• The number of participants in the treatment group (erythropoietin arm) was 45.
• The number of participants in the control group (standard care) was 42.
• Participants spent an average of 23 months in the intervention group and 24 months in the standard-of-care group. 

This multi-site study took place in Canada.

The study was a randomized, controlled trial.

• Primary Cognitive Endpoint: Proportion with moderate-severe cognitive impairment at 12–30 months following completion of chemotherapy as measured by High Sensitivity Cognitive Screen (HSCS) for memory, language, attention, concentration, visual motor, spatial, and self-regulation
• Secondary Cognitive Endpoint: Proportion that scored in lowest quartile of any of four variables in the Hopkins Verbal Learning test–Revised (HVLT-R) for total recall, delayed recall percent retained, and discrimination index
• Functional Assessment of Cancer Therapy (FACT)-F for cancer-related quality of life specific to symptoms of fatigue
• Hospital Anxiety and Depression Scale (HADS) for anxiety and depression.

Participants showed no improvement in cognitive function or fatigue, as measured by the HSCS or HVLT-R. There was reported improvement in quality of life.

The study failed to demonstrate a protective effect of erythropoietin on cognitive dysfunction after chemotherapy in survivors of breast cancer.

• The study had a small sample size, given the variability in chemotherapy regimens and use of hormonal therapy.
• No baseline testing of cognitive function was conducted.
• The study lacked a control group.
• There were significant differences between groups in overall quality-of-life, anxiety, and depression scores.
• The selection of the delayed 12–30 month time frame may not have been the ideal time for assessment of the impact of erythropoietin on cognitive function.
• HSCS has not been shown to be a very sensitive test for detecting subtle cognitive impairments in the sample population.