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.
DOI Link
Study Purpose
The study was conducted to investigate post-hoc the potential impact of erythropoietin on cognitive function following chemotherapy for breast cancer.
Intervention Characteristics/Basic Study Process
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.
Sample Characteristics
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All participants were female and had breast cancer.
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Participants were selected from a primary study group receiving adjuvant chemotherapy.
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The number of participants was 87.
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The number of participants in the treatment group (erythropoietin arm) was 45.
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The number of participants in the control group (standard care) was 42.
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Participants spent an average of 23 months in the intervention group and 24 months in the standard-of-care group.
Setting
This multi-site study took place in Canada.
Study Design
The study was a randomized, controlled trial.
Measurement Instruments/Methods
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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
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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
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Functional Assessment of Cancer Therapy (FACT)-F for cancer-related quality of life specific to symptoms of fatigue
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Hospital Anxiety and Depression Scale (HADS) for anxiety and depression.
Results
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.
Conclusions
The study failed to demonstrate a protective effect of erythropoietin on cognitive dysfunction after chemotherapy in survivors of breast cancer.
Limitations
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The study had a small sample size, given the variability in chemotherapy regimens and use of hormonal therapy.
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No baseline testing of cognitive function was conducted.
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The study lacked a control group.
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There were significant differences between groups in overall quality-of-life, anxiety, and depression scores.
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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.
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HSCS has not been shown to be a very sensitive test for detecting subtle cognitive impairments in the sample population.