Chan, R.J., McCarthy, A.L., Devenish, J., Sullivan, K.A., & Chan, A. (2015). Systematic review of pharmacologic and non-pharmacologic interventions to manage cognitive alterations after chemotherapy for breast cancer. European Journal of Cancer, 51, 437–450.

DOI Link

doi: 10.1016/j.ejca.2014.12.017

Purpose

STUDY PURPOSE: To review what is known about the effectiveness of pharmacologic and nonpharmacologic interventions for managing self-reported or objective cognitive impairment associated with chemotherapy for breast cancer

TYPE OF STUDY: Systematic review

Search Strategy

DATABASES USED: MEDLINE, EBSCOhost, CINAHL, and Cochrane CENTRAL

KEYWORDS: Extensive list of terms, including keywords relevant to the receipt of chemotherapy, randomized controlled trials (RCTs), and cognitive impairment

INCLUSION CRITERIA: Prospective RCTs of pharmacologic or nonpharmacologic interventions to manage cognitive impairment during or after chemotherapy for cancer; subjective or objective measurement of cognitive function; published in English

EXCLUSION CRITERIA: Inclusion of patients with brain tumors or metastases; inclusion of patients not receiving chemotherapy; less than half of patients in sample diagnosed with breast cancers; unpublished RCTs; letters to the editor; retrospective chart reviews

Literature Evaluated

TOTAL REFERENCES RETRIEVED: 29

EVALUATION METHOD AND COMMENTS ON LITERATURE USED: Retrieved references were assessed by type of cancer (13 removed), cognitive impairment as an outcome (two removed), and confirmation of RCT (one removed). The Cochrane Collaboration risk of bias criteria were used to evaluate the final set of studies on randomization, blinding, and outcome reporting. Although effect sizes or relative risk were calculated for individual studies, a meta-analysis was not done because of the heterogeneity of the interventions and outcome measures.

Sample Characteristics

FINAL NUMBER STUDIES INCLUDED = 13
TOTAL PATIENTS INCLUDED IN REVIEW = 1,138
SAMPLE RANGE ACROSS STUDIES = 20–210 patients
KEY SAMPLE CHARACTERISTICS: Most studies included only women with breast cancer. All participants received chemotherapy with or without radiation therapy or hormonal therapy. Most participants were aged about 55 years. The majority of studies were conducted in the United States. Most outcomes were evaluated in the short-term (i.e., less than three months).

Phase of Care and Clinical Applications

PHASE OF CARE: Late effects and survivorship

Results

Risk of bias was high in 11 studies but unclear in two studies that evaluated psychostimulants.

Pharmacologic interventions: No improvements in cognitive function were found using psychostimulants (four studies) or ginkgo biloba. Patients reported better cognitive function using epoetin alfa with doses titrated for hemoglobin levels (p < 0.05). However, a death caused by a cerebrovascular accident was noted.

Nonpharmacologic interventions: Small-group memory training improved self-reported cognitive function, and both memory and speed of processing after small-group training improved immediate and delayed recall (p < 0.05). Home-based online executive function training improved verbal function and attention (p < 0.05). Speed-feedback therapy during biking improved executive and motor function (p < 0.05). Cognitive behavioral therapy-based interventions (two studies), Tibetan sound meditation, and hatha yoga did not improve cognitive function.

Conclusions

The pharmacologic studies reviewed did not support the use of psychostimulants or ginkgo biloba to improve cognitive function after chemotherapy for breast cancer. Epoetin alfa was not recommended for practice because of safety concerns. The nonpharmacologic studies reviewed provided some evidence that cognitive training and speed-feedback therapy might improve cognitive function for breast cancer survivors.

Limitations

The risk of bias was high for most studies. Therefore, although positive results were found, well-designed, prospective RCTs need to be completed to confirm these findings. It is unclear how sustainable the positive results of the cognitive training and exercise interventions might be because follow-up was limited to less than three months.

Nursing Implications

This systematic review provided limited support for cognitive training and structured exercise to improve cognitive function after chemotherapy for breast cancer. Cognitive training is currently categorized as likely to be effective for cognitive impairment.

Legacy ID

5461