Morean, D.F., O'Dwyer, L., & Cherney, L.R. (2015). Therapies for cognitive deficits associated with chemotherapy for breast cancer: A systematic review of objective outcomes. Archives of Physical Medicine and Rehabilitation, 96, 1880–1897.

DOI Link

doi: 10.1016/j.apmr.2015.05.012

Purpose

STUDY PURPOSE: To evaluate the effectiveness of interventions for objectively measured cognitive impairments in women with breast cancer who received chemotherapy

TYPE OF STUDY: Systematic review

Search Strategy

DATABASES USED: CINAHL, Cochrane, EMBASE, PsycINFO, and PubMed

KEYWORDS: Breast cancer, chemobrain, chemofog, chemotherapy, and several terms related to cognition and language deficits; appendix 1 described an extensive list of search terms and strategies that were used for PubMed and EMBASE

INCLUSION CRITERIA: Objective measurement of cognitive function; sample consisted of women with breast cancer who received or were receiving chemotherapy; experimental design (cross-sectional, longitudinal, or randomized clinical trials)

EXCLUSION CRITERIA: Case studies or series, commentaries, editorials, dissertations not published in a peer-reviewed journal, systematic reviews, and meta-analyses

Literature Evaluated

TOTAL REFERENCES RETRIEVED: 1,745

EVALUATION METHOD AND COMMENTS ON LITERATURE USED: Abstracts were screened, and 30 duplicates were eliminated (plus 14 titles without abstracts). Abstracts were reviewed to validate that the studies involved women with breast cancer who were undergoing or received chemotherapy and that they had an objective neuropsychological assessment (1,556 articles excluded). The remaining articles (n = 145) were reviewed to ensure an that an intervention was administered for cognitive impairment (131 articles excluded) and that the studies met specific quality criteria as defined by the Physiotherapy Evidence Database rating scale criteria as well as criteria for treatment fidelity (two articles excluded).

Sample Characteristics

FINAL NUMBER STUDIES INCLUDED = 12
TOTAL PATIENTS INCLUDED IN REVIEW = 442
SAMPLE RANGE ACROSS STUDIES = 12–107 patients
KEY SAMPLE CHARACTERISTICS: Although education status may influence neuropsychological test results, only half of the studies provided this information. Likewise, menopausal status may affect cognition, and this was only reported by two thirds of the studies.

Phase of Care and Clinical Applications

PHASE OF CARE: Late effects and survivorship

Results

Studies of pharmacologic interventions were not found to be effective in improving cognitive function. Medications reviewed included d-methylphenidate (n = 1), epoetin alfa (n = 2), and ginkgo biloba (n = 1). Evidence for nonpharmacologic interventions was mixed. No improvements in cognitive function were found with Tibetan sound meditation (n = 1). Natural restorative therapy (n = 1) improved attention only when comparing the baseline with the final 90-day evaluation (p = 0.01). Exercise (n = 1) improved attention (p = 0.019) and verbal memory (p = 0.048) but not working memory. Cognitive rehabilitation (n = 1) improved four out of six measures of information processing speed (p < 0.05) but not attention, verbal memory, or executive function. Cognitive behavioral training (n = 2) improved verbal memory (p < 0.05) in both studies and was effective in improving in information processing speed when compared to baseline scores in one study (p ≤ 0.01) but not the other. Computerized cognitive training was effective in one study in improving processing speed (p = 0.009), executive function (p = 0.008), and a measure of executive function and language (p = 0.003) but not verbal memory. However, in another study, there was no difference in verbal memory or information processing speed between the intervention and control groups.

Conclusions

Nonpharmacologic interventions, especially cognitive training, may have a role for improving attention, information processing speed, and verbal memory. Exercise and computerized cognitive training may be effective for improving executive function. However, additional research validating these findings with larger sample sizes and evaluating other cognitive domains is needed. In addition, studies determining the dose or duration of interventions is required for a durable response.

Limitations

A small number of studies (n = 12) were included in the review for multiple types of interventions.
Only one study had a sample size greater than 100 (range = 12–107).
Studies of low quality were included.

Nursing Implications

These findings suggest that nonpharmacologic, not pharmacologic, interventions may be helpful in managing chemotherapy-induced cognitive impairment in patients with breast cancer. However, these findings were based on a small number of studies per intervention. Additional research validating which interventions might be useful in improving cognitive impairments in women receiving chemotherapy for breast cancer is needed.

Legacy ID

5463