Physical exercise improves cognitive function in patients with cancer, umbrella review finds
This umbrella review of meta-analyses examined the effect of physical exercise on cognitive function in patients with cancer, a population frequently affected by cancer-related cognitive impairment (CRCI). The review included data from 7536 patients across multiple primary studies. The specific study design was an umbrella review, which synthesizes existing meta-analyses, and the publication type was meta-analysis. The setting was not reported, and the population comprised patients with cancer of various types. The intervention was physical exercise, usually supervised 12-week programs, mostly aerobic at moderate intensity. The comparator was not reported. The primary outcome was cognitive function, assessed both by self-report and objective measures. For self-reported cognitive function, the review reported an improvement, but no specific effect size, absolute numbers, p-value, or confidence interval were provided. For objectively measured cognitive function, specifically executive function and processing speed, the review found small but significant effects, again without reporting exact effect sizes, absolute numbers, p-values, or confidence intervals. The direction of effect was beneficial for both outcomes. Safety and tolerability were not reported, including adverse events, serious adverse events, and discontinuations. The review noted several limitations: methodological heterogeneity across included studies, limited adherence to the International Cognition and Cancer Task Force (ICCTF) standards, and limited evidence certainty. Funding or conflicts of interest were not reported. Compared to prior landmark studies in this therapeutic area, this umbrella review aligns with previous research suggesting cognitive benefits from exercise, but the lack of specific effect sizes and high heterogeneity limit the strength of conclusions. Key methodological limitations include the absence of reported effect sizes and confidence intervals, which precludes quantitative synthesis, and the reliance on self-reported outcomes which may be subject to bias. Clinical implications: Physical exercise may be considered as a complementary strategy for managing CRCI, but clinicians should recognize the limited certainty of the evidence and the need for individualized exercise prescriptions. Questions remain unanswered: optimal exercise type, intensity, duration, and long-term effects are not established, and more rigorous trials adhering to ICCTF standards are needed.