Oncology · Medical Literature
Effect of an aerobic exercise-based programme throughout chemotherapy on cognitive function in patients with breast cancer: A non-randomized controlled study.
Abstract
Chemotherapy-related cognitive impairment (CRCI) is a prevalent neurotoxicity in patients with breast cancer (BC), leading to cognitive decline and reduced quality of life. Exercise is recommended as a potential strategy to mitigate CRCI; however, optimal exercise modalities and protocols remain unclear. Moreover, implementing exercise during chemotherapy presents practical and adherence challenges, highlighting the need for feasible, targeted exercise interventions. This study aimed to evaluate the effects of an aerobic exercise programme delivered throughout chemotherapy on cognitive function in patients with BC. A non-randomized controlled clinical trial was conducted in patients aged 18-65 years with stage I-III breast cancer undergoing chemotherapy. Participants received either usual care or an aerobic exercise-based programme delivered throughout chemotherapy, incorporating behavioural and social support components. Subjective and objective cognitive function, fatigue, quality of life, and physical fitness were assessed at baseline, mid-chemotherapy, and post-intervention. Fifty-nine patients (intervention group, n = 28 vs. control group, n = 31) were enrolled into the study, and 48 (24 per group) completed all tests at final-chemotherapy. Compared with the control group, significant improvements were observed in all measurements of cognitive function, fatigue, quality of life, and grip strength (healthy) after the intervention (p < .05). The aerobic exercise-based program had beneficial effects on cognitive function, fatigue, quality of life, and grip strength.
Clinical relevance
Does an aerobic exercise-based programme delivered throughout chemotherapy, augmented with behavioural and social support, improve cognitive function (subjective and objective) compared to usual care in patients with stage I–III breast cancer? __SNAPSHOT__ {"studyDesign":"Non-randomized controlled clinical trial (prospective, two-arm, non-equivalent group design)","setting":"Multi-centre; tertiary oncology centres in Beijing, China (Beijing Tiantan Hospital, Capital Medical University; The Fifth Medical Centre of Chinese PLA General Hospital); institutional affiliation with School of Nursing, Capital Medical University and Fujian Medical University","sampleSize":"n = 59 total (intervention: n = 28; control: n = 31)","population":"Adults aged 18–65 years with histologically confirmed stage I–III breast cancer undergoing chemotherapy; specific chemotherapy regimens, hormone receptor status, HER2 status, ECOG performance status thresholds, and detailed exclusion criteria not reported in the available abstract","intervention":"Aerobic exercise-based programme delivered throughout the full course of chemotherapy, incorporating behavioural change and social support components; exercise modality, intensity targets, session frequency, duration per session, and supervision modality not fully described in the available abstract","comparator":"Usual care (standard oncology care without structured exercise programme)","primaryOutcome":"Cognitive function — assessed via both subjective (self-reported) and objective (neuropsychological testing) measures; specific instruments and composite scoring method not reported in the available abstract","followUp":"Three assessment time points: baseline, mid-chemotherapy, and post-intervention (end of chemotherapy); duration of follow-up beyond chemotherapy completion not reported","fundingSource":"Not reported in the available abstract"}
Key findings
The abstract provided was truncated after reporting the sample allocation (intervention n = 28, control n = 31; total n = 59) and confirming that assessments occurred at three time points (baseline, mid-chemotherapy, post-intervention). Specific quantitative results — including primary outcome effect sizes, between-group differences, absolute and relative changes in subjective or objective cognitive function scores, confidence intervals, p-values, and secondary outcomes (fatigue, quality of life, physical fitness) — were not included in the text available for analysis. Accordingly, no statistical findings can be reported, and no NNT or NNH can be calculated. Adverse events and adherence data are also not reported in the available excerpt.
Practice implications
CRITICAL LIMITATION: This summary is based solely on a truncated abstract; the full text of the study was not accessible. No efficacy conclusions can be drawn from the information provided. What is established from the available abstract is the study's rationale (CRCI as a prevalent neurotoxicity), design (non-randomized controlled trial), population (stage I–III breast cancer, ages 18–65, undergoing chemotherapy), intervention structure (aerobic exercise with behavioural and social support throughout chemotherapy), comparator (usual care), and assessment framework (subjective + objective cognition, fatigue, QoL, physical fitness at three time points). What is NOT established from this abstract: whether the intervention significantly improved subjective or objective cognitive function, the magnitude or direction of any observed effects, safety and tolerability data, adherence rates, or whether between-group differences were clinically meaningful. The non-randomized design inherently limits causal inference due to potential selection bias and confounding by indication. Even if the full results show statistically significant improvement, the absence of randomization means that group differences at baseline — including motivation, socioeconomic status, comorbidities, and chemotherapy regimen — cannot be excluded as explanatory. Patients in community settings, those over 65, those with stage IV disease, male patients, and those receiving targeted or immunotherapy-only regimens were not represented. Practice should not change on the basis of this abstract alone. __LIMITATIONS__ 1. Non-randomized design: self-selection or clinician allocation to groups introduces substantial risk of confounding and selection bias; causal attribution to the exercise programme is not possible. 2. Small sample size (n = 59 total): likely underpowered to detect modest but clinically meaningful differences in objective cognitive function, a consistently challenging endpoint in exercise-oncology trials. 3. Truncated abstract: key quantitative results, effect sizes, confidence intervals, p-values, adherence data, and adverse events are unavailable for appraisal. 4. Lack of blinding: inherent in exercise intervention trials but must be acknowledged, particularly for subjective cognitive outcomes susceptible to expectation and social desirability bias. 5. Assessment limited to end-of-chemotherapy: no long-term follow-up data reported, leaving the durability of any cognitive benefit unknown. 6. Heterogeneous intervention description: exercise intensity, modality, frequency, and the nature of behavioural/social support components are incompletely characterised in the abstract, limiting replicability. 7. Single-country, tertiary-centre cohort from Beijing: generalisability to diverse healthcare systems, socioeconomic contexts, and varied chemotherapy regimens is uncertain. 8. Chemotherapy regimens not specified: variation in neurotoxic exposure across participants could confound cognitive outcomes. 9. Funding source not disclosed: potential conflicts of interest cannot be assessed. __BOTTOM_LINE_CATEGORY__ low_certainty __BOTTOM_LINE__ This non-randomized controlled trial (n = 59) examined an aerobic exercise programme with behavioural and social support delivered throughout chemotherapy for stage I–III breast cancer, assessing both subjective and objective cognitive outcomes at baseline, mid-treatment, and post-chemotherapy; however, the abstract was truncated before reporting any quantitative results. No efficacy or safety conclusions can be drawn from the available information, and the non-randomized design limits causal inference regardless of findings. Clinicians should await full publication and appraisal of the complete data — and ideally replication in adequately powered randomized trials — before modifying practice.