Colorectal cancer is the third most commonly diagnosed cancer worldwide. Up to half of colorectal cancer survivors report cancer-related fatigue, a debilitating and often long-term symptom impacting health-related quality of life and activity participation. . Exercise training is recommended in clinical guidelines for the management of cancer-related fatigue, but the evidence is largely from studies involving people with breast cancer or where exercise has been combined with other interventions, such as nutrition counselling. This review aimed to estimate the effects of exercise training compared to non-exercise training usual care on cancer-related fatigue in survivors of colorectal cancer, during chemotherapy and following completion of treatment.
The protocol was prospectively registered. Five databases (including PEDro and PubMed) were searched for randomised controlled trials published in English. Participants were adult colorectal cancer survivors (with survivorship defined as commencing from the time of diagnosis). The intervention was exercise training alone, defined as structured physical activity to improve or maintain physical condition. The comparator was no exercise training. Self-reported fatigue intensity was the outcome of interest. Two independent reviewers selected trials for inclusion, evaluated risk of bias and extracted data. Any disagreements were resolved by a third reviewer. Risk of bias was evaluated using the PEDro scale. Certainty of evidence was rated using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach. A meta-analysis pooled the included trials to calculate standardised mean differences, 95% confidence intervals (CI) and 95% prediction intervals (PI) to estimate the interval within which a future treatment effect would fall. One subgroup analysis was planned to compare differences in participants receiving chemotherapy compared to participants who were post-treatment.
Six trials, involving 330 participants were included (n=170 intervention, n=160 usual care). All participants had stage I-III (non-metastatic) disease. Three trials (n=156) were conducted after treatment, two during adjuvant chemotherapy (n=120) and one predominantly after treatment (n=54 of which 3.7% were receiving chemotherapy). Two trials included aerobic exercise alone, two aerobic and resistance, one trial Hatha yoga (slow pace with breathing control and stretching) and one Baduanjin Qigong (physical postures and movements, combined with mind and breathing exercises). Exercise was home-based in three trials. The program frequency ranged from 1-7 days/week and the duration was between 10-24 weeks.
Four different questionnaires were used to report cancer-related fatigue intensity meaning results were combined as standardised mean differences (SMD) and 95% confidence intervals (CI). On average, participants in the exercise training group reported reduced cancer-related fatigue compared to participants who received non-exercise training usual care (SMD=-0.29, 95% CI -0.53 to -0.06; prediction interval=−0.63; 0.04). Evidence was rated as low quality due to high risk of bias and inconsistency. Subgroup analysis showed effects during chemotherapy were moderate-large (SMD=-0.63, 95% CI -1.06 to -0.21, n=120), whereas effects were uncertain in the post-treatment phase (SMD=-0.14, 95% CI -0.43 to 0.14; prediction interval=−0.76 to 0.47, n=180). Adverse events were not reported.
Exercise training for colorectal cancer survivors during chemotherapy reduces cancer-related fatigue compared to non-exercise training usual care, although the quality of available evidence was low. Further evidence is required regarding the effects of exercise training on cancer-related fatigue in the post-treatment phase.
