Moderators of Exercise Effects on Cancer-related Fatigue:A Meta-analysis of Individual Patient Data

PURPOSE: Fatigue is a common and potentially disabling symptom in patients with cancer. It can often be effectively reduced by exercise. Yet, effects of exercise interventions might differ across subgroups. We conducted a meta-analysis using individual patient data of randomized controlled trials (RCT) to investigate moderators of exercise intervention effects on cancer-related fatigue. METHODS: We used individual patient data from 31 exercise RCT worldwide, representing 4366 patients, of whom 3846 had complete fatigue data. We performed a one-step individual patient data meta-analysis, using linear mixed-effect models to analyze the effects of exercise interventions on fatigue (z score) and to identify demographic, clinical, intervention- and exercise-related moderators. Models were adjusted for baseline fatigue and included a random intercept on study level to account for clustering of patients within studies. We identified potential moderators by testing their interaction with group allocation, using a likelihood ratio test. RESULTS: Exercise interventions had statistically significant beneficial effects on fatigue (β = -0.17; 95% confidence interval [CI], -0.22 to -0.12). There was no evidence of moderation by demographic or clinical characteristics. Supervised exercise interventions had significantly larger effects on fatigue than unsupervised exercise interventions (βdifference = -0.18; 95% CI -0.28 to -0.08). Supervised interventions with a duration ≤12 wk showed larger effects on fatigue (β = -0.29; 95% CI, -0.39 to -0.20) than supervised interventions with a longer duration. CONCLUSIONS: In this individual patient data meta-analysis, we found statistically significant beneficial effects of exercise interventions on fatigue, irrespective of demographic and clinical characteristics. These findings support a role for exercise, preferably supervised exercise interventions, in clinical practice. Reasons for differential effects in duration require further exploration

Targeting exercise interventions to patients with cancer in need:An individual patient data meta-analysis

Background: Exercise effects in cancer patients often appear modest, possibly because interventions rarely target patients most in need. This study investigated the moderator effects of baseline values on the exercise outcomes of fatigue, aerobic fitness, muscle strength, quality of life (QoL), and self-reported physical function (PF) in cancer patients during and post-treatment. Methods: Individual patient data from 34 randomized exercise trials (n = 4519) were pooled. Linear mixed-effect models were used to study moderator effects of baseline values on exercise intervention outcomes and to determine whether these moderator effects differed by intervention timing (during vs post-treatment). All statistical tests were two-sided. Results: Moderator effects of baseline fatigue and PF were consistent across intervention timing, with greater effects in patients with worse fatigue (Pinteraction = .05) and worse PF (Pinteraction = .003). Moderator effects of baseline aerobic fitness, muscle strength, and QoL differed by intervention timing. During treatment, effects on aerobic fitness were greater for patients with better baseline aerobic fitness (Pinteraction = .002). Post-treatment, effects on upper (Pinteraction < .001) and lower (Pinteraction = .01) body muscle strength and QoL (Pinteraction < .001) were greater in patients with worse baseline values. Conclusion: Although exercise should be encouraged for most cancer patients during and post-treatments, targeting specific subgroups may be especially beneficial and cost effective. For fatigue and PF, interventions during and post-treatment should target patients with high fatigue and low PF. During treatment, patients experience benefit for muscle strength and QoL regardless of baseline values; however, only patients with low baseline values benefit post-treatment. For aerobic fitness, patients with low baseline values do not appear to benefit from exercise during treatment

Effects and moderators of exercise on muscle strength, muscle function and aerobic fitness in patients with cancer:A meta-analysis of individual patient data

To optimally target exercise interventions for patients with cancer, it is important to identify which patients benefit from which interventions. Design We conducted an individual patient data meta-analysis to investigate demographic, clinical, intervention-related and exercise-related moderators of exercise intervention effects on physical fitness in patients with cancer. Data sources We identified relevant studies via systematic searches in electronic databases (PubMed, Embase, PsycINFO and CINAHL). Eligibility criteria We analysed data from 28 randomised controlled trials investigating the effects of exercise on upper body muscle strength (UBMS) and lower body muscle strength (LBMS), lower body muscle function (LBMF) and aerobic fitness in adult patients with cancer. Results Exercise significantly improved UBMS (β=0.20, 95% Confidence Interval (CI) 0.14 to 0.26), LBMS (β=0.29, 95% CI 0.23 to 0.35), LBMF (β=0.16, 95% CI 0.08 to 0.24) and aerobic fitness (β=0.28, 95% CI 0.23 to 0.34), with larger effects for supervised interventions. Exercise effects on UBMS were larger during treatment, when supervised interventions included ≥3 sessions per week, when resistance exercises were included and when session duration was >60 min. Exercise effects on LBMS were larger for patients who were living alone, for supervised interventions including resistance exercise and when session duration was >60 min. Exercise effects on aerobic fitness were larger for younger patients and when supervised interventions included aerobic exercise. Conclusion Exercise interventions during and following cancer treatment had small effects on UBMS, LBMS, LBMF and aerobic fitness. Demographic, intervention-related and exercise-related characteristics including age, marital status, intervention timing, delivery mode and frequency and type and time of exercise sessions moderated the exercise effect on UBMS, LBMS and aerobic fitness.Sin financiación12.022 JCR (2019) Q1, 1/85 Sport Sciences3.712 SJR (2019) Q1, 48/2754 Medicine (miscellaneous), 1/284 Orthopedics and Sports Medicine, 1/207 Physical Therapy, Sports Therapy and Rehabilitation, 2/125 Sports ScienceNo data IDR 2019UE

Effects of physical exercise during adjuvant breast cancer treatment on physical and psychosocial dimensions of cancer-related fatigue : A meta-analysis

Cancer-related fatigue has a multidimensional nature and complaints typically increase during adjuvant treatment for breast cancer. Physical exercise might prevent or reduce cancer-related fatigue. So far, no meta-analysis has investigated the effects of physical exercise on different dimensions of fatigue. The aim of the present meta-analysis was to investigate the effects of physical exercise during adjuvant breast cancer treatment on physical and psychosocial dimensions of fatigue. We performed a systematic literature search in PubMed, Embase and the Cochrane Library in June 2015. Randomised controlled trials reporting the effects of physical exercise during adjuvant breast cancer treatment on different dimensions of fatigue were included. Pooled effects of 6 exercise programmes (including 784 patients) showed significant beneficial exercise effects on general fatigue (ES: -0.22, 95% CI -0.38; -0.05) and physical fatigue (ES: -0.35, 95% CI -0.49; -0.21). Effects on fatigue subscales 'reduced activity' (ES: -0.22, 95% CI -0.38; -0.05) and 'reduced motivation' (ES: -0.18, 95% CI -0.35; -0.01) were also in favour of physical exercise. No effects were found on cognitive and affective fatigue. Including only the supervised exercise programmes (n = 4 studies), slightly larger pooled effect estimates were found on general fatigue (ES: -0.25, 95% CI -0.47; -0.04) and physical fatigue (-0.39, 95% CI -0.56; -0.23). In conclusion, physical exercise during adjuvant breast cancer treatment has beneficial effects on general fatigue, physical fatigue, 'reduced activity' and 'reduced motivation', but did not show effects on cognitive and affective fatigue. Largest effect sizes are found for physical fatigue, suggesting that this is the fatigue dimension most sensitive to physical exercise

Physical Fitness and Chemotherapy Tolerance in Patients with Early-Stage Breast Cancer

INTRODUCTION: An optimal relative dose intensity (RDI) of adjuvant chemotherapy is associated with better survival in patients with breast cancer. Little is known about the role of physical fitness in attaining an adequate RDI in patients with early stage breast cancer. We investigated the association between pre-treatment physical fitness and RDI in this population. METHODS: We pooled individual patient data from two randomized exercise trials that studied exercise programs in early breast cancer: the PACES (n = 230) and the PACT (N = 204) study. Logistic regression models were used to evaluate the association between pre-treatment fitness and achieving an optimal RDI (≥85%). In addition, we added an interaction term to the model to explore the potential moderating effect of participating in an exercise program. RESULTS: Data were available for 419 patients (mean age at diagnosis 50.0 ± 8.6 years). In the total sample, lower pre-treatment physical fitness was associated with significantly lower odds of achieving ≥85% RDI: age-adjusted OR 0.66 [95%CI 0.46-0.94]. In patients allocated to the supervised exercise intervention during chemotherapy (n = 173), the association between pretreatment physical fitness and RDI was almost completely mitigated (OR 0.95 (95%CI 0.54-1.56)), while it was more pronounced in patients who received care as usual (n = 172, OR 0.31 (95%CI 0.13-0.63) pinteraction: 0.022). CONCLUSION: Early stage breast cancer patients with relatively lower levels of pretreatment physical fitness have lower odds of achieving an optimal dose of chemotherapy. Given that physical fitness is modifiable and our results suggest that following a moderate-to-high intensity exercise training during chemotherapy could improve treatment completion, clinicians should not refrain from referring patients to supportive exercise programs because of low fitness

Physical Fitness and Chemotherapy Tolerance in Patients with Early-Stage Breast Cancer

Introduction An optimal relative dose intensity (RDI) of adjuvant chemotherapy is associated with better survival in patients with breast cancer. Little is known about the role of physical fitness in attaining an adequate RDI in patients with early-stage breast cancer. We investigated the association between pretreatment physical fitness and RDI in this population. Methods We pooled individual patient data from two randomized exercise trials that studied exercise programs in early breast cancer: the Physical Exercise During Adjuvant Chemotherapy Effectiveness Study (n = 230) and the Physical Activity during Chemotherapy Treatment (n = 204) study. Logistic regression models were used to evaluate the association between pretreatment fitness and achieving an optimal RDI (≥85%). In addition, we added an interaction term to the model to explore the potential moderating effect of participating in an exercise program. Results Data were available for 419 patients (mean age at diagnosis, 50.0 ± 8.6 yr). In the total sample, lower pretreatment physical fitness was associated with significantly lower odds of achieving ≥85% RDI: age-adjusted odds ratio (OR) of 0.66 (95% confidence interval (CI), 0.46-0.94). In patients allocated to the supervised exercise intervention during chemotherapy (n = 173), the association between pretreatment physical fitness and RDI was almost completely mitigated (OR, 0.95 (95% CI, 0.54-1.56)), whereas it was more pronounced in patients who received care as usual (n = 172; OR, 0.31 (95% CI, 0.13-0.63); Pinteraction = 0.022). Conclusions Early-stage breast cancer patients with relatively lower levels of pretreatment physical fitness have lower odds of achieving an optimal dose of chemotherapy. Given that physical fitness is modifiable and our results suggest that following a moderate-to-high intensity exercise training during chemotherapy could improve treatment completion, clinicians should not refrain from referring patients to supportive exercise programs because of low fitness

Effects of physical exercise on markers of inflammation in breast cancer patients during adjuvant chemotherapy

PURPOSE: Exercise has been shown to reduce fatigue during cancer treatment. Hypothesized mechanisms include inflammatory pathways. Therefore, we investigated effects of exercise on markers of inflammation in breast cancer patients during adjuvant chemotherapy. METHODS: We pooled data from two randomized controlled exercise intervention trials with breast cancer patients during adjuvant chemotherapy (n = 130), which had previously shown beneficial effects of exercise on fatigue. Exercise comprised a 12-week resistance training (BEATE study) or an 18-week combined resistance and aerobic training (PACT study). Serum IL-6, IL-1ra, and the IL-6/IL-1ra ratio were quantified at baseline, mid-intervention, post-intervention, and 6-9 months post-baseline. RESULTS: Mixed effect models showed significant increases in IL-6 and IL-6/IL-1ra ratio during chemotherapy and decreases afterwards. Differences between exercise and control group were not significant at any time point. Changes in total cancer-related fatigue were significantly correlated with changes in IL-6/IL-1ra ratio (partial correlation r = 0.23) and IL-6 (r = 0.21), and changes in physical cancer-related fatigue with changes in IL-6/IL-1ra ratio (r = 0.21). CONCLUSIONS: Changes in fatigue were slightly correlated with changes in inflammatory markers, and there was a strong inflammatory response to adjuvant chemotherapy. The supervised exercise training did not counteract this increase in inflammation, suggesting that beneficial effects of exercise on fatigue during adjuvant chemotherapy for breast cancer are not essentially mediated by IL-6, IL-1ra, or the IL-6/IL-1ra ratio