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

OBJECTIVE: 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 (ß=0.20, 95% Confidence Interval (CI) 0.14 to 0.26), LBMS (ß=0.29, 95% CI 0.23 to 0.35), LBMF (ß=0.16, 95% CI 0.08 to 0.24) and aerobic fitness (ß=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.

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 quality of life and physical function in patients with cancer: An individual patient data meta-analysis of 34 RCTs.

This individual patient data meta-analysis aimed to evaluate the effects of exercise on quality of life (QoL) and physical function (PF) in patients with cancer, and to identify moderator effects of demographic (age, sex, marital status, education), clinical (body mass index, cancer type, presence of metastasis), intervention-related (intervention timing, delivery mode and duration, and type of control group), and exercise-related (exercise frequency, intensity, type, time) characteristics. Relevant published and unpublished studies were identified in September 2012 via PubMed, EMBASE, PsycINFO, and CINAHL, reference checking and personal communications. Principle investigators of all 69 eligible trials were requested to share IPD from their study. IPD from 34 randomised controlled trials (n=4519 patients) that evaluated the effects of exercise compared to a usual care, wait-list or attention control group on QoL and PF in adult patients with cancer were retrieved and pooled. Linear mixed-effect models were used to evaluate the effects of the exercise on post-intervention outcome values (z-score) adjusting for baseline values. Moderator effects were studies by testing interactions. Exercise significantly improved QoL (ß=0.15, 95%CI=0.10;0.20) and PF (ß=0.18, 95%CI=0.13;0.23). The effects were not moderated by demographic, clinical or exercise characteristics. Effects on QoL (ßdifference_in_effect=0.13, 95%CI=0.03;0.22) and PF (ßdifference_in_effect=0.10, 95%CI=0.01;0.20) were significantly larger for supervised than unsupervised interventions. In conclusion, exercise, and particularly supervised exercise, effectively improves QoL and PF in patients with cancer with different demographic and clinical characteristics during and following treatment. Although effect sizes are small, there is consistent empirical evidence to support implementation of exercise as part of cancer care.

Evaluation of an early exercise intervention after thoracotomy for non-small cell lung cancer (NSCLC), effects on quality of life, muscle strength and exercise tolerance: randomised controlled trial.

Deterioration in exercise tolerance and impairment in quality of life (QoL) are common consequences of lobectomy. This study evaluates additional exercise and strength training after lung resection on QoL, exercise tolerance and muscle strength. Fifty-three (28 male) patients attending thoracotomy for lung cancer, mean age, range 64 (32-82) years; mean pack years (SD) 31.9 (26.8); BMI 25.6 (4.2); FEV1 2.0 (0.7) l were randomised to control (usual care) or intervention (twice daily training plus usual care). After discharge the intervention group received monthly home visits and weekly telephone calls, the control group received monthly telephone calls up to 12 weeks. Assessment pre-operatively, 5 day and 12 weeks post-operatively consisted of quadriceps strength using magnetic stimulation, 6 Minute Walking Distance (6MWD) and QoL-EORTC-QLQ-LC13. QoL was unchanged over 12 weeks; 6MWD showed significant deterioration at 5 days post-operatively compared with pre-operatively, mean difference (SD)-131.6 (101.8) m and -128.0 (90.7) m in active and control groups respectively (p=0.89 between groups) which returned to pre-operative levels by 12 weeks in both groups. Quadriceps strength over the 5 day in-patient period showed a decrease of -8.3 (11.3) kg in the control group compared to increase of 4.0 (21.2) kg in the intervention group (p=0.04 between groups). Strength training after thoracotomy successfully prevented the fall in quadriceps strength seen in controls, however, there was no effect on 6MWD or QoL. 6MWD returned to pre-operative levels by 12 weeks regardless of additional support offered.