Exercise training for advanced lung cancer

Background Patients with advanced lung cancer have a high symptom burden, which is often complicated by coexisting conditions. These issues, combined with the indirect effects of cancer treatment, can cumulatively lead patients to continued deconditioning and low exercise capacity. This is a concern as exercise capacity is considered a measure of whole body health, and is critical in a patient's ability to participate in life activities and tolerate difficult treatments. There is evidence that exercise training improves exercise capacity and other outcomes, such as muscle force and health-related quality of life (HRQoL), in cancer survivors. However, the effectiveness of exercise training on these outcomes in people with advanced lung cancer is currently unclear. Objectives The primary aim of this review was to investigate the effects of exercise training on exercise capacity in adults with advanced lung cancer. Exercise capacity was defined as the six-minute walk distance (6MWD; in meters) measured during a six-minute walk test (6MWT; i.e. how far an individual can walk in six minutes on a flat course), or the peak oxygen uptake (i.e. VO2 peak) measured during a maximal incremental cardiopulmonary exercise test (CPET). The secondary aims were to determine the effects of exercise training on the force-generating capacity of peripheral muscles, disease-specific global HRQoL, physical functioning component of HRQoL, dyspnoea, fatigue, feelings of anxiety and depression, lung function, level of physical activity, adverse events, performance status, body weight and overall survival in adults with advanced lung cancer. Search methods We searched CENTRAL, MEDLINE (via PubMed), Embase (via Ovid), CINAHL, SPORTDiscus, PEDro, and SciELO on 7 July 2018. Selection criteria We included randomised controlled trials (RCTs) which compared exercise training versus no exercise training in adults with advanced lung cancer. Data collection and analysis Two review authors independently screened the studies and selected those for inclusion. We performed meta-analyses for the following outcomes: exercise capacity, disease-specific global HRQoL, physical functioning HRQoL, dyspnoea, fatigue, feelings of anxiety and depression, and lung function (forced expiratory volume in one second (FEV1)). Two studies reported force-generating capacity of peripheral muscles, and we presented the results narratively. Limited data were available for level of physical activity, adverse events, performance status, body weight and overall survival. Main results We identified six RCTs, involving 221 participants. The mean age of participants ranged from 59 to 70 years; the sample size ranged from 20 to 111 participants. Overall, we found that the risk of bias in the included studies was high, and the quality of evidence for all outcomes was low. Pooled data from four studies demonstrated that, on completion of the intervention period, exercise capacity (6MWD) was significantly higher in the intervention group than the control group (mean difference (MD) 63.33 m; 95% confidence interval (CI) 3.70 to 122.96). On completion of the intervention period, disease-specific global HRQoL was significantly better in the intervention group compared to the control group (standardised mean difference (SMD) 0.51; 95% CI 0.08 to 0.93). There was no significant difference between the intervention and control groups in physical functioning HRQoL (SMD 0.11; 95% CI -0.36 to 0.58), dyspnoea (SMD -0.27; 95% CI -0.64 to 0.10), fatigue (SMD 0.03; 95% CI -0.51 to 0.58), feelings of anxiety (MD -1.21 units on Hospital Anxiety and Depression Scale; 95% CI -5.88 to 3.45) and depression (SMD -1.26; 95% CI -4.68 to 2.17), and FEV1 (SMD 0.43; 95% CI -0.11 to 0.97). Authors' conclusions Exercise training may improve or avoid the decline in exercise capacity and disease-specific global HRQoL for adults with advanced lung cancer. We found no significant effects of exercise training on dyspnoea, fatigue, feelings of anxiety and depression, or lung function. The findings of this review should be viewed with caution because of the heterogeneity between studies, the small sample sizes, and the high risk of bias of included studies. Larger, high-quality RCTs are needed to confirm and expand knowledge on the effects of exercise training in this population.