Preoperative exercise training for patients with non-small cell lung cancer

Surgical resection for early stage non-small cell lung cancer (NSCLC) offers the best chance of cure, but is associated with a risk of postoperative pulmonary complications (i.e. pneumonia (new infiltrate coupled with either fever (> 38º C) and purulent secretions, or fever and white cell count > 11,000), bronchopleural fistula, severe atelectasis that requires chest physiotherapy or bronchoscopy, and prolonged mechanical ventilation (> 48 hours)). It is currently unclear if preoperative exercise training, and the potential resultant improvement in exercise capacity, may also improve postoperative outcomes, such as the risk of developing postoperative pulmonary complications, the length of postoperative intercostal drainage, or the length of hospital stay.

The primary aims of this study were to determine the effect of preoperative exercise training on postoperative outcomes, such as risk of developing a postoperative pulmonary complication, and postoperative duration of intercostal catheter use in adults scheduled to undergo lung resection for NSCLC. The secondary aims of this study were to determine the effect of preoperative exercise training on length of hospital stay, fatigue, dyspnoea, exercise capacity, lung function, and postoperative mortality.

We searched CENTRAL, MEDLINE (PubMed), Embase Ovid, PEDro, and SciELO on the 28^th of November 2016.

We included randomised controlled trials (RCTs) in which study participants who were scheduled to undergo lung resection for NSCLC were allocated to receive either preoperative exercise training or no exercise training.

Two review authors independently screened the studies and selected those for inclusion. We performed meta-analyses for the outcomes: risk of developing a postoperative pulmonary complication; postoperative duration of intercostal catheter; length of hospital stay; post-intervention exercise capacity (6-minute walk distance), and post-intervention forced vital capacity (FVC). Although three studies reported post-intervention forced expiratory volume in 1 second (FEV₁), we did not perform meta-analysis on this outcome due to significant statistical heterogeneity (I² = 93%) across the studies. Data were not available for fatigue or dyspnoea. One study reported no in-hospital postoperative mortality in either the exercise or the non-exercise groups.

We identified five RCTs involving 167 participants (mean age ranged from 54 to 72.5 years; sample size ranged from 19 to 60 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 preoperative exercise training reduced the risk of developing a postoperative pulmonary complication by 67% (risk ratio (RR) 0.33, 95% CI 0.17 to 0.61). The number of days patients in the exercise group needed an intercostal catheter was lower than in the non-exercise group (mean difference (MD) -3.33 days, 95% CI -5.35 to -1.30 days; two studies); postoperative length of hospital stay was also lower in the exercise group (MD -4.24 days, 95% CI -5.43 to -3.06 days; four studies). Pooled data from two studies demonstrated that compared to the non-exercise group, post-intervention 6-minute walk distance (MD 18.23 m, 95% CI 8.50 to 27.96 m), and post-intervention FVC (MD 2.97% predicted, 95% CI 1.78 to 4.16% predicted) were higher in the exercise group.

Preoperative exercise training may reduce the risk of developing a postoperative pulmonary complication, the duration of intercostal catheter use, postoperative length of hospital stay, and improve both exercise capacity and FVC in people undergoing lung resection for NSCLC. The findings of this review should be interpreted with caution due to disparities between the studies, risk of bias, and small sample sizes. This review emphasises the need for larger RCTs.