Review questions
What is the benefit of exercise undertaken before surgery for lung cancer and how safe is exercise at this time?
Background
Lung surgery for non-small cell lung cancer offers people a chance of cure; however, lung surgery is associated with a risk of complications. Exercise training before surgery, through its improvement in fitness, may reduce the risk of lung complications and improve other outcomes, such as number of days people need a chest drain (a plastic tube inserted into the chest to drain off fluid or air that might be collecting after the operation), and length of hospital stay. In the 2017 version of this review, we found that exercise training was associated with a reduced risk of developing lung complications after surgery, shorter time people needed a chest drain, shorter hospital stay, and improved fitness and lung function before surgery. However, the quality of evidence was low.
Study characteristics
The evidence is current to November 2021. This review included data from 636 people in 10 studies.
Key results
Exercise training for people with lung cancer before surgery results in a large reduction (55%) in their risk of developing a lung complication after surgery compared to people who do no exercise before surgery. There were no side effects reported during exercise. Exercise before surgery is likely safe. Preoperative exercise likely reduces length of hospital stay after surgery (by about two days) and increases fitness levels upon completion of the exercise programme. The evidence is very uncertain for its effects on chest drain time.
Quality of the evidence
The overall quality of evidence ranged from very low to high, mainly because of limitations in the studies' methods, the small number of participants in the included studies and variability in the results.
Preoperative exercise training results in a large reduction in the risk of developing a postoperative pulmonary complication compared to no preoperative exercise training for people with NSCLC. It may also reduce postoperative length of hospital stay, and improve exercise capacity and lung function in people undergoing lung resection for NSCLC. The findings of this review should be interpreted with caution due to risk of bias. Research investigating the cost-effectiveness and long-term outcomes associated with preoperative exercise training in NSCLC is warranted.
Surgical resection for early-stage non-small cell lung cancer (NSCLC) offers the best chance of cure, but it is associated with a risk of postoperative pulmonary complications. It is unclear if preoperative exercise training, and the potential resultant improvement in exercise capacity, may improve postoperative outcomes. This review updates our initial 2017 systematic review.
1. To evaluate the benefits and harm of preoperative exercise training on postoperative outcomes, such as the risk of developing a postoperative pulmonary complication and the postoperative duration of intercostal catheter, in adults scheduled to undergo lung resection for NSCLC.
2. To determine the effect on length of hospital stay (and costs associated with postoperative hospital stay), fatigue, dyspnoea, exercise capacity, lung function and postoperative mortality.
We used standard, extensive Cochrane search methods. The latest search date was from 28 November 2016 to 23 November 2021.
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.
We used standard Cochrane methods. Our primary outcomes were 1. risk of developing a postoperative pulmonary complication; 2. postoperative duration of intercostal catheter and 3. safety. Our secondary outcomes were 1. postoperative length of hospital stay; 2. postintervention fatigue; 3. postintervention dyspnoea; 4. postintervention and postoperative exercise capacity; 5. postintervention lung function and 6. postoperative mortality. We used GRADE to assess the certainty of evidence for each outcome.
Along with the five RCTs included in the original version, we identified an additional five RCTs, resulting in 10 RCTs involving 636 participants. Preoperative exercise training results in a large reduction in the risk of developing a postoperative pulmonary complication compared to no preoperative exercise training (risk ratio (RR) 0.45, 95% CI 0.33 to 0.61; I2 = 0%; 9 studies, 573 participants; high-certainty evidence). The evidence is very uncertain about its effect on postoperative intercostal catheter duration (MD −2.07 days, 95% CI −4.64 to 0.49; I2 = 77%, 3 studies, 111 participants; very low-certainty evidence). Preoperative exercise training is likely safe as studies reported no adverse events. Preoperative exercise training likely results in a reduction in postoperative length of hospital stay (MD −2.24 days, 95% CI −3.64 to −0.85; I2 = 85%; 9 studies, 573 participants; moderate-certainty evidence). Preoperative exercise training likely increases postintervention exercise capacity measured by peak oxygen consumption (MD 3.36 mL/kg/minute, 95% CI 2.70 to 4.02; I2 = 0%; 2 studies, 191 participants; moderate-certainty evidence); but the evidence is very uncertain about its effect on postintervention exercise capacity measured by the 6-minute walk distance (MD 29.55 m, 95% CI 12.05 to 47.04; I2 = 90%; 6 studies, 474 participants; very low-certainty evidence). Preoperative exercise training may result in little to no effect on postintervention lung function (forced expiratory volume in one second: MD 5.87% predicted, 95% CI 4.46 to 7.28; I2 = 0%; 4 studies, 197 participants; low-certainty evidence).