Short-term training improves aerobic performance in lung cancer20 Oct 2016
High-intensity exercise training before surgery appears to improve aerobic performance in non-small cell lung cancer patients but it does not reduce the complications after tumor resection.
Tumor resection is the leading treatment strategy for patients with early-stage operable NSCLC. Advanced age, cancer stage, associated illnesses and impaired cardiorespiratory fitness are common predictive factors of postoperative complications and long-term survival.
CPET parameters identify the risk
Cardiopulmonary exercise testing (CPET) parameters including peak oxygen consumption (peakVo2), anaerobic threshold (AT), and peak heart rate (peakHR) as well as the 6-minute walk test (6MWT) have been shown to help discriminate between patients with low versus high risk of postoperative complications.
Exercise rehabilitation programs have been shown to increase cardiorespiratory fitness and quality of life in patients with NSCLC.
However, it is not clear how to implement exercise therapy programs into standard care and whether intensity training improves mortality and postoperative complications.
A group of Swiss investigators conducted the largest randomized controlled trial to date evaluating and comparing short-term preoperative HIIT to usual care (UC) in patients undergoing NSCLC resection.
The results of the study published in the Journal of Thoracic Oncology, the official journal of the International Association for the Study of Lung Cancer (IASLC), reported that the UC and Rehab groups were randomized and well-balanced in regards to patient characteristics.
Between October 2011 and October 2014, 151 patients with resectable lung cancer were selected and analyzed.
Patients were assigned to usual care (UC) or preoperative rehabilitation (Rehab) based on HIIT.
The time from the date of enrollment to surgery was similar in the two groups and was within the maximal waiting time of 28 days recommended by the British Thoracic Society.
Maximal cardiopulmonary exercise testing (CPET) and the 6-minute walk test (6MWT) were performed twice before surgery.
Adverse events were reported according to a modified version of the thoracic mortality and morbidity (TMM) classification system.
Short-term training benefits the aerobic performance
The primary outcome was a composite end point of postoperative morbidity (30-day mortality or any complications with TMM grade of >2).
Secondary outcomes were measured by the preoperative changes in CPET parameters, the incidence of postoperative complications with TMM grades of >2, length of stay in the post anesthesia care unit (PACU), and the rate of admission to the intensive care unit.
During the 25-day preoperative waiting period it was reported that oxygen consumption (peakVo2) and the 6-minute walk test (6MWT) increased in the Rehab group, whereas oxygen consumption (peakVo2) declined in the UC group.
The primary outcome did not differ significantly between the two groups with postoperative complications developing in 35.5% patients in the Rehab cohort and 50.6% in the UC cohort.
However, the incidence of pulmonary complications was lower in the Rehab cohort compared to the UC cohort and in particular atelectasis was significantly lower in the Rehab group as was decreased length of stay in the PACU.
The authors commented that: "Our study demonstrated the safety and effectiveness of a short-term exercise training program in improving aerobic performances in patients awaiting lung cancer surgery. However, this HIIT rehabilitation modality failed to produce significant difference in composite morbidity-mortality index compared with UC. Adequately powered randomized studies including high-risk patients and focusing on clinical outcome end points should question the benefits of preoperative rehabilitation interventions."