Exercise intervention to improve exercise capacity and health related quality of life for patients with Non-small cell lung cancer: A systematic review

Abstract

Context

The role of exercise intervention for patients with Non-small cell lung cancer (NSCLC) has not been systematically reviewed to date.

Objective

To identify, evaluate and synthesize the evidence examining (1) the effect of exercise intervention on exercise capacity, health related quality of life (HRQoL), physical activity levels, cancer symptoms and mortality for patients with NSCLC; and (2) the safety and feasibility of exercise intervention for a population with NSCLC.

Data sources

A systematic review of articles using the electronic databases MEDLINE (1950–2010), CINAHL (1982–2010), EMBASE (1980–2010), TRIP (1997–2010), Science Direct (1994–2010), PubMed (1949–2010), Cochrane Library (2010), Expanded Academic ASAP (1994–2010), Meditext Informit (1995–2010), PEDRO (1999–2010) and DARE (2010). Additional studies were identified by manually cross referencing all full text reports and personal files were searched. No publication date restrictions were imposed.

Eligibility criteria for study selection

Randomised controlled trials (RCTs), case–control studies and case series assessing exercise intervention to improve exercise capacity, HRQoL, level of daily physical activity, cancer symptoms or mortality of patients with NSCLC were included. Only articles available in English and published in a peer reviewed journal were included.

Data extraction

A data collection form was developed by one reviewer and data extracted. Data extraction was cross checked by a second reviewer.

Results and data synthesis

16 studies on 13 unique patient groups totalling 675 patients with NSCLC met the inclusion criteria. The majority of studies were case series (n = 9) and two RCTs were included. Studies exercising participants pre-operatively reported improvements in exercise capacity but no change in HRQoL immediately post exercise intervention. Studies exercising participants post-treatment (surgery, chemotherapy or radiotherapy) demonstrated improvements in exercise capacity but conflicting results with respect to the impact on HRQoL immediately post exercise intervention. Heterogeneity among studies was observed and a meta-analysis was deemed inappropriate. PRISMA guidelines were followed in reporting this systematic review.

Conclusion

Exercise intervention for patients with NSCLC is safe before and after cancer treatment. Interventions pre-operatively or post-cancer treatment are associated with positive benefits on exercise capacity, symptoms and some domains of HRQoL. The majority of studies are small case series therefore results should be viewed with caution until larger RCTs are completed. Further research is required to establish the effect of exercise during and after cancer treatment and in the advanced stage of disease, the optimum type of exercise training and the optimum setting for delivery.

Introduction

More than 1.6 million people around the world are diagnosed with lung cancer each year [1]. This number continues to grow and it is estimated that in the year 2020, 2.2 million people will be newly diagnosed with lung cancer [1]. Lung cancer is the most prevalent type of cancer and is associated with the highest mortality [1]. Prognosis is best for those patients undergoing curative treatment particularly early in the disease process [2], [3]. Given improved screening, improved prognosis following diagnosis and the aging population, the number of people living with Non-small cell lung cancer (NSCLC) in the community will continue to grow [2], [3], [4]. Long term morbidity poses a problem for many survivors of NSCLC, as does the consequential social and economic burden from the disease [5]. Clinicians and researchers are becoming increasingly focused on interventions to improve health related quality of life (HRQoL) and lessen morbidity for patients living with NSCLC.

Patients with NSCLC experience a complex plethora of symptoms that can provoke significant distress and impair physical function [6], [7]. Symptom distress has been shown to correlate negatively with HRQoL, functional status and the ability to participate in activities of daily living (ADLs) [8], [9], [10], [11]. In addition to the disease process cancer treatments cause adverse physiological and psychological effects including exercise intolerance [12], [13], [14], [15]. Symptoms result in a vicious cycle where patients may electively decrease their physical activity levels promoting further functional decline and deconditioning [9], [10], [11]. Patients with lung cancer report poorer HRQoL and a higher prevalence of psychological distress (43%) than patients with other types of cancer [16], [17], [18]. High levels of symptom distress in patients with lung cancer have been shown to be a significant predictor of inferior survival times. For these reasons there is a growing interest in outcomes of exercise intervention in this patient group. This interest has been stimulated by more recent reports that peak oxygen consumption (VO_2peak) is a strong independent predictor of overall long term survival for people with NSCLC [19].

Despite the publication of previous narrative literature reviews [20], [21] this is the first systematic review investigating the effect of exercise intervention to improve exercise capacity and HRQoL for patients with NSCLC. PRISMA guidelines have been used in reporting this systematic review (Appendix B) [22], [23].

To identify, evaluate and synthesize the evidence examining (1) the effect of exercise intervention on exercise capacity, HRQoL, physical activity levels, cancer symptoms and mortality for patients with NSCLC; and (2) the safety and feasibility of exercise intervention for a population with NSCLC. We reviewed randomised and non-randomised controlled trials that provided an exercise intervention to patients with NSCLC.