ReviewExercise intervention to improve exercise capacity and health related quality of life for patients with Non-small cell lung cancer: A systematic review
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 (VO2peak) 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.
Section snippets
Protocol
No protocol had been previously published for this review.
Types of studies
This review considered quantitative study designs including randomised controlled trials (RCTs), pseudo-RCTs, cohort studies, case–control studies or case series as defined by the National Health and Medical Research Council Classification [24] and qualitative study designs. Studies without a comparative group were included because of the lack of available studies on this topic. Only studies published in a peer reviewed journal were
Study selection
The search of 11 electronic databases (Fig. 1) yielded a total 9114 studies. Cross referencing yielded a further 29 potentially relevant studies. Reports not published in English (n = 6) were excluded following the search since the librarians at The University of Melbourne and Austin Health were only able to access 50% of these studies. Assessment of title, abstract and full text resulted in 16 studies on 13 unique patient samples being selected for inclusion (Fig. 1). Prior to inclusion authors
Discussion
Studies in this review provide evidence to suggest exercise intervention for people with NSCLC either before or after treatment is associated with improvement in exercise capacity. All studies except one reported significant improvements in exercise capacity immediately following an exercise program [31], [32], [34], [35], [36], [37], [40], [43], [44], [46]. The exception to this was the study by Temel et al. [42]. In this study of exercise in patients with advanced disease the null hypothesis
Conclusion
The results of this systematic review demonstrate that patients with NSCLC can be safely exercised before and after cancer treatment. Our results suggest patients with NSCLC before and after treatment should be offered some form of exercise training. Exercise interventions pre-operatively or post-cancer treatment (surgery, chemotherapy and or radiotherapy) appear to be associated with positive benefits on exercise capacity and some domains of HRQoL and symptoms. However, because the majority of
Conflict of interest
All authors declare that the answer to the questions on our competing interest form are all No and therefore have nothing to declare. All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the C Granger corresponding author) and declare that (1) CG, CM, SB, CC, LD have support from The University of Melbourne and Austin Health for the submitted work; (2) CG, CM, SB, CC, LD have no relationships with The University of
Acknowledgements
Dr. Alfredo Cesario, Dr. Amy Litterini, Dr. G. Steven Morris for their assistance with providing additional information about their studies for this review.
Funding: There was no source of funding or sponsorship for this systematic review.
Ethics approval: Ethics approval was not required for this review.
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