Skeletal muscle depletion is associated with reduced plasma (n-3) fatty acids in non-small cell lung cancer patients

The assessment and impact of sarcopenia in lung cancer: a systematic literature review

OBJECTIVES

There is growing awareness of the relationship between sarcopenia (loss of muscle mass and function), and outcomes in cancer, making it a potential target for future therapies. In order to inform future research and practice, we undertook a systematic review of factors associated with loss of muscle mass, and the relationship between muscle function and muscle mass in lung cancer, a common condition associated with poor outcomes.

DESIGN

We conducted a computerised systematic literature search on five databases. Studies were included if they explored muscle mass as an outcome measure in patients with lung cancer, and were published in English.

SETTING

Secondary care.

PARTICIPANTS

Patients with lung cancer.

PRIMARY OUTCOME

Factors associated with loss of muscle mass and muscle function, or sarcopenia, and the clinical impact thereof in patients with lung cancer.

RESULTS

We reviewed 5726 citations, and 35 articles were selected for analysis. Sarcopenia, as defined by reduced muscle mass alone, was found to be very prevalent in patients with lung cancer, regardless of body mass index, and where present was associated with poorer functional status and overall survival. There were diverse studies exploring molecular and metabolic factors in the development of loss of muscle mass; however, the precise mechanisms that contribute to sarcopenia and cachexia remain uncertain. The effect of nutritional supplements and ATP infusions on muscle mass showed conflicting results. There are very limited data on the correlation between degree of sarcopenia and muscle function, which has a non-linear relationship in older non-cancer populations.

CONCLUSIONS

Loss of muscle mass is a significant contributor to morbidity in patients with lung cancer. Loss of muscle mass and function may predate clinically overt cachexia, underlining the importance of evaluating sarcopenia, rather than weight loss alone. Understanding this relationship and its associated factors will provide opportunities for focused intervention to improve clinical outcomes.

Polyunsaturated fatty acids and their relation with bone and muscle health in adults

Age-related bone and muscle loss are major public health problems. Investigational therapies to reduce these losses include anti-inflammatory dietary supplementations, such as polyunsaturated fatty acids (PUFA). Surprisingly, this topic has received little attention in the osteoporosis community. Recent research highlights the role of PUFA in inflammatory regulation of bone remodeling via cellular pathways. Emerging research suggests significant roles for PUFA in reducing bone and muscle loss with aging; however, findings are conflicted for PUFA and fracture risk. Limited studies suggest a relation between higher omega-3 FA and better muscle/bone in older adults. This review highlights new research since 2008 and synthesizes our current understanding of PUFA in relation to bone and muscle. Across study designs, evidence indicates that PUFA has positive effects upon bone. As data are sparse, future clinical trials and prospective studies are important to determine the long term benefits of PUFA supplementation upon bone and muscle outcomes.

Complementary therapies and integrative medicine in lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Physicians are often asked about complementary therapies by patients with cancer, and data show that the interest in and use of these therapies among patients with cancer is common. Therefore, it is important to assess the current evidence base on the benefits and risks of complementary therapies (modalities not historically used in modern Western medicine).

METHODS

A systematic literature review was carried out and recommendations were made according to the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines development methodology.

RESULTS

A large number of randomized controlled trials, systematic reviews, and meta-analyses, as well as a number of prospective cohort studies, met the predetermined inclusion criteria. These trials addressed many different issues pertaining to patients with lung cancer, such as symptoms of anxiety, mood disturbance, pain, quality of life, and treatment-related side effects. The available data cover a variety of interventions, including acupuncture, nutrition, mind-body therapies, exercise, and massage. The body of evidence supports a series of recommendations. An evidenced-based approach to modern cancer care should integrate complementary therapies with standard cancer therapies such as surgery, radiation, chemotherapy, and best supportive care measures.

CONCLUSIONS

Several complementary therapy modalities can be helpful in improving the overall care of patients with lung cancer.

Exercise and nutrition interventions in advanced lung cancer: a systematic review

In this systematic review, we sought to evaluate the effect of physical activity or nutrition interventions (or both) in adults with advanced non-small-cell lung cancer (nsclc).

METHODS

A systematic search for relevant clinical trials was conducted in 6 electronic databases, by hand searching, and by contacting key investigators. No limits were placed on study language. Information about recruitment rates, protocol adherence, patient-reported and clinical outcome measures, and study conclusions was extracted. Methodologic quality and risk of bias in each study was assessed using validated tools.

MAIN RESULTS

Six papers detailing five studies involving 203 participants met the inclusion criteria. Two of the studies were single-cohort physical activity studies (54 participants), and three were controlled nutrition studies (149 participants). All were conducted in an outpatient setting. None of the included studies combined physical activity with nutrition interventions.

CONCLUSIONS

Our systematic review suggests that exercise and nutrition interventions are not harmful and may have beneficial effects on unintentional weight loss, physical strength, and functional performance in patients with advanced nsclc. However, the observed improvements must be interpreted with caution, because findings were not consistent across the included studies. Moreover, the included studies were small and at significant risk of bias. More research is required to ascertain the optimal physical activity and nutrition interventions in advanced inoperable nsclc. Specifically, the potential benefits of combining physical activity with nutrition counselling have yet to be adequately explored in this population.

Exercise training undertaken by people within 12 months of lung resection for non-small cell lung cancer

BACKGROUND

Decreased exercise capacity and impairments in health-related quality of life (HRQoL) are common in people following lung resection for non-small cell lung cancer (NSCLC). Exercise training has been demonstrated to confer gains in exercise capacity and HRQoL for people with a range of chronic conditions, including chronic obstructive pulmonary disease and heart failure, as well as in people with cancers such as prostate and breast cancer. A programme of exercise training for people following lung resection for NSCLC may confer important gains in these outcomes. To date, evidence of its efficacy in this population is unclear.

OBJECTIVES

The primary aim of this study was to determine the effects of exercise training on exercise capacity in people following lung resection(with or without chemotherapy) for NSCLC. The secondary aims were to determine the effects on other outcomes such as HRQoL,lung function (forced expiratory volume in one second (FEV1)), peripheral muscle force, dyspnoea and fatigue as well as feelings of anxiety and depression.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 2 of 12), MEDLINE(via PubMed) (1966 to February 2013), EMBASE (via Ovid) (1974 to February 2013), SciELO (The Scientific Electronic Library Online) (1978 to February 2013) as well as PEDro (Physiotherapy Evidence Database) (1980 to February 2013).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which study participants withNSCLC, who had recently undergone lung resection,were allocated to receive either exercise training or no exercise training.

DATA COLLECTION AND ANALYSIS

Two review authors screened the studies and identified those for inclusion. Meta-analyses were performed using post-intervention datafor those studies in which no differences were reported between the exercise and control group either: (i) prior to lung resection, or(ii) following lung resection but prior to the commencement of the intervention period. Although two studies reported measures of quadriceps force on completion of the intervention period, meta-analysis was not performed on this outcome as one of the two studies demonstrated significant differences between the exercise and control group at baseline (following lung resection).

MAIN RESULTS

We identified three RCTs involving 178 participants. Three out of the seven domains included in the Cochrane Collaboration' s 'seven evidence-based domains' table were identical in their assessment across the three studies (random sequence generation, allocation concealment and blinding of participants and personnel). The domain which had the greatest variation was 'blinding of outcome assessment' where one study was rated at low risk of bias, one at unclear risk of bias and the remaining one at high risk of bias. On completion of the intervention period, exercise capacity as measured by the six-minute walk distance was statistically greater in the intervention group compared to the control group (mean difference (MD) 50.4 m; 95% confidence interval (CI) 15.4 to 85.2 m). No between-group differences were observed in HRQoL (standardised mean difference (SMD) 0.17; 95% CI -0.16 to 0.49) or FEV1 (MD-0.13 L; 95% CI -0.36 to 0.11 L). Differences in quadriceps force were not demonstrated on completion of the intervention period.

AUTHORS' CONCLUSIONS

The evidence summarised in our review suggests that exercise training may potentially increase the exercise capacity of people following lung resection for NSCLC. The findings of our systematic review should be interpreted with caution due to disparities between the studies, methodological limitations, some significant risks of bias and small sample sizes. This systematic review emphasises the need for larger RCTs..

Omega-3 fatty acids and cancers: a systematic update review of epidemiological studies

Experimental models showed consistently a modulation of carcinogenesis by omega 3 polyunsaturated fatty acids (ω3 PUFA). Fish intake is often described as part of a beneficial dietary pattern. However, observational epidemiological studies on the relationship between ω3 PUFA reported conflicting results. The objective of this systematic review is to determine whether there exists any progress in the evaluation of the causal relationship between dietary ω3 PUFA and cancers since the previous FAO/OMS expert consultation and whether it is possible to propose preventive and/or adjuvant therapeutic recommendations. Prospective and case-control observational studies published since 2007 and meeting validity criteria were considered together with RCT. Experimental studies are mentioned to provide for biological plausibility. When evaluating the level of evidence, a portfolio approach was used, weighted by a hierarchy giving higher importance to prospective studies followed by RCT if any. There is a probable level of evidence that ALA per se is neither a risk factor nor a beneficial factor with regards to cancers. Observational studies on colorectal, prostate and breast cancers only provided limited evidence suggesting a possible role of LC-ω3PUFA in cancer prevention because insufficient homogeneity of the observations. Explanation for heterogeneity might be the inherent difficulties associated with epidemiology (confounding and dietary pattern context, measurement error, level of intake, genetic polymorphism). The role of LC-ω3PUFA as adjuvant, might be considered of possible use, in view of the latest RCT on lung cancers even if RCT on other cancers still need to be undertaken.

n-3 polyunsaturated fatty acids: the potential role for supplementation in cancer

PURPOSE OF REVIEW

n-3 polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaenoic acid have been implicated as potential mediators in pathways involved in cancer cachexia. This review summarizes recent findings on the n-3 fatty acid status of patients with cancer, the effects of n-3 fatty acid supplementation on weight and lean body mass and the potential role of supplementation during antineoplastic therapy.

RECENT FINDINGS

Due to suboptimal intakes and possible metabolic disturbances, physiological concentrations of n-3 fatty acids are low in patients with cancer. Low n-3 fatty acids are associated with loss of skeletal muscle, suggesting a need for supplementation. Recent trials have shown an effect of n-3 supplementation throughout antineoplastic therapy on weight, lean body mass and treatment outcomes. Attenuation or gain of weight and lean body mass was reported and the first clinical trials of n-3 fatty acids as an adjuvant to chemotherapy treatment suggest improved efficacy and milder treatment toxicity with n-3 fatty acid supplementation.

SUMMARY

Recent evidence appears to favour providing n-3 fatty acids early in the disease trajectory, during antineoplastic therapy for preservation of muscle and also to improve treatment tolerance. Additional, larger trials are needed to define these relationships further but it appears that fish oil has broad therapeutic potential in patients with cancer.

The advantages and limitations of cross-sectional body composition analysis

PURPOSE OF REVIEW

Cross-sectional (C-S) imaging is now commonly used to measure body composition in clinical studies. This review highlights the advantages, limitations and suggested future directions for this technique.

RECENT FINDINGS

Current understanding of C-S imaging reproducibility, tissue identification and segmentation methods, comparison between imaging techniques and estimates of whole body composition using a single image are described.

SUMMARY

C-S imaging can reliably measure muscle and fat distribution and uniquely discriminate between intra-abdominal organ and muscle component of fat-free mass. It precisely tracks changes within an individual, but is less able to distinguish true differences in whole body estimates between individuals.

DHA reduces the atrophy-associated Fn14 protein in differentiated myotubes during coculture with macrophages

Macrophages are an important component of muscle where they are involved in complex processes such as repair, regeneration and hypertrophy. We recently reported that macrophage numbers increase in the muscle of obese patients, suggesting that muscle-resident macrophages could be involved in the development of muscle insulin resistance that is associated with obesity. Coculture of activated macrophages with human muscle cells impairs insulin signaling and induces atrophy signaling pathways in the human muscle cells; this is exacerbated by the addition of palmitic acid. In this study, we tested the hypothesis that docosahexaenoic acid (DHA), a polyunsaturated fatty acid that has anti-inflammatory properties, would have the opposite effect of palmitic acid on muscle-macrophage cocultures. Surprisingly, DHA did not stimulate insulin signaling in human muscle myotubes that were cocultured with fibroblasts or macrophages. However, DHA inhibited Fn14, the TNF-like weak inducer of apoptosis receptor that increases the expression of the muscle-specific ubiquitin ligase MuRF-1 (muscle ring-finger protein-1). DHA treatment also increased the apparent molecular mass of MuRF-1 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels, suggesting that DHA causes MuRF-1 to be posttranslationally modified. In conclusion, these results suggest that DHA may have a beneficial effect on muscle mass in humans by inhibiting the induction of Fn14 by infiltrating macrophages.