Impact of cancer cachexia on respiratory muscle function and the therapeutic potential of exercise

Definition, diagnosis, and treatment of respiratory sarcopenia

PURPOSE OF REVIEW

Skeletal muscle weakness and wasting also occurs in the respiratory muscles, called respiratory sarcopenia. Respiratory sarcopenia may lead to worse clinical indicators and outcomes. We present a novel definition and diagnostic criteria for respiratory sarcopenia, summarize recent reports on the association between respiratory sarcopenia, physical and nutritional status, and clinical outcomes, and provide suggestions for the prevention and treatment of respiratory sarcopenia.

RECENT FINDINGS

Recently, a novel definition and diagnostic criteria for respiratory sarcopenia have been prepared. Respiratory sarcopenia is defined as a condition in which there is both low respiratory muscle strength and low respiratory muscle mass. Respiratory muscle strength, respiratory muscle mass, and appendicular skeletal muscle mass are used to diagnose respiratory sarcopenia. Currently, it is challenging to definitively diagnose respiratory sarcopenia due to the difficulty in accurately determining low respiratory muscle mass. Decreased respiratory muscle strength and respiratory muscle mass are associated with lower physical and nutritional status and poorer clinical outcomes. Exercise interventions, especially respiratory muscle training, nutritional interventions, and their combinations may effectively treat respiratory sarcopenia. Preventive interventions for respiratory sarcopenia are unclear.

SUMMARY

The novel definition and diagnostic criteria will contribute to promoting the assessment and intervention of respiratory sarcopenia.

The Relationship between Exercise Capacity and Muscle Strength, Physical Activity, Fatigue and Quality of Life in Patients with Cancer Cachexia

BACKGROUND

Exercise capacity is a significant determinant of mortality for cancer patients, so knowing the possible determinants of exercise capacity will produce physical and psychological benefits for individuals with cancer cachexia.

PURPOSE

To investigate the relationship between exercise capacity on peripheric and respiratory muscle strength, physical activity, fatigue and quality of life in subjects with cancer cachexia.

METHODS

The study included 31 patients diagnosed with cancer cachexia. Functional capacity was assessed by 6-Minute Walk Test, hand grip strength and proximal muscle mass by hand dynamometer, respiratory muscle strength by the Maximum Expiratory Pressure and Maximum Inspiratory Pressure measurements, physical activity by International Physical Activity Questionnaire Short Form, fatigue by Brief Fatigue Inventory, and quality of life by EORT-QLQ-C30. The relationship between functional capacity and continuous independent variables was determined using Spearman's or Pearson's tests.

RESULTS

A strong positive correlation was observed between exercise capacity and expiratory muscle strength (r = 0.75, p < 0.001), activity level (r = 0.68, p < 0.001), and quality of life global health status (r = 0.74, p < 0.001). Conversely, a strong negative correlation was found between exercise capacity and fatigue severity (r = -0.64, p < 0.001).

CONCLUSION

Higher exercise capacity in cancer cachexia patients is linked to reduced fatigue, improved respiratory muscle strength, increased physical activity levels, and enhanced quality of life. When designing rehabilitation programs or exercise interventions for individuals with cancer cachexia, it is crucial to assess their exercise capacity and tailor the programs accordingly.

Exercise-based interventions for cancer cachexia: A systematic review of randomised and non-randomised controlled trials

Objective

Cachexia is a multifactorial syndrome characterised by involuntary weight loss and functional limitation. There is a strong theoretical rationale for the use of exercise in the management of cachexia, and evidence of benefit from exercise in general cancer patients. However, clinical studies of exercise interventions in cancer cachexia are limited. We aimed to synthesise current evidence on the delivery, acceptability, safety and outcomes of exercise interventions for adults with cancer cachexia.

Methods

We conducted a systematic review. Four databases were searched up to February 2023 for randomised (RCTs) and non-randomised (NRCTs) controlled studies. Eligibility and quality were independently assessed by two authors. Data on intervention components and structure, participant flow and adherence were tabulated. Clinical outcome data on body stature and composition, muscle strength, functional performance, and health-related quality of life were synthesised using effect direction plots.

Results

Twelve studies (9 RCTs, 3 NRCTs) involving a total of 898 patients (study range 20-374) as part of a multicomponent approach. Median programme completion was 75% (range 43%-100%) and adherence was generally high. Five adverse events were considered possibly related to an intervention, including muscle or joint pain, breathlessness on exertion. Overall, 12/16 (75%) outcomes demonstrated a positive direction of effect on body stature and composition, 8/10 (80%) on muscle strength, 14/22 (64%) on functional performance, and 3/8 (38%) on health-related quality of life. Multicomponent interventions showed more consistent effects on body stature, and resistance training interventions on muscle strength.

Conclusions

Exercise interventions appear to be safe and acceptable to people with cancer cachexia. Positive effects from exercise are more consistently observed for body stature or composition and muscle strength outcomes, than in functional capacity and health-related quality of life. The synergistic effects of exercise with other cachexia interventions, including drugs, should be examined in future robust studies.

Exercise as a Promising Agent against Cancer: Evaluating Its Anti-Cancer Molecular Mechanisms

BACKGROUND

Cancer cases are continuously increasing, while the prevalence rates of physical inactivity are also continuously increasing. Physical inactivity is a causative factor in non-communicable diseases, including cancer. However, the potential beneficial effects of exercise on cancer treatment have not received much attention so far. The aim of this study was to highlight the relationship between cancer and exercise on a molecular basis.

METHODS

Comprehensive and in-depth research was conducted in the most accurate scientific databases by using relevant and effective keywords.

RESULTS

The mechanisms by which exercise may reduce cancer risk and/or progression may include the metabolic profile of hormones, systemic inflammation reduction, insulin sensitivity increase, antioxidant capacity augmentation, the boost to the immune system, and the direct effect on the tumor. There is currently substantial evidence that the effect of exercise may predict a stronger association with cancer and could supplementarily be embedded in cancer clinical practice to improve disease progression and prognosis.

CONCLUSION

The field of this study requires interconnecting the overall knowledge of exercise physiology with cancer biology and cancer clinical oncology to provide the basis for personalized targeting strategies that can be merged with training as a component of a holistic co-treatment approach to optimize cancer healthcare.

Emerging Mechanisms of Skeletal Muscle Homeostasis and Cachexia: The SUMO Perspective

Mobility is an intrinsic feature of the animal kingdom that stimulates evolutionary processes and determines the biological success of animals. Skeletal muscle is the primary driver of voluntary movements. Besides, skeletal muscles have an immense impact on regulating glucose, amino acid, and lipid homeostasis. Muscle atrophy/wasting conditions are accompanied by a drastic effect on muscle function and disrupt steady-state muscle physiology. Cachexia is a complex multifactorial muscle wasting syndrome characterized by extreme loss of skeletal muscle mass, resulting in a dramatic decrease in life quality and reported mortality in more than 30% of patients with advanced cancers. The lack of directed treatments to prevent or relieve muscle loss indicates our inadequate knowledge of molecular mechanisms involved in muscle cell organization and the molecular etiology of cancer-induced cachexia (CIC). This review highlights the latest knowledge of regulatory mechanisms involved in maintaining muscle function and their deregulation in wasting syndromes, particularly in cachexia. Recently, protein posttranslational modification by the small ubiquitin-like modifier (SUMO) has emerged as a key regulatory mechanism of protein function with implications for different aspects of cell physiology and diseases. We also review an atypical association of SUMO-mediated pathways in this context and deliberate on potential treatment strategies to alleviate muscle atrophy.