Modeling the energetic cost of cancer as a result of altered energy metabolism: implications for cachexia

A [18F]FDG PET based nomogram to predict cancer-associated cachexia and survival outcome: A multi-center study

OBJECTIVES

Cancer patients with cachexia face poor prognosis and shortened survival. Early diagnosis and accurate prognosis prediction remain challenging. This multi-center study aims to develop and externally validate a nomogram integrating [18F]fluoro-2-deoxy-D-glucose ([18F]FDG) PET findings and routine clinical biochemistry tests for predicting cancer-associated cachexia, while also assessing its potential prognostic value.

RESEARCH METHODS & PROCEDURES

A retrospective analysis of 658 cancer patients (390 in the development cohort, 268 in the validation cohort) utilized [18F]FDG PET/CT data from two centers. Logistic regression identified organ-specific standardized uptake values (SUVs) and clinical variables associated with cancer-associated cachexia. Diagnostic accuracy, discriminative ability, and clinical effectiveness were assessed using area under the curve (AUC), calibration curve, and decision curve. Nomogram predictability for overall survival was evaluated through Cox regression and Kaplan-Meier curves.

RESULTS

The combined nomogram incorporating age (odds ratio [OR] = 1.893; P = 0.012), hemoglobin (OR = 2.591; P < 0.001), maximum SUV of the liver (OR = 3.646; P < 0.001), and minimum SUV of the subcutaneous fat (OR = 5.060; P < 0.001) achieved good performance in predicting cancer-associated cachexia (AUC = 0.807/0.726, development/validation). Calibration and decision curve analyses confirmed its clinical effectiveness. Kaplan-Meier curves analysis showed that overall survival can be categorized using the combined nomogram (P < 0.001).

CONCLUSION

Combining radiological information from clinical standard [18F]FDG PET data from cancer patients with biochemical results in their routine clinical blood tests through a well-constructed nomogram enables predicting cachexia and its effect on the prognosis of cancer patients.

Emerging cancer therapies: targeting physiological networks and cellular bioelectrical differences with non-thermal systemic electromagnetic fields in the human body - a comprehensive review

A steadily increasing number of publications support the concept of physiological networks, and how cellular bioelectrical properties drive cell proliferation and cell synchronization. All cells, especially cancer cells, are known to possess characteristic electrical properties critical for physiological behavior, with major differences between normal and cancer cell counterparts. This opportunity can be explored as a novel treatment modality in Oncology. Cancer cells exhibit autonomous oscillations, deviating from normal rhythms. In this context, a shift from a static view of cellular processes is required for a better understanding of the dynamic connections between cellular metabolism, gene expression, cell signaling and membrane polarization as states in constant flux in realistic human models. In oncology, radiofrequency electromagnetic fields have produced sustained responses and improved quality of life in cancer patients with minimal side effects. This review aims to show how non-thermal systemic radiofrequency electromagnetic fields leads to promising therapeutic responses at cellular and tissue levels in humans, supporting this newly emerging cancer treatment modality with early favorable clinical experience specifically in advanced cancer.

Cancer cachexia: multilevel metabolic dysfunction

Cancer cachexia is a complex metabolic disorder marked by unintentional body weight loss or 'wasting' of body mass, driven by multiple aetiological factors operating at various levels. It is associated with many malignancies and significantly contributes to cancer-related morbidity and mortality. With emerging recognition of cancer as a systemic disease, there is increasing awareness that understanding and treatment of cancer cachexia may represent a crucial cornerstone for improved management of cancer. Here, we describe the metabolic changes contributing to body wasting in cachexia and explain how the entangled action of both tumour-derived and host-amplified processes induces these metabolic changes. We discuss energy homeostasis and possible ways that the presence of a tumour interferes with or hijacks physiological energy conservation pathways. In that context, we highlight the role played by metabolic cross-talk mechanisms in cachexia pathogenesis. Lastly, we elaborate on the challenges and opportunities in the treatment of this devastating paraneoplastic phenomenon that arise from the complex and multifaceted metabolic cross-talk mechanisms and provide a status on current and emerging therapeutic approaches.

Nutritional Mechanisms of Cancer Cachexia

Cancer cachexia is a complex systemic wasting syndrome. Nutritional mechanisms that span energy intake, nutrient metabolism, body composition, and energy balance may be impacted by, and may contribute to, the development of cachexia. To date, clinical management of cachexia remains elusive. Leaning on discoveries and novel methodologies from other fields of research may bolster new breakthroughs that improve nutritional management and clinical outcomes. Characteristics that compare and contrast cachexia and obesity may reveal opportunities for cachexia research to adopt methodology from the well-established field of obesity research. This review outlines the known nutritional mechanisms and gaps in the knowledge surrounding cancer cachexia. In parallel, we present how obesity may be a different side of the same coin and how obesity research has tackled similar research questions. We present insights into how cachexia research may utilize nutritional methodology to expand our understanding of cachexia to improve definitions and clinical care in future directions for the field.

Autophagic signaling promotes systems-wide remodeling in skeletal muscle upon oncometabolic stress by D2-HG

OBJECTIVES

Cachexia is a metabolic disorder and comorbidity with cancer and heart failure. The syndrome impacts more than thirty million people worldwide, accounting for 20% of all cancer deaths. In acute myeloid leukemia, somatic mutations of the metabolic enzyme isocitrate dehydrogenase 1 and 2 cause the production of the oncometabolite D2-hydroxyglutarate (D2-HG). Increased production of D2-HG is associated with heart and skeletal muscle atrophy, but the mechanistic links between metabolic and proteomic remodeling remain poorly understood. Therefore, we assessed how oncometabolic stress by D2-HG activates autophagy and drives skeletal muscle loss.

METHODS

We quantified genomic, metabolomic, and proteomic changes in cultured skeletal muscle cells and mouse models of IDH-mutant leukemia using RNA sequencing, mass spectrometry, and computational modeling.

RESULTS

D2-HG impairs NADH redox homeostasis in myotubes. Increased NAD+ levels drive activation of nuclear deacetylase Sirt1, which causes deacetylation and activation of LC3, a key regulator of autophagy. Using LC3 mutants, we confirm that deacetylation of LC3 by Sirt1 shifts its distribution from the nucleus into the cytosol, where it can undergo lipidation at pre-autophagic membranes. Sirt1 silencing or p300 overexpression attenuated autophagy activation in myotubes. In vivo, we identified increased muscle atrophy and reduced grip strength in response to D2-HG in male vs. female mice. In male mice, glycolytic intermediates accumulated, and protein expression of oxidative phosphorylation machinery was reduced. In contrast, female animals upregulated the same proteins, attenuating the phenotype in vivo. Network modeling and machine learning algorithms allowed us to identify candidate proteins essential for regulating oncometabolic adaptation in mouse skeletal muscle.

CONCLUSIONS

Our multi-omics approach exposes new metabolic vulnerabilities in response to D2-HG in skeletal muscle and provides a conceptual framework for identifying therapeutic targets in cachexia.

Restoring Skeletal Muscle Health through Exercise in Breast Cancer Patients and after Receiving Chemotherapy

Breast cancer (BC) stands out as the most commonly type of cancer diagnosed in women worldwide, and chemotherapy, a key component of treatment, exacerbates cancer-induced skeletal muscle wasting, contributing to adverse health outcomes. Notably, the impact of chemotherapy on skeletal muscle seems to surpass that of the cancer itself, with inflammation identified as a common trigger for muscle wasting in both contexts. In skeletal muscle, pro-inflammatory cytokines modulate pathways crucial for the delicate balance between protein synthesis and breakdown, as well as satellite cell activation and myonuclear accretion. Physical exercise consistently emerges as a crucial therapeutic strategy to counteract cancer and chemotherapy-induced muscle wasting, ultimately enhancing patients' quality of life. However, a "one size fits all" approach does not apply to the prescription of exercise for BC patients, with factors such as age, menopause and comorbidities influencing the response to exercise. Hence, tailored exercise regimens, considering factors such as duration, frequency, intensity, and type, are essential to maximize efficacy in mitigating muscle wasting and improving disease outcomes. Despite the well-established anti-inflammatory role of aerobic exercise, resistance exercise proves equally or more beneficial in terms of mass and strength gain, as well as enhancing quality of life. This review comprehensively explores the molecular pathways affected by distinct exercise regimens in the skeletal muscle of cancer patients during chemotherapy, providing critical insights for precise exercise implementation to prevent skeletal muscle wasting.

Longitudinal Muscle Biopsies Reveal Inter- and Intra-Subject Variability in Cancer Cachexia: Paving the Way for Biopsy-Guided Tailored Treatment

In the rapidly evolving landscape of cancer cachexia research, the development and refinement of diagnostic and predictive biomarkers constitute an ongoing challenge. This study aims to introduce longitudinal muscle biopsies as a potential framework for disease monitoring and treatment. The initial feasibility and safety assessment was performed for healthy mice and rats that received two consecutive muscle biopsies. The assessment was performed by utilizing three different tools. Subsequently, the protocol was also applied in leiomyosarcoma tumor-bearing rats. Longitudinal muscle biopsies proved to be a safe and feasible technique, especially in rat models. The application of this protocol to tumor-bearing rats further affirmed its tolerability and feasibility, while microscopic evaluation of the biopsies demonstrated varying levels of muscle atrophy with or without leukocyte infiltration. In this tumor model, sequential muscle biopsies confirmed the variability of the cancer cachexia evolution among subjects and at different time-points. Despite the abundance of promising cancer cachexia data during the past decade, the full potential of muscle biopsies is not being leveraged. Sequential muscle biopsies throughout the disease course represent a feasible and safe tool that can be utilized to guide precision treatment and monitor the response in cancer cachexia research.

The effects of chemotherapy on resting energy expenditure, body composition, and cancer-related fatigue in women with breast cancer: a prospective cohort study

BACKGROUND

Breast cancer (BC) is the most prevalent tumor in women. Improvements in treatment led to declined mortality, resulting in more survivors living with cancer- or therapy-induced comorbidities. In this study, we investigated the impact of neoplasia and chemotherapy on resting energy expenditure (REE) and body composition, in relation to cancer-related fatigue. Inflammatory parameters were checked as possible explanation for changes in REE.

METHODS

Fifty-six women participated: 20 women with BC and 36 healthy controls. Patients were assessed at baseline (T0) and follow-up (T1) after 12 weeks of chemotherapy. Controls were measured once. REE was assessed with indirect calorimetry: body composition (body weight, fat mass, fat-free mass) by air plethysmography. The multidimensional fatigue index (MFI-20) was used to analyze fatigue. Baseline measurements of patients were compared to results of the healthy controls with the independent-samples T-test. The paired-samples T-test investigated the effects of chemotherapy from T0 to T1. A Pearson correlation analysis was conducted between REE, body composition, and fatigue and between REE, body composition, and inflammatory parameters. A linear regression analysis was fitted to estimate the contribution of the significantly correlated parameters. The measured REE at T0 and T1 was compared to the predicted REE to analyze the clinical use of the latter.

RESULTS

At baseline, patients with BC had significantly higher REE in the absence of differences in body composition. From baseline to T1, REE and body weight did not change. In contrast, fat-free mass declined significantly with concordant increase in fat mass. Fatigue deteriorated significantly. C-reactive protein at baseline predicted the change in energy expenditure. Predicted REE significantly underestimated measured REE.

CONCLUSIONS

Women with BC have higher REE in the tumor-bearing state compared to healthy controls. Chemotherapy does not affect REE but alters body composition. Predictive equations are invalid in the BC population. Results of our study can be used to implement personalized nutritional interventions to support energy expenditure and body composition and minimize long-term comorbidities.

Energy Expenditure in Upper Gastrointestinal Cancers: a Scoping Review

Malnutrition is prevalent in people with upper gastrointestinal (GI) cancers and is associated with shorter survival and poor quality of life. In order to effectively prevent or treat malnutrition, nutrition interventions must ensure appropriate energy provision to meet daily metabolic demands. In practice, the energy needs of people with cancer are frequently estimated from predictive equations which are not cancer-specific and are demonstrated to be inaccurate in this population. The purpose of this scoping review was to synthesize the existing evidence regarding energy expenditure in people with upper GI cancer. Three databases (Ovid MEDLINE, Embase via Ovid, CINAHL plus) were systematically searched to identify studies reporting on resting energy expenditure using indirect calorimetry and total energy expenditure using doubly labeled water (DLW) in adults with any stage of upper GI cancer at any point from diagnosis. A total of 57 original research studies involving 2,125 individuals with cancer of the esophagus, stomach, pancreas, biliary tract, or liver were eligible for inclusion. All studies used indirect calorimetry, and one study used DLW to measure energy expenditure, which was reported unadjusted in 42 studies, adjusted for body weight in 32 studies, and adjusted for fat-free mass in 13 studies. Energy expenditure in upper GI cancer was compared with noncancer controls in 19 studies and measured compared with predicted energy expenditure reported in 31 studies. There was heterogeneity in study design and in reporting of important clinical characteristics between studies. There was also substantial variation in energy expenditure between studies and within and between cancer types. Given this heterogeneity and known inaccuracies of predictive equations in patients with cancer, energy expenditure should be measured in practice wherever feasible. Additional research in cohorts defined by cancer type, stage, and treatment is needed to further characterize energy expenditure in upper GI cancer.

Tumor Cytokine-Induced Hepatic Gluconeogenesis Contributes to Cancer Cachexia: Insights from Full Body Single Nuclei Sequencing

A primary cause of death in cancer patients is cachexia, a wasting syndrome attributed to tumor-induced metabolic dysregulation. Despite the major impact of cachexia on the treatment, quality of life, and survival of cancer patients, relatively little is known about the underlying pathogenic mechanisms. Hyperglycemia detected in glucose tolerance test is one of the earliest metabolic abnormalities observed in cancer patients; however, the pathogenesis by which tumors influence blood sugar levels remains poorly understood. Here, utilizing a Drosophila model, we demonstrate that the tumor secreted interleukin-like cytokine Upd3 induces fat body expression of Pepck1 and Pdk, two key regulatory enzymes of gluconeogenesis, contributing to hyperglycemia. Our data further indicate a conserved regulation of these genes by IL-6/JAK-STAT signaling in mouse models. Importantly, in both fly and mouse cancer cachexia models, elevated gluconeogenesis gene levels are associated with poor prognosis. Altogether, our study uncovers a conserved role of Upd3/IL-6/JAK-STAT signaling in inducing tumor-associated hyperglycemia, which provides insights into the pathogenesis of IL-6 signaling in cancer cachexia.

Abnormal [18F]FDG uptake in liver and adipose tissue: a potential imaging biomarker for cancer-associated cachexia

OBJECTIVES

This study aims to investigate and develop imaging biomarkers for the diagnosis of cancer-associated cachexia based on the organ and tissue-specific abnormal metabolisms measured by fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) PET/CT.

METHODS

FDG PET/CT data from 390 cancer patients were analyzed retrospectively. Patients were divided into a development cohort and a validation cohort. Cachexia was defined as weight loss > 5% in 6 months or BMI < 20 and weight loss > 2%. According to the above definitions, patients were divided into cachexia and non-cachexia groups. Results of the clinical laboratory tests for metabolic levels and organ and tissue-specific FDG uptake obtained from the cachexia and non-cachexia groups were compared statistically. Logistic regression analysis was performed to identify independent variables associated with cachexia in the development cohort for generating the regression model. The performance of the model was tested using the data from a validation cohort and evaluated by area under the receiver operating characteristic curve (AUC).

RESULTS

Based on the data from the development cohort of 286 patients and a validation cohort of 104 patients, it is found that age, white blood cell count, peak standardized uptake value (SUV) of the liver, and minimum SUV of lean body mass of visceral fat and subcutaneous fat were independently associated with cachexia. The model incorporating these variables reached an AUC of 0.777 (95% confidence interval (CI): 0.721, 0.833) in the development cohort and an AUC of 0.729 (95% CI: 0.629, 0.829) in the validation cohort.

CONCLUSION

Organ and tissue-specific abnormal glucose metabolism as measured by PET/CT can be used as a biomarker for cancer-associated cachexia.

KEY POINTS

• Patients with cancer-associated cachexia have reduced FDG uptake in the liver and increased FDG uptake in visceral fat and subcutaneous fat. • FDG uptake of the liver, visceral fat, and subcutaneous fat can be independent risk factors for identifying cancer-associated cachexia. • Cancer-associated cachexia can be classified using the model that incorporates age, white blood cell count, FDG uptake of the liver, and visceral and subcutaneous fat can diagnose with an AUC of 0.729.

Deciphering the Molecular Mechanism of Yifei-Sanjie Pill in Cancer-Related Fatigue

Background

The incidence of cancer-related fatigue (CRF) is increasing, but its lack of clear pathogenesis makes its prevention and treatment difficult. Therefore, it is of great significance to clarify the pathogenesis of CRF and find effective methods to treat it.

Methods

The CRF model was established by intraperitoneal injection of LLC cells in ICR mice to explore the pathogenesis of CRF and verify the therapeutic effect of the Yifei-Sanjie pill (YFSJ). The active components of YFSJ were found by LC/MS, the in vitro inflammatory infiltration model of skeletal muscle was constructed by TNF-α and C2C12 myoblasts, and the results of in vivo experiments were verified by this model.

Results

Behavioral analysis results showed that YFSJ alleviated CRF; histological examination results showed that YFSJ could reverse the tumor microenvironment leading to skeletal muscle injury; ELISA and RNA-seq results showed that the occurrence of CRF and the therapeutic effect of YFSJ were closely related to the tumor inflammatory microenvironment; IHC and WB results showed that the occurrence of CRF and the therapeutic effect of YFSJ were closely related to the Stat3-related signaling pathway and autophagy.

Conclusions

YFSJ can reduce the level of inflammation in the tumor microenvironment in vivo, inhibit the abnormal activation of the Stat3/HIF-1α/BNIP3 signaling pathway induced by tumor-related inflammation, thereby inhibiting the overactivation of mitophagy in skeletal muscle, and finally alleviate CRF. Quercetin, one of the components of YFSJ, plays an important role in inhibiting the phosphorylation activation of Stat3.

Coronary conductance in the normal development of sheep during the perinatal period

Birth is associated with substantial shifts in cardiovascular physiology. Little is known about coronary vascular adaptations during this period. We used fetal and neonatal lambs to measure coronary function at late gestation (92% of term) and shortly after birth (5-6 days postnatal age). In each animal we measured unanesthetized myocardial perfusion and oxygen delivery using a circumflex artery flow probe. We used inflatable occluders and adenosine to determine coronary conductance and flow reserve. In a subset of animals, we used myocardial contrast echocardiography (MCE, anesthetized) to assess its utility as a tool for studying changes in regional myocardial perfusion in normal development. Separate age-matched animals were instrumented with aortic and coronary sinus sampling catheters to determine myocardial oxygen extraction (unanesthetized). With an average of 17 days of developmental time separating our neonatal and fetal cohorts we found that heart-to-body weight ratio was significantly greater in neonates than fetuses. In resting animals, we found significant decreases in weight-normalized perfusion of, and oxygen delivery to, neonatal relative to fetal myocardium. Similar results were seen when measuring baseline MCE-derived perfusion. Pressure-flow relationship studies revealed lower baseline and maximal coronary conductance in neonates than fetuses, with similar coronary flow reserve between groups. There was greater oxygen extraction in neonates than fetuses. Combined analysis of oxygen extraction with coronary flow suggested greater oxygen consumption by the fetal than neonatal myocardium. We conclude that, during the immediate perinatal period, cardiac growth outpaces coronary microvascular growth resulting in lower capacity for microvascular perfusion in the early neonate.

Pathological features of tissues and cell populations during cancer cachexia

Cancers remain among the most devastating diseases in the human population in spite of considerable advances in limiting their impact on lifespan and healthspan. The multifactorial nature of cancers, as well as the number of tissues and organs that are affected, have exposed a considerable diversity in mechanistic features that are reflected in the wide array of therapeutic strategies that have been adopted. Cachexia is manifested in a number of diseases ranging from cancers to diabetes and ageing. In the context of cancers, a majority of patients experience cachexia and succumb to death due to the indirect effects of tumorigenesis that drain the energy reserves of different organs. Considerable information is available on the pathophysiological features of cancer cachexia, however limited knowledge has been acquired on the resident stem cell populations, and their function in the context of these diseases. Here we review current knowledge on cancer cachexia and focus on how tissues and their resident stem and progenitor cell populations are individually affected.

Cancer cachexia: Pathophysiology and association with cancer-related pain

Cachexia is a syndrome of unintentional body weight loss and muscle wasting occurring in 30% of all cancer patients. Patients with cancers most commonly leading to brain metastases have a risk for cachexia development between 20 and 80%. Cachexia causes severe weakness and fatigue and negatively impacts quality and length of life. The negative energy balance in cachectic patients is most often caused by a combination of increased energy expenditure and decreased energy intake. Basal metabolic rate may be elevated due to tumor secreted factors and a systemic inflammatory response leading to inefficiency in energy production pathways and increased energy demand by the tumor and host tissues. A growing body of research explores physiological and molecular mechanisms of metabolic dysregulation in cachexia. However, decreased energy intake and physical functioning also remain important contributors to cachexia pathogenesis. Pain associated with metastatic malignancy is significantly associated with inflammation, thus making inflammation a common link between cancer pain and cachexia. Pain may also influence appetite and food intake and exacerbate fatigue and functional decline, potentially contributing to cachexia severity. Cancer pain and cachexia often occur simultaneously; however, causal relationships remain to be established. Appropriate assessment and treatment of pain in advanced cancer patients may positively impact nutrition status and physical functioning, slowing the progression of cachexia and improving quality and length of life for patients.

Utilizing Computed Tomography to Analyze the Morphomic Change between Patients with Localized and Metastatic Renal Cell Carcinoma: Body Composition Varies According to Cancer Stage

Background: This study aimed to elucidate the change of body composition in different clinical stages of renal cell carcinoma (RCC) by analyzing computed tomography (CT) images. Methods: We enrolled patients diagnosed with RCC in a tertiary medical center who did not mention body weight loss or symptoms of cachexia. We grouped patients into those with localized RCC and those with metastatic RCC. Analyses of the volume of skeletal muscles tissue (SMT), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) calculated based on CT images were performed and included subgroup analyses by sex and age. The correlation between tumor size and body composition in localized RCC was also examined. Results: A total of 188 patients were enrolled in this study. There was significantly lower VAT (p = 0.015) in the metastatic group than in the localized group. SAT, body weight, and body mass index (BMI) were not significantly different between these two groups. In the subgroup analysis, a significant difference in SMT and VAT was noted in the male and younger subgroups but not in the female and older subgroups. Regarding primary tumor size in localized RCC, VAT was significantly higher in patients with larger tumors (p = 0.003). Conclusions: In localized RCC, VAT volume was significantly larger in those with large primary tumor size. However, the VAT was significantly lower in those with metastatic status comparing to those with localized disease. The clinical course of cancers closely correlates with body composition.

Leucine Supplementation in Cancer Cachexia: Mechanisms and a Review of the Pre-Clinical Literature

Cancer cachexia (CC) is a complex syndrome of bodily wasting and progressive functional decline. Unlike starvation, cachexia cannot be reversed by increased energy intake alone. Nonetheless, targeted nutritional support is a necessary component in multimodal syndrome management. Due to the highly catabolic nature of cancer cachexia, amino acid supplementation has been proposed. Interestingly, leucine has been found to increase protein synthesis and decrease protein degradation via mTORC1 pathway activation. Multiple pre-clinical studies have explored the impact of leucine supplementation in cachectic tumor-bearing hosts. Here, we provide an overview of leucine’s proposed modes of action to preserve lean mass in cachexia and review the current pre-clinical literature related to leucine supplementation during CC. Current research indicates that a leucine-rich diet may attenuate CC symptomology; however, these works are difficult to compare due to methodological differences. There is need for further pre-clinical work exploring leucine’s potential ability to modulate protein turnover and immune response during CC, as well as the impact of additive leucine on tumor growth.

Cardiac Remodeling in Cancer-Induced Cachexia: Functional, Structural, and Metabolic Contributors

Cancer cachexia is a syndrome of progressive weight loss and muscle wasting occurring in many advanced cancer patients. Cachexia significantly impairs quality of life and increases mortality. Cardiac atrophy and dysfunction have been observed in patients with cachexia, which may contribute to cachexia pathophysiology. However, relative to skeletal muscle, little research has been carried out to understand the mechanisms of cardiomyopathy in cachexia. Here, we review what is known clinically about the cardiac changes occurring in cachexia, followed by further discussion of underlying physiological and molecular mechanisms contributing to cachexia-induced cardiomyopathy. Impaired cardiac contractility and relaxation may be explained by a complex interplay of significant heart muscle atrophy and metabolic remodeling, including mitochondrial dysfunction. Because cardiac muscle has fundamental differences compared to skeletal muscle, understanding cardiac-specific effects of cachexia may bring light to unique therapeutic targets and ultimately improve clinical management for patients with cancer cachexia.

Tumor cell anabolism and host tissue catabolism-energetic inefficiency during cancer cachexia

Cancer-associated cachexia (CC) is a pathological condition characterized by sarcopenia, adipose tissue depletion, and progressive weight loss. CC is driven by multiple factors such as anorexia, excessive catabolism, elevated energy expenditure by growing tumor mass, and inflammatory mediators released by cancer cells and surrounding tissues. In addition, endocrine system, systemic metabolism, and central nervous system (CNS) perturbations in combination with cachexia mediators elicit exponential elevation in catabolism and reduced anabolism in skeletal muscle, adipose tissue, and cardiac muscle. At the molecular level, mechanisms of CC include inflammation, reduced protein synthesis, and lipogenesis, elevated proteolysis and lipolysis along with aggravated toxicity and complications of chemotherapy. Furthermore, CC is remarkably associated with intolerance to anti-neoplastic therapy, poor prognosis, and increased mortality with no established standard therapy. In this context, we discuss the spatio-temporal changes occurring in the various stages of CC and highlight the imbalance of host metabolism. We provide how multiple factors such as proteasomal pathways, inflammatory mediators, lipid and protein catabolism, glucocorticoids, and in-depth mechanisms of interplay between inflammatory molecules and CNS can trigger and amplify the cachectic processes. Finally, we highlight current diagnostic approaches and promising therapeutic interventions for CC.

Nutrition in Advanced Thyroid Cancer Patients

In the last decade, multikinase inhibitors (MKIs) have changed the paradigm of treatment of advanced and progressive thyroid cancer. Compared with the traditional treatment with chemotherapy and radiotherapy, these new drugs have shown a good efficacy in controlling the neoplastic disease, and also a different toxicity profile compared to traditional chemotherapy, milder but still present and involving mainly the nutritional profile. Weight loss, nausea, anorexia, stomatitis, diarrhea may be associated with malnutrition and cancer-related cachexia. The latter is characteristic of the advanced cancer stage and may be present before starting MKIs, or may develop afterwards. Adverse events with nutritional impact may cause a significant impairment of quality of life, often requiring dose reduction and sometimes drug discontinuation, but with a lower efficacy on the neoplastic disease. The aim of this paper was to discuss the role of nutritional therapy in advanced thyroid cancer and the importance of prevention, early recognition and careful management of malnutrition and cachexia during systemic therapy with MKIs.

Exercise in People With Cancer: A Spotlight on Energy Regulation and Cachexia

Exercise is increasingly becoming a standard of cancer care, with well-documented benefits for patients including improved mental wellbeing and reduced treatment-related side effects. However, important gaps in knowledge remain about how to optimise exercise prescription for people with cancer. Importantly, it remains unclear how exercise affects the progression of cancer cachexia (a wasting disease stemming from energy imbalance, and a common manifestation of advanced malignant disease), particularly once the condition has already developed. It was recently suggested that the anti-tumour effect of exercise might come from improved energetic capacity. Here, we highlight the possible effect of exercise on energetic capacity and energy regulation in the context of cancer, and how this might affect the progression of cancer cachexia. We suggest that due to the additional energy demand caused by the tumour and associated systemic inflammation, overreaching may occur more easily in people with cancer. Importantly, this could result in impaired anti-tumour immunity and/or the exacerbation of cancer cachexia. This highlights the importance of individualised exercise programs for people with cancer, with special consideration for the regulation of energy balance, ongoing monitoring and possible nutritional supplementation to support the increased energy demand caused by exercise.

Impact of Cancer Cachexia on Cardiac and Skeletal Muscle: Role of Exercise Training

Simple Summary

Cachexia is a syndrome that can be present in many patients diagnosed with cancer, especially in those with metastatic or very advanced tumors. The patient may present with weight loss, loss of muscle mass, and even cardiac dysfunction as a result of it. The aim of this review is to understand how cachexia manifests and whether physical exercise has any role in trying to prevent or reverse this syndrome in cancer patients.

Abstract

Cachexia is a multifactorial syndrome that presents with, among other characteristics, progressive loss of muscle mass and anti-cardiac remodeling effect that may lead to heart failure. This condition affects about 80% of patients with advanced cancer and contributes to worsening patients’ tolerance to anticancer treatments and to their premature death. Its pathogenesis involves an imbalance in metabolic homeostasis, with increased catabolism and inflammatory cytokines levels, leading to proteolysis and lipolysis, with insufficient food intake. A multimodal approach is indicated for patients with cachexia, with the aim of reducing the speed of muscle wasting and improving their quality of life, which may include nutritional, physical, pharmacologic, and psychological support. This review aims to outline the mechanisms of muscle loss, as well as to evaluate the current clinical evidence of the use of physical exercise in patients with cachexia.

Determining the factors affecting energy metabolism and energy requirement in cancer patients

Cancer is the second most common cause of death worldwide. It is a generic name for a large group of diseases that can affect any part of the body. Cancer affects both energy intake through the diet and the total energy expenditure (TEE) through the changes in energy metabolism, resulting in negative or positive energy balance. Determining daily energy requirement is very important in the regulation of the nutrition therapy in a cancer patients. Due to the difficulty in directly measuring the TEE, resting energy expenditure, which is the largest component of the TEE, is often used in the determination of the energy requirement. In this study, the effects of disease-specific factors such as tumor burden, inflammation, weight loss and cachexia on energy metabolism in cancer patients were investigated.

Physiologic and molecular characterization of a novel murine model of metastatic head and neck cancer cachexia

BACKGROUND

Cancer cachexia is a metabolic disorder characterized by the progressive loss of fat and lean mass that results in significant wasting, ultimately leading to reduced quality of life and increased mortality. Effective therapies for cachexia are lacking, potentially owing to the mismatch in clinically relevant models of cachexia. Specifically, cachexia observed in a clinical setting is commonly associated with advanced or late-stage cancers that are metastatic, yet pre-clinical metastatic models of cachexia are limited. Furthermore, the prevalence of cachexia in head and neck cancer patients is high, yet few pre-clinical models of head and neck cancer cachexia exist. In addition to these shortcomings, cachexia is also heterogeneous among any given cancer, whereas patients with similar disease burden may experience significantly different degrees of cachexia symptoms. In order to address these issues, we characterize a metastatic model of human papilloma virus (HPV) positive head and neck squamous cell carcinoma that recapitulates the cardinal clinical and molecular features of cancer cachexia.

METHODS

Male and female C57BL/6 mice were implanted subcutaneously with oropharyngeal squamous cell carcinoma cells stably transformed with HPV16 E6 and E7 together with hRas and luciferase (mEERL) that metastasizes to the lungs (MLM). We then robustly characterize the physiologic, behavioural, and molecular signatures during tumour development in two MLM subclones.

RESULTS

Mice injected with MLM tumour cells rapidly developed primary tumours and eventual metastatic lesions to the lungs. MLM3, but not MLM5, engrafted mice progressively lost fat and lean mass during tumour development despite the absence of anorexia (P < 0.05). Behaviourally, MLM3-implanted mice displayed decreased locomotor behaviours and impaired nest building (P < 0.05). Muscle catabolism programmes associated with cachexia, including E3 ubiquitin ligase and autophagy up-regulation, along with progressive adipose wasting and accompanying browning gene signatures, were observed. Tumour progression also corresponded with hypothalamic and peripheral organ inflammation, as well as an elevation in neutrophil-to-lymphocyte ratio (P < 0.05). Finally, we characterize the fat and lean mass sparing effects of voluntary wheel running on MLM3 cachexia (P < 0.05).

CONCLUSIONS

This syngeneic MLM3 allograft model of metastatic cancer cachexia is reliable, consistent, and readily recapitulates key clinical and molecular features and heterogeneity of cancer cachexia. Because few metastatic models of cachexia exist-even though cachexia often accompanies metastatic progression-we believe this model more accurately captures cancer cachexia observed in a clinical setting and thus is well suited for future mechanistic studies and pre-clinical therapy development for this crippling metabolic disorder.

Imaging modalities for diagnosis and monitoring of cancer cachexia

Cachexia, a multifactorial wasting syndrome, is highly prevalent among advanced-stage cancer patients. Unlike weight loss in healthy humans, the progressive loss of body weight in cancer cachexia primarily implicates lean body mass, caused by an aberrant metabolism and systemic inflammation. This may lead to disease aggravation, poorer quality of life, and increased mortality. Timely detection is, therefore, crucial, as is the careful monitoring of cancer progression, in an effort to improve management, facilitate individual treatment and minimize disease complications. A detailed analysis of body composition and tissue changes using imaging modalities—that is, computed tomography, magnetic resonance imaging, (¹⁸F) fluoro-2-deoxy-d-glucose (¹⁸FDG) PET and dual-energy X-ray absorptiometry—shows great premise for charting the course of cachexia. Quantitative and qualitative changes to adipose tissue, organs, and muscle compartments, particularly of the trunk and extremities, could present important biomarkers for phenotyping cachexia and determining its onset in patients. In this review, we present and compare the imaging techniques that have been used in the setting of cancer cachexia. Their individual limitations, drawbacks in the face of clinical routine care, and relevance in oncology are also discussed.

Experimental Drugs for Chemotherapy- and Cancer-Related Anemia

Anemia in cancer patients is a relevant condition complicating the course of the neoplastic disease. Overall, we distinguish the anemia which arises under chemotherapy as pure adverse event of the toxic effects of the drugs used, and the anemia induced by the tumour-associated inflammation, oxidative stress, and systemic metabolic changes, which can be worsened by the concomitant anticancer treatments. This more properly cancer-related anemia depends on several overlapping mechanism, including impaired erythropoiesis and functional iron deficiency, which make its treatment more difficult. Standard therapies approved and recommended for cancer anemia, as erythropoiesis-stimulating agents and intravenous iron administration, are limited to the treatment of chemotherapy-induced anemia, preferably in patients with advanced disease, in view of the still unclear effect of erythropoiesis-stimulating agents on tumour progression and survival. Outside the use of chemotherapy, there are no recommendations for the treatment of cancer-related anemia. For a more complete approach, it is fundamentally a careful evaluation of the type of anemia and iron homeostasis, markers of inflammation and changes in energy metabolism. In this way, anemia management in cancer patient would permit a tailored approach that could give major benefits. Experimental drugs targeting hepcidin and activin II receptor pathways are raising great expectations, and future clinical trials will confirm their role as remedies for cancer-related anemia. Recent evidence on the effect of integrated managements, including nutritional support, antioxidants and anti-inflammatory substances, for the treatment of cancer anemia are emerging. In this review article, we show standard, innovative, and experimental treatment used as remedy for anemia in cancer patients.

Cancer-Mediated Muscle Cachexia: Etiology and Clinical Management

Muscle cachexia has a major detrimental impact on cancer patients, being responsible for 30% of all cancer deaths. It is characterized by a debilitating loss in muscle mass and function, which ultimately deteriorates patients' quality of life and dampens therapeutic treatment efficacy. Muscle cachexia stems from widespread alterations in whole-body metabolism as well as immunity and neuroendocrine functions and these global defects often culminate in aberrant signaling within skeletal muscle, causing muscle protein breakdown and attendant muscle atrophy. This review summarizes recent landmark discoveries that significantly enhance our understanding of the molecular etiology of cancer-driven muscle cachexia and further discuss emerging therapeutic approaches seeking to simultaneously target those newly discovered mechanisms to efficiently curb this lethal syndrome.

Cachexia as Evidence of the Mechanisms of Resistance and Tolerance during the Evolution of Cancer Disease

During its evolution, cancer induces changes in patients’ energy metabolism that strongly affect the overall clinical state and are responsible for cancer-related cachexia syndrome. To better understand the mechanisms underlying cachexia and its metabolic derangements, research efforts should focus on the events that are driven by the immune system activation during the evolution of neoplastic disease and on the phenomena of “resistance” and “tolerance” typically involved in the human body response against stress, pathogens, or cancer. Indeed, in the case where resistance is not able to eliminate the cancer, tolerance mechanisms can utilize the symptoms of cachexia (anemia, anorexia, and fatigue) to counteract unregulated cancer growth. These notions are also sustained by the evidence that cancer cachexia may be reversible if the resistance and tolerance phases are supported by appropriate antineoplastic treatments. Accordingly, there is no doubt that anticachectic therapies have an irreplaceable role in cases of reversible cancer cachexia where, if harmoniously associated with effective antineoplastic therapies, they can contribute to preserve the quality of life and improve prognosis. Such anticachectic treatments should be based on targeting the complex immunological, inflammatory, and metabolic pathways involved in the complex pathogenesis of cachexia. Meanwhile, the role of the anticachectic therapies is very different in the stage of irreversible cachexia when the available antineoplastic treatments are not able to control the disease and the resistance mechanisms fail with the prevalence of the tolerance phenomena. At this stage, they can be useful only to improve the quality of life, allowing the patient and their family to get a better awareness of the final phases of life, thereby opening to the best spiritual remodulation of the final event, death.

Inflammation-induced cholestasis in cancer cachexia

BACKGROUND

Cancer cachexia is a debilitating metabolic syndrome contributing to cancer death. Organs other than the muscle may contribute to the pathogenesis of cancer cachexia. This work explores new mechanisms underlying hepatic alterations in cancer cachexia.

METHODS

We used transcriptomics to reveal the hepatic gene expression profile in the colon carcinoma 26 cachectic mouse model. We performed bile acid, tissue mRNA, histological, biochemical, and western blot analyses. Two interventional studies were performed using a neutralizing interleukin 6 antibody and a bile acid sequestrant, cholestyramine. Our findings were evaluated in a cohort of 94 colorectal cancer patients with or without cachexia (43/51).

RESULTS

In colon carcinoma 26 cachectic mice, we discovered alterations in five inflammatory pathways as well as in other pathways, including bile acid metabolism, fatty acid metabolism, and xenobiotic metabolism (normalized enrichment scores of -1.97, -2.16, and -1.34, respectively; all Padj < 0.05). The hepatobiliary transport system was deeply impaired in cachectic mice, leading to increased systemic and hepatic bile acid levels (+1512 ± 511.6 pmol/mg, P = 0.01) and increased hepatic inflammatory cytokines and neutrophil recruitment to the liver of cachectic mice (+43.36 ± 16.01 neutrophils per square millimetre, P = 0.001). Adaptive mechanisms were set up to counteract this bile acid accumulation by repressing bile acid synthesis and by enhancing alternative routes of basolateral bile acid efflux. Targeting bile acids using cholestyramine reduced hepatic inflammation, without affecting the hepatobiliary transporters (e.g. tumour necrosis factor α signalling via NFκB and inflammatory response pathways, normalized enrichment scores of -1.44 and -1.36, all Padj < 0.05). Reducing interleukin 6 levels counteracted the change in expression of genes involved in the hepatobiliary transport, bile acid synthesis, and inflammation. Serum bile acid levels were increased in cachectic vs. non-cachectic cancer patients (e.g. total bile acids, +5.409 ± 1.834 μM, P = 0.026) and were strongly correlated to systemic inflammation (taurochenodeoxycholic acid and C-reactive protein: ρ = 0.36, Padj = 0.017).

CONCLUSIONS

We show alterations in bile acid metabolism and hepatobiliary secretion in cancer cachexia. In this context, we demonstrate the contribution of systemic inflammation to the impairment of the hepatobiliary transport system and the role played by bile acids in the hepatic inflammation. This work paves the way to a better understanding of the role of the liver in cancer cachexia.

Altered glucose metabolism and insulin resistance in cancer-induced cachexia: a sweet poison

Cancer cachexia is a wasting disorder characterised by specific skeletal muscle and adipose tissue loss. Cancer cachexia is also driven by inflammation, altered metabolic changes such as increased energy expenditure, elevated plasma glucose, insulin resistance and excess catabolism. In cachexia, host-tumor interaction causes release of the lactate and inflammatory cytokines. Lactate released by tumor cells takes part in hepatic glucose production with the help of gluconeogenic enzymes. Thus, Cori cycle between organs and cancerous cells contributes to increased glucose production and energy expenditure. A high amount of blood glucose leads to increased production of insulin. Overproduction of insulin causes inactivation of PI3K/Akt/m-TOR pathway and finally results in insulin resistance. Insulin is involved in maintaining the vitality of organs and regulate the metabolism of glucose, protein and lipids. Insulin insensitivity decreases the uptake of glucose in the organs and results in loss of skeletal muscles and adipose tissues. However, looking into the complexity of this metabolic syndrome, it is impossible to rely on a single variable to treat patients having cancer cachexia. Hence, it becomes greater a challenge to produce a clinically effective treatment for this metabolic syndrome. Thus, the present paper aims to provide an understanding of pathogenesis and mechanism underlining the altered glucose metabolism and insulin resistance and its contribution to the progression of skeletal muscle wasting and lipolysis, providing future direction of research to develop new pharmacological treatment in cancer cachexia.

Impact of musculoskeletal degradation on cancer outcomes and strategies for management in clinical practice

The prevalence of malnutrition in patients with cancer is one of the highest of all patient groups. Weight loss (WL) is a frequent manifestation of malnutrition in cancer and several large-scale studies have reported that involuntary WL affects 50-80% of patients with cancer, with the degree of WL dependent on tumour site, type and stage of disease. The study of body composition in oncology using computed tomography has unearthed the importance of both low muscle mass (sarcopenia) and low muscle attenuation as important prognostic indications of unfavourable outcomes including poorer tolerance to chemotherapy; significant deterioration in performance status and quality of life (QoL), poorer post-operative outcomes and shortened survival. While often hidden by excess fat and high BMI, muscle abnormalities are highly prevalent in patients with cancer (ranging from 10 to 90%). Early screening to identify individuals with sarcopenia and decreased muscle quality would allow for earlier multimodal interventions to attenuate adverse body compositional changes. Multimodal therapies (combining nutritional counselling, exercise and anti-inflammatory drugs) are currently the focus of randomised trials to examine if this approach can provide a sufficient stimulus to prevent or slow the cascade of tissue wasting and if this then impacts on outcomes in a positive manner. This review will focus on the aetiology of musculoskeletal degradation in cancer; the impact of sarcopenia on chemotherapy tolerance, post-operative complications, QoL and survival; and outline current strategies for attenuation of muscle loss in clinical practice.

Exploiting common aspects of obesity and cancer cachexia for future therapeutic strategies

Obesity and cancer cachexia are diseases at opposite ends of the BMI. However, despite the apparent dichotomy, these pathologies share some common underlying mechanisms that lead to profound metabolic perturbations. Insulin resistance, adipose tissue lipolysis, skeletal muscle atrophy and systemic inflammation are key players in both diseases. Several strategies for pharmacological treatments have been employed in obesity and cancer cachexia but demonstrated only limited effects. Therefore, there is still a need to develop novel, more effective strategies. In this review we summarize existing therapies and discuss potential novel strategies that could arise by bridging common aspects between obesity and cachexia. We discuss the potential role of macrophage manipulation and the modulation of inflammation by targeting Nuclear Receptors (NRs) as potential novel therapeutic strategies.

Mathematical Model of Muscle Wasting in Cancer Cachexia

Cancer cachexia is a debilitating condition characterized by an extreme loss of skeletal muscle mass, which negatively impacts patients' quality of life, reduces their ability to sustain anti-cancer therapies, and increases the risk of mortality. Recent discoveries have identified the myostatin/activin A/ActRIIB pathway as critical to muscle wasting by inducing satellite cell quiescence and increasing muscle-specific ubiquitin ligases responsible for atrophy. Remarkably, pharmacological blockade of the ActRIIB pathway has been shown to reverse muscle wasting and prolong the survival time of tumor-bearing animals. To explore the implications of this signaling pathway and potential therapeutic targets in cachexia, we construct a novel mathematical model of muscle tissue subjected to tumor-derived cachectic factors. The model formulation tracks the intercellular interactions between cancer cell, satellite cell, and muscle cell populations. The model is parameterized by fitting to colon-26 mouse model data, and the analysis provides insight into tissue growth in healthy, cancerous, and post-cachexia treatment conditions. Model predictions suggest that cachexia fundamentally alters muscle tissue health, as measured by the stem cell ratio, and this is only partially recovered by anti-cachexia treatment. Our mathematical findings suggest that after blocking the myostatin/activin A pathway, partial recovery of cancer-induced muscle loss requires the activation and proliferation of the satellite cell compartment with a functional differentiation program.

Understanding cachexia in the context of metastatic progression

Tumours reprogram host physiology, metabolism and immune responses during cancer progression. The release of soluble factors, exosomes and metabolites from tumours leads to systemic changes in distant organs, where cancer cells metastasize and grow. These tumour-derived circulating factors also profoundly impact tissues that are rarely inhabited by metastatic cancer cells such as skeletal muscle and adipose tissue. In fact, the majority of patients with metastatic cancer develop a debilitating muscle-wasting syndrome, known as cachexia, that is associated with decreased tolerance to antineoplastic therapy, poor prognosis and accelerated death, with no approved treatments. In this Perspective, we discuss the development of cachexia in the context of metastatic progression. We briefly discuss how circulating factors either directly or indirectly promote cachexia development and examine how signals from the metastatic process can trigger and amplify this process. Finally, we highlight promising therapeutic opportunities for targeting cachexia in the context of metastatic cancers.

Cancer cachexia has many symptoms but only one cause: anoxia

During nearly 100 years of research on cancer cachexia (CC), science has been reciting the same mantra: it is a multifactorial syndrome. The aim of this paper is to show that the symptoms are many, but they have a single cause: anoxia. CC is a complex and devastating condition that affects a high proportion of advanced cancer patients. Unfortunately, it cannot be reversed by traditional nutritional support and it generally reduces survival time. It is characterized by significant weight loss, mainly from fat deposits and skeletal muscles. The occurrence of cachexia in cancer patients is usually a late phenomenon. The conundrum is why do similar patients with similar tumors, develop cachexia and others do not? Even if cachexia is mainly a metabolic dysfunction, there are other issues involved such as the activation of inflammatory responses and crosstalk between different cell types.  The exact mechanism leading to a wasting syndrome is not known, however there are some factors that are surely involved, such as anorexia with lower calorie intake, increased glycolytic flux, gluconeogenesis, increased lipolysis and severe tumor hypoxia. Based on this incomplete knowledge we put together a scheme explaining the molecular mechanisms behind cancer cachexia, and surprisingly, there is one cause that explains all of its characteristics: anoxia.  With this different view of CC we propose a treatment based on the physiopathology that leads from anoxia to the symptoms of CC.  The fundamentals of this hypothesis are based on the idea that CC is the result of anoxia causing intracellular lactic acidosis. This is a dangerous situation for cell survival which can be solved by activating energy consuming gluconeogenesis. The process is conducted by the hypoxia inducible factor-1α. This hypothesis was built by putting together pieces of evidence produced by authors working on related topics.

Cancer Cachexia and Related Metabolic Dysfunction

Cancer cachexia is a complex multifactorial syndrome marked by a continuous depletion of skeletal muscle mass associated, in some cases, with a reduction in fat mass. It is irreversible by nutritional support alone and affects up to 74% of patients with cancer-dependent on the underlying type of cancer-and is associated with physical function impairment, reduced response to cancer-related therapy, and higher mortality. Organs, like muscle, adipose tissue, and liver, play an important role in the progression of cancer cachexia by exacerbating the pro- and anti-inflammatory response initially activated by the tumor and the immune system of the host. Moreover, this metabolic dysfunction is produced by alterations in glucose, lipids, and protein metabolism that, when maintained chronically, may lead to the loss of skeletal muscle and adipose tissue. Although a couple of drugs have yielded positive results in increasing lean body mass with limited impact on physical function, a single therapy has not lead to effective treatment of this condition. Therefore, a multimodal intervention, including pharmacological agents, nutritional support, and physical exercise, may be a reasonable approach for future studies to better understand and prevent the wasting of body compartments in patients with cancer cachexia.

Advances in cancer cachexia: Intersection between affected organs, mediators, and pharmacological interventions

Advanced cancer patients exhibit cachexia, a condition characterized by a significant reduction in the body weight predominantly from loss of skeletal muscle and adipose tissue. Cachexia is one of the major causes of morbidity and mortality in cancer patients. Decreased food intake and multi-organ energy imbalance in cancer patients worsen the cachexia syndrome. Cachectic cancer patients have a low tolerance for chemo- and radiation therapies and also have a reduced quality of life. The presence of tumors and the current treatment options for cancer further exacerbate the cachexia condition, which remains an unmet medical need. The onset of cachexia involves crosstalk between different organs leading to muscle wasting. Recent advancements in understanding the molecular mechanisms of skeletal muscle atrophy/hypertrophy and adipose tissue wasting/browning provide a platform for the development of new targeted therapies. Therefore, a better understanding of this multifactorial disorder will help to improve the quality of life of cachectic patients. In this review, we summarize the metabolic mediators of cachexia, their molecular functions, affected organs especially with respect to muscle atrophy and adipose browning and then discuss advanced therapeutic approaches to cancer cachexia.

Hepatic proteome analysis reveals altered mitochondrial metabolism and suppressed acyl-CoA synthetase-1 in colon-26 tumor-induced cachexia

Cachexia is a life-threatening complication of cancer traditionally characterized by weight loss and muscle dysfunction. Cachexia, however, is a systemic disease that also involves remodeling of nonmuscle organs. The liver exerts major control over systemic metabolism, yet its role in cancer cachexia is not well understood. To advance the understanding of how the liver contributes to cancer cachexia, we used quantitative proteomics and bioinformatics to identify hepatic pathways and cellular processes dysregulated in mice with moderate and severe colon-26 tumor-induced cachexia; ~300 differentially expressed proteins identified during the induction of moderate cachexia were also differentially regulated in the transition to severe cachexia. KEGG pathway enrichment revealed representation by oxidative phosphorylation, indicating altered hepatic mitochondrial function as a common feature across cachexia severity. Glycogen catabolism was also observed in cachexic livers along with decreased pyruvate dehydrogenase protein X component (Pdhx), increased lactate dehydrogenase A chain (Ldha), and increased lactate transporter Mct1. Together this suggests altered lactate metabolism and transport in cachexic livers, which may contribute to energetically inefficient interorgan lactate cycling. Acyl-CoA synthetase-1 (ACSL1), known for activating long-chain fatty acids, was decreased in moderate and severe cachexia based on LC-MS/MS analysis and immunoblotting. ACSL1 showed strong linear relationships with percent body weight change and muscle fiber size (R² = 0.73-0.76, P < 0.01). Mitochondrial coupling efficiency, which is compromised in cachexic livers to potentially increase energy expenditure and weight loss, also showed a linear relationship with ACSL1. Findings suggest altered mitochondrial and substrate metabolism of the liver in cancer cachexia, and possible hepatic targets for intervention.

Cachexia Anorexia Syndrome and Associated Metabolic Dysfunction in Peritoneal Metastasis

Patients with peritoneal metastasis (PM) of gastrointestinal and gynecological origin present with a nutritional deficit characterized by increased resting energy expenditure (REE), loss of muscle mass, and protein catabolism. Progression of peritoneal metastasis, as with other advanced malignancies, is associated with cancer cachexia anorexia syndrome (CAS), involving poor appetite (anorexia), involuntary weight loss, and chronic inflammation. Eventual causes of mortality include dysfunctional metabolism and energy store exhaustion. Etiology of CAS in PM patients is multifactorial including tumor growth, host response, cytokine release, systemic inflammation, proteolysis, lipolysis, malignant small bowel obstruction, ascites, and gastrointestinal side effects of drug therapy (chemotherapy, opioids). Metabolic changes of CAS in PM relate more to a systemic inflammatory response than an adaptation to starvation. Metabolic reprogramming is required for cancer cells shed into the peritoneal cavity to resist anoikis (i.e., programmed cell death). Profound changes in hexokinase metabolism are needed to compensate ineffective oxidative phosphorylation in mitochondria. During the development of PM, hypoxia inducible factor-1α (HIF-1α) plays a key role in activating both aerobic and anaerobic glycolysis, increasing the uptake of glucose, lipid, and glutamine into cancer cells. HIF-1α upregulates hexokinase II, phosphoglycerate kinase 1 (PGK1), pyruvate dehydrogenase kinase (PDK), pyruvate kinase muscle isoenzyme 2 (PKM2), lactate dehydrogenase (LDH) and glucose transporters (GLUT) and promotes cytoplasmic glycolysis. HIF-1α also stimulates the utilization of glutamine and fatty acids as alternative energy substrates. Cancer cells in the peritoneal cavity interact with cancer-associated fibroblasts and adipocytes to meet metabolic demands and incorporate autophagy products for growth. Therapy of CAS in PM is challenging. Optimal nutritional intake alone including total parenteral nutrition is unable to reverse CAS. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) stabilized nutritional status in a significant proportion of PM patients. Agents targeting the mechanisms of CAS are under development.

Hypermetabolism is an independent prognostic factor of survival in metastatic non-small cell lung cancer patients

BACKGROUND & AIMS

Metastatic non-small cell lung cancer (NSCLC) is the first cause of cancer death worldwide. Increased resting energy expenditure (REE) is frequent among cancer patients and may contribute to cancer cachexia. The aim of this study was to examine the prognostic value of increased REE in metastatic NSCLC patients.

METHODS

This observational study was conducted between June 2012 and November 2017 in the outpatient unit of the oncology department of Cochin hospital, Paris. Consecutive patients with newly diagnosed stage IV NSCLC underwent measurement of REE by indirect calorimetry before treatment initiation. Uni- and multivariate analysis of overall survival (OS, Cox models) included age, sex, smoking habit, histological subtype, performance status, body mass index, weight loss, albumin and CRP levels and the ratio of measured REE to the REE predicted by the Harris Benedict formula (mREE/pREE).

RESULTS

144 patients were enrolled: mean age 64 years, 63% male, 90% non-squamous carcinoma, including 17% with ALK/EGFR alteration. In univariate analysis, tobacco consumption (p = 0.007), histo-molecular subtype (p < 10^-3), performance status (p = 0.04), weight loss (p < 10^-4), albumin (p < 10^-4), CRP (p = 0.001) and mREE/pREE ratio (>vs ≤ 120%: HR = 2.16, p < 10^-3) were significant prognostic factors of OS. Median OS were 6.1 and 17.3 months in patients with mREE/pREE ratio > and ≤120%, respectively. In multivariate analysis, histo-molecular subtype (non-squamous ALK/EGFR mutated vs squamous carcinoma: HR = 0.25, p = 0.006), weight loss (>vs ≤ 5%: HR = 1.98, p = 0.004), albumin (≥vs < 35 g/L: HR = 0.56, p = 0.02) and mREE/pREE ratio (> vs ≤120%: HR = 1.90, p = 0.004) were identified as independent prognostic factors.

CONCLUSIONS

Elevated resting energy expenditure emerges as an independent prognostic factor in metastatic NSCLC.

Profiling Determinants of Resting Energy Expenditure in Colorectal Cancer

Background: Understanding resting energy expenditure (REE) is important for determining energy requirements; REE might be altered in individuals with cancer. The objective of this study was to characterize determinants of REE in patients with stages II-IV colorectal cancer (CRC).Methods: REE was measured via indirect calorimetry in patients with newly diagnosed CRC. Computerized tomography images from medical records ascertained skeletal muscle and total adipose tissue cross-sectional areas, which were then transformed to lean soft tissue (LST) and fat mass (FM) values (in kg). Linear regression assessed determinants of REE.Results: 86 patients were included (n = 55, 64.0% male; 60 ± 12 years old; median body mass index: 27.6, interquartile range: 24.3-31.2 kg/m²), with most (n = 40) having stage III disease. Age, sex, and weight were significant predictors of REE [R² = 0.829, standard error of the estimate (SEE): 128 kcal/day, P < 0.001]. Replacing weight with LST and FM yielded a similar model, with age, sex, LST, and FM predictive of REE (R² = 0.820, SEE: 129 kcal/day, p < 0.001).Conclusion: Age, sex, weight, LST, and FM were the main contributors to REE. Further investigation of REE changes over time and its relationship to total energy expenditure, dietary intake, and clinical outcomes should be explored.

Infusion of high concentration of lactate in perfused liver, simulating in vivo hyperlactatemia, prevents the reduction of gluconeogenesis in Walker-256 tumor-bearing rats

Gluconeogenesis (GN) is increased in patients with cancer cachexia, but is reduced in liver perfusion of Walker-256 tumor-bearing cachectic rats (TB rats). The causes of these differences are unknown. We investigated the influence of circulating concentrations of lactate (NADH generator) and NADH on GN in perfused livers of TB rats. Lactate, at concentrations similar to those found on days 5 (3.0 mM), 8 (5.5 mM), and 12 (8.0 mM) of the tumor, prevented the reduction of GN from 2.0 mM lactate (lactatemia of healthy rat) in TB rats. NADH, 50 or 75 μM, but not 25 μM, increased GN from 2.0 mM lactate in TB rats to higher values than healthy rats. High concentrations of pyruvate (no NADH generator, 5.0 and 8.0 mM) did not prevent the reduction of GN from 2.0 mM pyruvate in TB rats. However, 50 or 75 μM NADH, but not 25 μM, increased GN from 2.0 mM pyruvate in TB rats to similar or higher values than healthy rats. High concentration of glutamine (NADH generator, 2.5 mM) or 50 μM NADH prevented the reduction of GN from 1 mM glutamine in TB rats. Intraperitoneal administration of pyruvate (1.0 mg/kg) or glutamine (0.5 mg/kg) similarly increased the glycemia of healthy and TB rats. In conclusion, high lactate concentration, similar to hyperlactatemia, prevented the reduction of GN in perfused livers of TB rats, an effect probably caused by the increased redox potential (NADH/NAD⁺ ). Thus, the decreased GN in livers from TB rats is due, at least in part, to the absence of simulation of in vivo hyperlactatemia in liver perfusion studies.

Determinants of change in resting energy expenditure in patients with stage III/IV colorectal cancer

BACKGROUND & AIMS

Resting energy expenditure (REE) is variable in cancer and might be influenced by changes in tumor burden, systemic inflammation, and body composition. The objective of this study was to assess REE change and the predictors of such in patients with stage III or IV colorectal cancer.

METHODS

REE was measured via indirect calorimetry and fat mass and fat-free mass (FFM) were assessed using dual X-ray absorptiometry as part of a unique analysis of two studies. C-reactive protein (CRP) was measured as an inflammatory marker. Linear regression was used to assess the determinants of REE at baseline and REE change, with days between baseline and follow-up measures included as a covariate.

RESULTS

One-hundred and nine patients were included at baseline (59.6% male; 67 ± 12 years; body mass index 24.1 ± 4.3 kg/m²); 49 had follow-up data (61.2% male; 65 ± 12 years; body mass index 25.4 ± 4.3 kg/m²), with median follow-up of 119 days (interquartile range: 113-127 days). At baseline, age, FFM, and CRP explained 68.9% of the variability in REE. A wide variability in REE change over time was observed, ranging from -156 to 370 kcal/day, or -13.0 to 15.7%/100 days. CRP change (1.7 ± 0.4 mg/L, p < 0.001) and stage (81.3 ± 38.7, p = 0.042) predicted REE change in multivariate analysis, controlling for age, FFM change, and days between visits (R²: 0.417 ± 88.2, p < 0.001).

CONCLUSIONS

Age, FFM, and CRP predicted REE at a single time point. REE change was highly variable and explained by inflammation and stage. Future research should investigate the validity and feasibility of incorporating these measures into energy needs recommendations.

Energy metabolism in cachexia

Cachexia is a wasting disorder that accompanies many chronic diseases including cancer and results from an imbalance of energy requirements and energy uptake. In cancer cachexia, tumor-secreted factors and/or tumor-host interactions cause this imbalance, leading to loss of adipose tissue and skeletal and cardiac muscle, which weakens the body. In this review, we discuss how energy enters the body and is utilized by the different organs, including the gut, liver, adipose tissue, and muscle, and how these organs contribute to the energy wasting observed in cachexia. We also discuss futile cycles both between the organs and within the cells, which are often used to fine-tune energy supply under physiologic conditions. Ultimately, understanding the complex interplay of pathologic energy-wasting circuits in cachexia can bring us closer to identifying effective treatment strategies for this devastating wasting disease.

Heterogeneity of endometriosis lesions requires individualisation of diagnosis and treatment and a different approach to research and evidence based medicine

Statistical significance is used to analyse research findings and is together with biased free trials the cornerstone of evidence based medicine. However traditional statistics are based on the assumption that the population investigated is homogeneous without smaller hidden subgroups. The clinical, inflammatory, immunological, biochemical, histochemical and genetic-epigenetic heterogeneity of similar looking endometriosis lesions is a challenge for research and for diagnosis and treatment of endometriosis. The conclusions obtained by statistical testing of the entire group are not necessarily valid for subgroups. The importance is illustrated by the fact that a treatment with a beneficial effect in 80% of women but with exactly the same but opposite effect, worsening the disease in 20%, remains statistically highly significant. Since traditional statistics are unable to detect hidden subgroups, new approaches are mandatory. For diagnosis and treatment it is suggested to visualise individual data and to pay specific attention to the extremes of an analysis. For research it is important to integrate clinical, biochemical and histochemical data with molecular biological pathways and genetic-epigenetic analysis of the lesions.