Is there a genetic cause of appetite loss?-an explorative study in 1,853 cancer patients

Inter-organ cross-talk in human cancer cachexia revealed by spatial metabolomics

BACKGROUND

Cancer cachexia (CCx) presents a multifaceted challenge characterized by negative protein and energy balance and systemic inflammatory response activation. While previous CCx studies predominantly focused on mouse models or human body fluids, there's an unmet need to elucidate the molecular inter-organ cross-talk underlying the pathophysiology of human CCx.

METHODS

Spatial metabolomics were conducted on liver, skeletal muscle, subcutaneous and visceral adipose tissue, and serum from cachectic and control cancer patients. Organ-wise comparisons were performed using component, pathway enrichment and correlation network analyses. Inter-organ correlations in CCx altered pathways were assessed using Circos. Machine learning on tissues and serum established classifiers as potential diagnostic biomarkers for CCx.

RESULTS

Distinct metabolic pathway alteration was detected in CCx, with adipose tissues and liver displaying the most significant (P ≤ 0.05) metabolic disturbances. CCx patients exhibited increased metabolic activity in visceral and subcutaneous adipose tissues and liver, contrasting with decreased activity in muscle and serum compared to control patients. Carbohydrate, lipid, amino acid, and vitamin metabolism emerged as highly interacting pathways across different organ systems in CCx. Muscle tissue showed decreased (P ≤ 0.001) energy charge in CCx patients, while liver and adipose tissues displayed increased energy charge (P ≤ 0.001). We stratified CCx patients by severity and metabolic changes, finding that visceral adipose tissue is most affected, especially in cases of severe cachexia. Morphometric analysis showed smaller (P ≤ 0.05) adipocyte size in visceral adipose tissue, indicating catabolic processes. We developed tissue-based classifiers for cancer cachexia specific to individual organs, facilitating the transfer of patient serum as minimally invasive diagnostic markers of CCx in the constitution of the organs.

CONCLUSIONS

These findings support the concept of CCx as a multi-organ syndrome with diverse metabolic alterations, providing insights into the pathophysiology and organ cross-talk of human CCx. This study pioneers spatial metabolomics for CCx, demonstrating the feasibility of distinguishing cachexia status at the organ level using serum.

Metabolic underpinnings of cancer-related fatigue

Cancer-related fatigue (CRF) is one of the most prevalent and detrimental complications of cancer. Emerging evidence suggests that obesity and insulin resistance are associated with CRF occurrence and severity in cancer patients and survivors. In this narrative review, we analyzed recent studies including both preclinical and clinical research on the relationship between obesity and/or insulin resistance and CRF. We also describe potential mechanisms for these relationships, though with the caveat that because the mechanisms underlying CRF are incompletely understood, the mechanisms mediating the association between obesity/insulin resistance and CRF are similarly incompletely delineated. The data suggest that, in addition to their effects to worsen CRF by directly promoting tumor growth and metastasis, obesity and insulin resistance may also contribute to CRF by inducing chronic inflammation, neuroendocrinological disturbance, and metabolic alterations. Furthermore, studies suggest that patients with obesity and insulin resistance experience more cancer-induced pain and are at more risk of emotional and behavioral disruptions correlated with CRF. However, other studies implied a potentially paradoxical impact of obesity and insulin resistance to reduce CRF symptoms. Despite the need for further investigation utilizing interventions to directly elucidate the mechanisms of cancer-related fatigue, current evidence demonstrates a correlation between obesity and/or insulin resistance and CRF, and suggests potential therapeutics for CRF by targeting obesity and/or obesity-related mediators.

Changes of gene expression in peripheral blood mononuclear cells of lung cancer patients with or without anorexia

BACKGROUND & AIMS

Anorexia is a disabling symptom in cancer and we aimed at investigating the role of changes in gene expression in lung cancer patients presenting with anorexia.

METHODS

Genome-wide transcriptomic profiling was assessed in PBMCs RNA from newly diagnosed lung cancer patients and in a control group. RT-qPCR was used for selected genes.

RESULTS

RNA-Seq analysis revealed among groups a large number of differentially expressed genes mainly implicated in immune system regulation, oxidative stress and cytokine-mediated inflammation signaling pathways. In particular, we identified a total of 983 DEGs (843 up-regulated; 140 down-regulated) in anorexic cancer compared to controls. A selected number of DEGs including ADAM8, SMAD4, CCR4 and CLU were differentially expressed within cancer group according to the presence/absence of anorexia. In terms of RT-qPCR, ADAM8 was less expressed in cancer patients than controls (p < 0.001), and in anorexic patients vs controls (p = 0.001). The expression of SMAD4 was lower in cancer vs controls (p = 0.005), and in anorexic patients vs controls (p = 0.009). We observed lower CCR4 expression in both anorexic and non-anorexic vs control (p = 0.004, p = 0.011, respectively) and a similar trend was present for CLU.

CONCLUSIONS

Our data shed new light on the role of specific genes and their associated molecular pathways as potential key mechanisms for the development of anorexia and may represent a novel landmark for understanding the complex pathophysiology of impaired appetite in cancer.

Psoas muscle index at the fifth lumbar vertebra as a predictor of survival in epithelial ovarian cancers

Almost a quarter of a century has passed since the term sarcopenia was defined. Sarcopenia is recognized as a poor prognostic factor in a variety of cancer types. In ovarian cancer, it remains controversial whether sarcopenia affects prognosis and how it should be evaluated. The present study aimed to evaluate the association between the volume of the psoas major muscle and survival in patients with epithelial ovarian cancer. Medical charts of patients with epithelial ovarian cancer who received first-line chemotherapy with paclitaxel and carboplatin at the National Defense Medical College Hospital (Tokorozawa, Japan) between April 2010 and January 2015 were retrospectively reviewed. The bilateral psoas major muscle areas at the fifth lumbar vertebra were measured using computed tomography images. The Institutional Review Board at National Defense Medical College Hospital (Tokorozawa, Japan) approved the study protocol. A total of 72 patients with epithelial ovarian cancer who received combination therapy with paclitaxel and carboplatin were identified and enrolled. The median psoas muscle index (PMI; psoas muscle major cross-sectional area divided by height squared) was 5.4 cm²/m² (range, 3.3-10.0). Patients with higher PMI had significantly improved overall survival (OS) compared with those with lower PMI [log-rank test P=0.014; hazard ratio (HR), 2.61; 95% confidence interval (CI), 1.21-6.06]. Multivariate analysis for OS revealed that lower PMI was an independent unfavorable prognostic factor (HR, 3.87; 95% CI, 1.37-12.1; P=0.0098). The volume of psoas major muscle mass could be a potential biomarker for prognosis in patients with epithelial ovarian cancer.

Inter-tissue communication in cancer cachexia

Cachexia is a systemic condition that occurs during many neoplastic diseases, such as cancer. Cachexia in cancer is characterized by loss of body weight and muscle and by adipose tissue wasting and systemic inflammation. Cancer cachexia is often associated with anorexia and increased energy expenditure. Even though the cachectic condition severely affects skeletal muscle, a tissue that accounts for ~40% of total body weight, it represents a multi-organ syndrome that involves tissues and organs such as white adipose tissue, brown adipose tissue, bone, brain, liver, gut and heart. Indeed, evidence suggests that non-muscle tissues and organs, as well as tumour tissues, secrete soluble factors that act on skeletal muscle to promote wasting. In addition, muscle tissue also releases various factors that can interact with the metabolism of other tissues during cancer. In this Review, we examine the effect of non-muscle tissues and inter-tissue communication in cancer cachexia and discuss studies aimed at developing novel therapeutic strategies for the condition.

Psoas muscle volume as a predictor of peripheral neurotoxicity induced by primary chemotherapy in ovarian cancers

PURPOSE

Low skeletal muscle mass (sarcopenia) has been reported to have an influence on survival and toxicities of chemotherapy in several solid tumors. The impact of sarcopenia on the treatment of ovarian cancers has not been determined. The present study aimed to evaluate correlation between sarcopenia and toxicities of chemotherapy in ovarian cancers.

METHODS

Medical charts of the ovarian cancer patients that received chemotherapy with paclitaxel and carboplatin at our hospital between 2010 and 2015 were retrospectively reviewed. Muscle areas of bilateral psoas major muscles at the fifth lumbar vertebra were measured using images obtained by computed tomography. The volume of muscle and clinicopathological factors were evaluated for toxicities of chemotherapy. The protocol of the present study was approved by the institutional review board of our institution.

RESULTS

A total of 76 patients with ovarian cancers were identified, and enrolled in the present study. Median psoas index (PI, the psoas muscle major cross-sectional area divided by the height squared) was 583 mm²/m² (range 326-999). The patients with low PI developed peripheral neuropathy more frequently compared with those with high PI (32 vs. 11%; P = 0.047). PI value was not associated with other toxicities such as neutropenia and thrombocytopenia. PI value was associated with grade 2 or higher peripheral neuropathy in univariate analysis (OR = 3.92; 95% CI 1.21-15.32; P = 0.02) and multivariate analysis (OR = 3.93; 95% CI 1.17-15.87; P = 0.03).

CONCLUSIONS

PI value was significantly associated with peripheral neuropathy induced by combination therapy with paclitaxel and carboplatin in ovarian cancer patients. Although further studies are needed to confirm the results, the volume of skeletal muscle mass could be a potential biomarker to predict toxicities in ovarian cancer patients.

Protein anabolic resistance in cancer: does it really exist?

PURPOSE OF REVIEW

Preventing unintentional weight and muscle loss is of crucial importance to maintain the condition and well-being of patients with cancer, improve treatment response and tolerance, and prolong survival. Anabolic resistance might explain why some cancer patients do not respond to nutritional intervention, but does recent evidence actually support this? We will discuss recent literature that casts doubt on attenuated anabolic potential in cancer.

RECENT FINDINGS

Although anabolic resistance was observed in the past, more recent studies have shown that advanced cancer patients have an anabolic potential after intake of high-quality proteins. Furthermore, a consistent linear relationship is observed in cancer between (essential) amino acid availability from the diet and net protein gain. The studied cancer patients, however, were often characterized by a normal or obese body weight, following the trend in the general population, and mild systemic inflammation. Factors like recent chemotherapy, surgery, or cachexia do not seem to attenuate the anabolic potential to feeding.

SUMMARY

Cancer patients have a normal anabolic potential which relates to the amount of essential amino acids in the meal. It remains to be determined if this is also the case in weak cancer patients with a short life expectancy and high systemic inflammation.

Nonmuscle Tissues Contribution to Cancer Cachexia

Cachexia is a syndrome associated with cancer, characterized by body weight loss, muscle and adipose tissue wasting, and inflammation, being often associated with anorexia. In spite of the fact that muscle tissue represents more than 40% of body weight and seems to be the main tissue involved in the wasting that occurs during cachexia, recent developments suggest that tissues/organs such as adipose (both brown and white), brain, liver, gut, and heart are directly involved in the cachectic process and may be responsible for muscle wasting. This suggests that cachexia is indeed a multiorgan syndrome. Bearing all this in mind, the aim of the present review is to examine the impact of nonmuscle tissues in cancer cachexia.

Genetic basis of interindividual susceptibility to cancer cachexia: selection of potential candidate gene polymorphisms for association studies

Cancer cachexia is a complex and multifactorial disease. Evolving definitions highlight the fact that a diverse range of biological processes contribute to cancer cachexia. Part of the variation in who will and who will not develop cancer cachexia may be genetically determined. As new definitions, classifications and biological targets continue to evolve, there is a need for reappraisal of the literature for future candidate association studies. This review summarizes genes identified or implicated as well as putative candidate genes contributing to cachexia, identified through diverse technology platforms and model systems to further guide association studies. A systematic search covering 1986-2012 was performed for potential candidate genes / genetic polymorphisms relating to cancer cachexia. All candidate genes were reviewed for functional polymorphisms or clinically significant polymorphisms associated with cachexia using the OMIM and GeneRIF databases. Pathway analysis software was used to reveal possible network associations between genes. Functionality of SNPs/genes was explored based on published literature, algorithms for detecting putative deleterious SNPs and interrogating the database for expression of quantitative trait loci (eQTLs). A total of 154 genes associated with cancer cachexia were identified and explored for functional polymorphisms. Of these 154 genes, 119 had a combined total of 281 polymorphisms with functional and/or clinical significance in terms of cachexia associated with them. Of these, 80 polymorphisms (in 51 genes) were replicated in more than one study with 24 polymorphisms found to influence two or more hallmarks of cachexia (i.e., inflammation, loss of fat mass and/or lean mass and reduced survival). Selection of candidate genes and polymorphisms is a key element of multigene study design. The present study provides a contemporary basis to select genes and/or polymorphisms for further association studies in cancer cachexia, and to develop their potential as susceptibility biomarkers of cachexia.

Can variability in the effect of opioids on refractory breathlessness be explained by genetic factors?

OBJECTIVES

Opioids modulate the perception of breathlessness with a considerable variation in response, with poor correlation between the required opioid dose and symptom severity. The objective of this hypothesis-generating, secondary analysis was to identify candidate single nucleotide polymorphisms (SNP) from those associated with opioid receptors, signalling or pain modulation to identify any related to intensity of breathlessness while on opioids. This can help to inform prospective studies and potentially lead to better tailoring of opioid therapy for refractory breathlessness.

SETTING

17 hospice/palliative care services (tertiary services) in 11 European countries.

PARTICIPANTS

2294 people over 18 years of age on regular opioids for pain related to cancer or its treatment.

PRIMARY OUTCOME MEASURES

The relationship between morphine dose, breathlessness intensity (European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire; EORTCQLQC30 question 8) and 112 candidate SNPs from 25 genes (n=588).

SECONDARY OUTCOME MEASURES

The same measures for people on oxycodone (n=402) or fentanyl (n=429).

RESULTS

SNPs not in Hardy-Weinberg equilibrium or with allele frequencies (<5%) were removed. Univariate associations between each SNP and breathlessness intensity were determined with Benjamini-Hochberg false discovery rate set at 20%. Multivariable ordinal logistic regression, clustering over country and adjusting for available confounders, was conducted with remaining SNPs. For univariate morphine associations, 1 variant on the 5-hydroxytryptamine type 3B (HTR3B) gene, and 4 on the β-2-arrestin gene (ARRB2) were associated with more intense breathlessness. 1 SNP remained significant in the multivariable model: people with rs7103572 SNP (HTR3B gene; present in 8.4% of the population) were three times more likely to have more intense breathlessness (OR 2.86; 95% CIs 1.46 to 5.62; p=0.002). No associations were seen with fentanyl nor with oxycodone.

CONCLUSIONS

This large, exploratory study identified 1 biologically plausible SNP that warrants further study in the response of breathlessness to morphine therapy.

Treatment of cachexia: an overview of recent developments

Body wasting in the context of chronic illness is associated with reduced quality of life and impaired survival. Recent clinical trials have investigated different approaches to improve patients' skeletal muscle mass and strength, exercise capacity, and survival in the context of cachexia and body wasting, many of them in patients with cancer. The aim of this article was to summarize clinical trials published over the past 2 years. Therapeutic approaches discussed include appetite stimulants, such as megestrol acetate, L-carnitine, or melatonin, anti-inflammatory drugs, such as thalidomide, pentoxyphylline, or a monoclonal antibody against interleukin-1α as well as ghrelin and the ghrelin agonist anamorelin; nutritional support, and anabolics, such as enobosarm and testosterone.

Cachexia: a preventable comorbidity of cancer. A T.A.R.G.E.T. approach

Although relevant achievements in the treatment of cancer have been obtained, some barriers still remain in the prevention and treatments of cancer comorbidities, including cachexia. Indeed, the enormous advances in the understanding of the pathogenesis of cancer cachexia have not been paralleled by effective strategies aimed at modifying the cultural approach to this devastating condition. Too little attention is still paid to the nutritional and metabolic changes occurring in cancer, despite their negative effects on patients' tolerance to antineoplastic treatments and outcome. We propose a T.A.R.G.E.T. approach as a novel strategy, encompassing active interventions and research development within the different domains influencing the onset and the progression of cancer cachexia. Moreover, based on the most recent clinical evidences, we suggest that cachexia should be considered a comorbidity of cancer.

Mechanism and novel therapeutic approaches to wasting in chronic disease

Cachexia is a multifactorial syndrome defined by continuous loss of skeletal muscle mass - with or without loss of fat mass - which cannot be fully reversed by conventional nutritional support and which may lead to progressive functional impairment and increased death risk. Its pathophysiology is characterized by negative protein and energy balance driven by a variable combination of reduced food intake and abnormal metabolism. Muscle wasting is encountered in virtually all chronic disease states in particular during advanced stages of the respective illness. Several pre-clinical and clinical studies are ongoing to ameliorate this clinical problem. The mechanisms of muscle wasting and cachexia in chronic diseases such as cancer, chronic heart failure, chronic obstructive pulmonary disease and chronic kidney disease are described. We discuss therapeutic targets and such potential modulators as appetite stimulants, selective androgen receptor modulators, amino acids and naturally occurring peptide hormones.