Anorexia in cancer: role of feeding-regulatory peptides

The Molecular Basis and Therapeutic Potential of Leukemia Inhibitory Factor in Cancer Cachexia

Simple Summary

The mechanism of cancer cachexia is linked to a variety of factors, and inflammatory factors are thought to play a key role. We summarize the main roles of LIF in the development of cancer cachexia, including promoting fat loss, inducing skeletal muscle atrophy and causing anorexia nervosa. The main aim of this review is to increase the understanding of the effects of LIF in cachexia and to provide new insights into the treatment of cancer cachexia.

Abstract

Cachexia is a chronic metabolic syndrome that is characterized by sustained weight and muscle mass loss and anorexia. Cachexia can be secondary to a variety of diseases and affects the prognosis of patients significantly. The increase in inflammatory cytokines in plasma is deeply related to the occurrence of cachexia. As a member of the IL-6 cytokine family, leukemia inhibitory factor (LIF) exerts multiple biological functions. LIF is over-expressed in the cancer cells and stromal cells of various tumors, promoting the malignant development of tumors via the autocrine and paracrine systems. Intriguingly, increasing studies have confirmed that LIF contributes to the progression of cachexia, especially in patients with metastatic tumors. This review combines all of the evidence to summarize the mechanism of LIF-induced cachexia from the following four aspects: (i) LIF and cancer-associated cachexia, (ii) LIF and alterations of adipose tissue in cachexia, (iii) LIF and anorexia nervosa in cachexia, and (iv) LIF and muscle atrophy in cachexia. Considering the complex mechanisms in cachexia, we also focus on the interactions between LIF and other key cytokines in cachexia and existing therapeutics targeting LIF.

The Effect of Cannabis-Based Medicine in the Treatment of Cachexia: A Systematic Review and Meta-Analysis

Background: Cachexia is a prevalent condition associated with underlying chronic disease. Wasting of skeletal muscle and adipose tissue loss in cachectic patients is associated with higher rates of disability, reduced quality of life (QoL), and worse prognosis. There is a large unmet need to develop strategies to treat cachexia as there are currently no standardized guidelines in the management of cachexia. Activation of endogenous cannabinoid receptors, through exogenous cannabinoids, has demonstrated potential in increasing appetite, reducing catabolism, and has shown anti-inflammatory properties. Since no single pharmacological agent is currently recommended for use in cachexia, the potential of cannabinoids as an appetite stimulant warrants further research and assessment of current evidence. Objective: This review aims to evaluate the evidence for the efficacy of cannabis-based medicinal products, against placebo and other active treatments, in anorexia-cachexia syndrome in improving appetite, weight, and QoL. Methods: A literature search of the Medline, EMBASE, CENTRAL, and the Web of Science Core Collection, for articles published up to February 2020, was conducted. All randomized controlled trials comparing the use of cannabis-based medicine versus placebo/active treatments for patients with cachexia were screened. The quality of evidence in included studies was assessed using the GRADE framework and any risk of bias was judged using the Cochrane risk of bias tool. Results: A total of five studies, encompassing 934 participants, were found to be eligible. The pooled group effect size for change in appetite was -1.79 (95% confidence interval: -3.77 to 0.19) favoring the control group (p=0.08). Additionally, no significant difference for weight change or change in QoL for cannabinoids versus placebo/other treatment was observed. The quality of evidence for all five studies was assessed to be low. Conclusion: There is a lack of high-quality evidence to recommend the use of cannabinoids in the treatment of cachexia. Given the limited available pharmacological options for cachexia and the potential for cannabinoids to increase appetite and alter the immune system, further research is needed before clinical recommendations on the pharmacological management of cachexia can be made.

Fed or fasted state for oral therapies in breast cancer treatment? A comprehensive review of clinical practice recommendations

In the last decades several anti-cancer drugs have been developed to treat patients with breast cancer, many of them orally administered, with ongoing efforts to substitute parenteral drugs with oral therapy. The latter is attractive because of its convenience and ease of administration, finally improving quality of life. The drawback of oral administration is that exposure to the drug is affected by different factors and the high variability, combined with the relatively narrow therapeutic index of most of these agents, would predispose some individuals to risk for treatment inefficacy or increase toxicity. Among these factors, food plays a central role since it can influence the pharmacokinetic profile of several drugs. Consequently, health care providers and patients should be aware of possible interaction to optimize treatment. In this review a systematic evaluation of package inserts and literature have been performed to analyse the effect of fed or fasted state on pharmacokinetic of all oral drugs currently approved for breast cancer, offering clear recommendations for their use daily practice.

Inflammatory cytokines and appetite in older hospitalized patients

It has already been confirmed that the decline in appetite during disease is a common issue and the biologic players of inflammation such as cytokines may serve as mediators of this effect. This study aimed to investigate the association of appetite with individual cytokines that could be involved in the inflammation-associated loss of appetite in acutely ill older hospitalized patients. 191 patients (mean age 81.3 ± 6.6 years, 64% women) participated in this prospective observational study. Risk of malnutrition and patient's appetite were evaluated using the Mini Nutritional Assessment Short Form and the Simplified Nutritional Appetite Questionnaire on admission, respectively. Serum C-reactive protein (CRP) and serum cytokines such as Interleukin 1 beta (IL-1β), IL-6, IL-8, IL-10, IL-12p70, IL-17, IL-18, IL-23 and IL-33, interferon alpha-2, interferon gamma, tumor necrosis factor alpha and monocyte chemoattractant protein-1 (MCP-1) were measured. Of total population, 30% had CRP>3.0 (mg/dL), 31% were malnourished and 31% demonstrated poor and very poor appetite. There were significant differences in the mean concentrations of a number of cytokines including IL-1β, MCP-1, IL-6, IL-10, IL-12p70, IL-18 and IL-23 across the appetite scores. In a regression analysis, an increased IL-18 level (P = 0.049) was the most prominent biomarker for poor appetite. No other significant associations between appetite and circulating levels of other cytokines were found in the regression analysis, except for IL-6 and IL-33, which were only significantly associated in the unadjusted model. The association of IL-18 with decreased appetite was independent from the severity of CRP-level and infections. In this study, certain cytokines, in particular IL-18 were associated with poor appetite in acutely diseased patients and should therefore be considered as a potential target of the prevention and treatment of malnutrition.

Dietary intake and diet quality in children receiving treatment for cancer

This narrative synthesis aims to examine the dietary intake, diet quality, and dietary preferences of pediatric cancer patients during cancer treatment. Thirteen studies were eligible for review. Studies mostly investigated nutrient intake, with 7 reporting on children's food intake. There was consensus among studies, which reported suboptimal fruit and vegetable intake and a preference for savory, carbohydrate-based foods. Results suggest that pediatric cancer patients consume a limited variety of foods, with a high intake of noncore foods. Future research should aim to examine dietary food data against dietary guidelines to assess adequacy and variety within core food groups.

Labeling and defining severe and enduring anorexia nervosa: A systematic review and critical analysis

OBJECTIVE

With anorexia nervosa (AN) having various presentations, attention has been directed towards particularly durable forms of the condition in both research and clinical contexts. A major hindrance in terms of advancing the field is the inconsistent labeling and defining of this subgroup. This has two implications; first, the inconsistent recruitment of participants when researching this sample, and second, the misdiagnosing of patients who may or may not have a durable course of the disease. The current research had the purpose of providing an overview of the current labels and criteria used for defining cases of severe and enduring AN, and critically analysing the implications of these findings.

METHOD

In accordance with PRISMA guidelines, a literature search was conducted using four electronic databases (PsycINFO, MEDLINE, Web of Science and Scopus) in order to identify 32 records that met the standards stipulated by the criteria. Data extraction included explicit labeling, the definition or criteria used to describe the subgroup, along with participant age and study design.

RESULTS

It was found that the terms chronic and severe and enduring were the most commonly used adjectives when referring to this subgroup. In terms of criteria, illness duration and the number of previously failed treatment attempts were the most common defining features within the literature.

DISCUSSION

It is the aim of the authors to inspire further research into what is the most appropriate label and defining features for the subgroup in order to facilitate a better approach and outcome for the individuals affected.

Lower blood pressure and risk of cisplatin nephrotoxicity: a retrospective cohort study

Background

The pathophysiological mechanisms of cisplatin nephrotoxicity include the reduction of renal blood flow, as well as tubular epithelial cell toxicity. The objective of this study was to investigate the influence of lower blood pressure and decreased food intake on the incidence of cisplatin nephrotoxicity.

Methods

We conducted a retrospective cohort study at a university hospital between 2011 and 2012. We identified hospitalized adult patients with head and neck cancer, esophageal cancer, or gastric cancer, who received intravenous cisplatin administration. The primary outcome was the incidence of cisplatin nephrotoxicity defined as the increase in serum creatinine after cisplatin administration more than 1.5 times from baseline.

Results

The study participants included 182 patients, in whom we observed a total of 442 cycles of cisplatin chemotherapy. The incidence of cisplatin nephrotoxicity was observed in 41 of 182 cycles with initial administration. Multivariate logistic regression analysis showed that systolic blood pressure was independently associated with cisplatin nephrotoxicity (adjusted odds ratio 0.75, 95% confidence interval 0.57 to 0.95 for each 10 mmHg). The use of renin-angiotensin system (RAS) inhibitors was also associated with cisplatin nephrotoxicity (3.39, 1.30 to 8.93). Among quartiles of systolic blood pressure in all cycles of chemotherapy, the incidence of nephrotoxicity in the lower blood pressure group was significantly higher than that in the higher blood pressure group for patients taking non-solid food (P = 0.037), while there was no significant difference for patients taking solid food (P = 0.67).

Conclusions

Lower blood pressure and the use of RAS inhibitors were associated with the incidence of cisplatin nephrotoxicity, and lower blood pressure had a greater influence on nephrotoxicity in patients who could not take solid food. Discontinuation of antihypertensive medication including RAS inhibitors before cisplatin chemotherapy should be considered, which may be beneficial for patients with lower blood pressure.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3135-6) contains supplementary material, which is available to authorized users.

Precipitating factors and targeted therapies in combating the perils of sickle cell disease--- A special nutritional consideration

Nutritional research in sickle cell disease has been the focus in recent times owing to not only specific nutritional deficiencies, but also the improvements associated with less painful episodes. Though hydroxyurea remains the drug of choice, certain adverse health effects on long term supplementation makes room for researches of different compounds. Macro and micro nutrient deficiencies, along with vitamins, play an important role in not only meeting the calorific needs, but also reducing clinical complications and growth abnormalities. Symptoms of hyper protein metabolism, increased cell turnover, increased cardiac output, and appetite suppression due to enhanced cytokine production, might give us leads for better understanding of the mechanisms involved. Different nutritional approaches comprising of traditional herbal therapies, antioxidants, flavonoids, vitamins, minerals etc., reducing oxidative stress and blood aggregation, have been tried out to increase the health potential. Nutritional therapies may also serve complementary to the newer therapies using ozone, hematopoietic stem cell transplantation, antifungal medications, erythropoietin etc. Herein we try to present a holistic picture of the different patho-physiological mechanisms, and nutritional strategies adopted.

Pentoxifylline treatment in patients with cancer cachexia: A double-blind, randomized, placebo-controlled clinical trial

Background:

Cachexia can occur as part of many end-stage or chronic diseases, and chronic obstructive pulmonary disease. This study was aimed to evaluate the effect of Pentoxifylline in patients with cancer cachexia.

Materials and Methods:

The present study was conducted as a double-blind randomized controlled trial on 70 patients with advanced malignancy who loss of >5% of ideal or preillness body weight in the previous 2 months. Patients were assessed in two groups: case group, under treatment, using Pentoxifylline (400 mg) three times a day, for 2 months, and in the control group, patients received placebo. Age, sex, weight change, change in arm circumference and quality of life were assessed at baseline, week-4 and week-8.

Results:

The mean age of the patients was 56 ± 17.3 years and 47% were female. Weight and arm circumference decreased during follow-up in both groups, but these differences between case and controls were not statistically significant. Quality of life (QOL) score in the case group improved after 4 weeks then decreased at the end of treatment but in the control group QOL score decreased during 2 month treatment. In week-4 patients in the case group significantly reported higher score of QOL compare to patients in the control group (P = 0.029).

Conclusion:

Results of this study demonstrated that Pentoxifylline in the treatment of cancer cachexia did not have any effect in weight gain and arm circumference in cachectic patients. But in short-term (1 month) treatment, QOL was improved in these patients. And after 2 month treatment this was not effective compared to placebo.

Rikkunshito, a ghrelin potentiator, ameliorates anorexia-cachexia syndrome

Anorexia–cachexia syndrome develops during the advanced stages of various chronic diseases in which patients exhibit a decreased food intake, weight loss, and muscle tissue wasting. For these patients, this syndrome is a critical problem leading to an increased rate of morbidity and mortality. The present pharmacological therapies for treating anorexia–cachexia have limited effectiveness. The Japanese herbal medicine rikkunshito is often prescribed for the treatment of anorexia and upper gastrointestinal (GI) disorders. Thus, rikkunshito is expected to be beneficial for the treatment of patients with anorexia–cachexia syndrome. In this review, we summarize the effects of rikkunshito and its mechanisms of action on anorexia–cachexia. Persistent loss of appetite leads to a progressive depletion of body energy stores, which is frequently associated with cachexia. Consequently, regulating appetite and energy homeostasis is critically important for treating cachexia. Ghrelin is mainly secreted from the stomach, and it plays an important role in initiating feeding, controlling GI motility, and regulating energy expenditure. Recent clinical and basic science studies have demonstrated that the critical mechanism of rikkunshito underlies endogenous ghrelin activity. Interestingly, several components of rikkunshito target multiple gastric and central sites, and regulate the secretion, receptor sensitization, and degradation of ghrelin. Rikkunshito is effective for the treatment of anorexia, body weight loss, muscle wasting, and anxiety-related behavior. Furthermore, treatment with rikkunshito was observed to prolong survival in an animal model of cachexia. The use of a potentiator of ghrelin signaling, such as rikkunshito, may represent a novel approach for the treatment of anorexia–cachexia syndrome.

Immunomodulatory effects of high-protein diet with resveratrol supplementation on radiation-induced acute-phase inflammation in rats

We hypothesized that a high-protein diet and/or resveratrol supplementation will improve acute inflammatory responses in rats after receiving experimental abdominal radiation treatment (ART). Based on our previous study, the period of 10 days after ART was used as an acute inflammation model. Rats were exposed to a radiation dose of 17.5 Gy and were supplied with a control (C), 30% high-protein diet (HP), resveratrol supplementation (RES), or HP with RES diet ([HP+RES]). At day 10 after ART, we measured profiles of lipids, proteins, and immune cells in blood. The levels of clusters of differentiating 4(+) (CD4(+)) cells and regulatory T cells, serum proinflammatory cytokines, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in urine were also measured. ART caused significant disturbances of lipid profiles by increasing triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C), and decreasing high-density lipoprotein cholesterol. The proinflammatroy cytokine levels were also increased by ART. All the experimental diets (HP, RES, and [HP+RES]) significantly decreased levels of TG, monocytes, proinflammatory cytokines, and 8-OHdG, whereas the platelet counts were increased. In addition, the HP and [HP+RES] diets decreased the concentrations of plasma LDL-C and total cholesterol. Also, the HP and RES diets decreased regulatory T cells compared with those of the control diet in ART group. Further, the HP diet led to a significant recovery of white blood cell counts, as well as increased percentages of lymphocyte and decreased percentages of neutrophils. In summary, RES appeared to be significantly effective in minimizing radiation-induced damage to lipid metabolism and immune responses. Our study also demonstrated the importance of dietary protein intake in recovering from acute inflammation by radiation.

Distribution of selenium and oxidative stress in breast tumor-bearing mice

The present study investigated the effects of breast tumors on the blood and tissue distribution of essential trace mineral selenium (Se), and oxidative stress status of mice. Female 10-week-old BALB/cByJNarl mice were randomly assigned into control (CNL) and breast tumor-bearing (TB) groups. TB mice were injected subcutaneously into the right hind thigh with 5 × 10(6) EMT6 mouse mammary tumor cells. After 22 days, we measured Se concentrations, Se-dependent glutathione peroxidase (GPx) activities, and malondialdehyde (MDA) products (indicator of oxidative stress) in plasma, various tissues, and plasma vascular endothelial growth factor (VEGF) concentrations. There were no significant differences in body weights and daily intake between both groups. Compared with the CNL group, TB mice have decreases in plasma Se concentrations and GPx activities, as well as higher plasma VEGF and MDA concentrations. Plasma Se concentrations were also negatively correlated with plasma MDA and VEGF concentrations. Furthermore, tissue Se concentrations and GPx activities in TB animals were lower; whereas the MDA concentrations higher in various tissues including liver, kidney, brain, lung, spleen, and thymic tissues. In conclusion, disruption of Se homeostasis critically reflects oxidative stress in target tissues, thus may increase the risk for progression of breast cancer and metastasis.

Management of Anorexia-Cachexia in Late Stage Lung Cancer Patients

Nutritional deficiencies are experienced by most adults with advanced lung cancer during the course of their disease and treatment. Well-nourished individuals tolerate cancer treatment with less morbidity, mortality, and increased response to treatment as compared to those who are malnourished. Novel anti-cancer therapies cause many deficits that impact nutritional and functional status during the treatment process. Nutritional deficits include weight loss, malnutrition, and anorexia-cachexia. Anorexia-Cachexia is complex, not well understood and seen in many solid tumors in late stage disease. Assessing adequate nutrition is one of the most challenging problems for nurses, their patients and patient's families. The purpose of this review is to define and describe cancer anorexia-cachexia in late stage lung cancer, through case presentation, and to describe palliative strategies for prevention, assessment, and management in the palliative care setting. Early assessment for nutritional imbalances must be done regularly with re-evaluation for intervention effectiveness and should continue throughout the illness trajectory. Management of adverse effects of cancer and cancer-related treatment is critical to improving quality of life. Palliative care and hospice nurses play a critical role in early assessment, education and prevention to support nutritional needs for patients and their families.

Integrative role of neuropeptides and cytokines in cancer anorexia-cachexia syndrome

BACKGROUND

The cachexia anorexia syndrome is a complex metabolic syndrome associated with cancer and some other palliative conditions characterized by involuntary weight loss involving fat and muscle, weight loss, anorexia, early satiety, fatigue, weakness due to shifts in metabolism caused by tumour by-products and cytokines. Various neuropeptides like Leptin, neuropeptide Y, melanocortin, agouti-related peptides have been known to regulate appetite and body weight.

METHOD

A comprehensive literature search was carried out on the websites of Pubmed Central (http://www.pubmedcentral.nih.gov/), National Library of Medicine (http://www.ncbl.nlm.nih.gov) and various other net resources.

RESULT

Data from observational studies shows that various cytokines (TNF-α, IL-6 and IL-1) are associated with metabolic changes resulting in cachexia in cancer patients. These cytokines may mimic the action of various neuropeptides resulting in anorexia, various metabolic effects resulting from enhanced catabolic state and weight loss.

CONCLUSION

There is a need to understand and explore the role of various neuropeptides and cytokines in the pathophysiology of cancer-anorexia syndrome so that therapeutic measures may be designed for effective palliative care.

Potentiation of ghrelin signaling attenuates cancer anorexia-cachexia and prolongs survival

Cancer anorexia-cachexia syndrome is characterized by decreased food intake, weight loss, muscle tissue wasting and psychological distress, and this syndrome is a major source of increased morbidity and mortality in cancer patients. This study aimed to clarify the gut-brain peptides involved in the pathogenesis of the syndrome and determine effective treatment for cancer anorexia-cachexia. We show that both ghrelin insufficiency and resistance were observed in tumor-bearing rats. Corticotropin-releasing factor (CRF) decreased the plasma level of acyl ghrelin, and its receptor antagonist, α-helical CRF, increased food intake of these rats. The serotonin 2c receptor (5-HT2cR) antagonist SB242084 decreased hypothalamic CRF level and improved anorexia, gastrointestinal (GI) dysmotility and body weight loss. The ghrelin receptor antagonist (D-Lys3)-GHRP-6 worsened anorexia and hastened death in tumor-bearing rats. Ghrelin attenuated anorexia-cachexia in the short term, but failed to prolong survival, as did SB242084 administration. In addition, the herbal medicine rikkunshito improved anorexia, GI dysmotility, muscle wasting, and anxiety-related behavior and prolonged survival in animals and patients with cancer. The appetite-stimulating effect of rikkunshito was blocked by (D-Lys3)-GHRP-6. Active components of rikkunshito, hesperidin and atractylodin, potentiated ghrelin secretion and receptor signaling, respectively, and atractylodin prolonged survival in tumor-bearing rats. Our study demonstrates that the integrated mechanism underlying cancer anorexia-cachexia involves lowered ghrelin signaling due to excessive hypothalamic interactions of 5-HT with CRF through the 5-HT2cR. Potentiation of ghrelin receptor signaling may be an attractive treatment for anorexia, muscle wasting and prolong survival in patients with cancer anorexia-cachexia.

Randomized phase III clinical trial of five different arms of treatment in 332 patients with cancer cachexia

PURPOSE

A phase III, randomized study was carried out to establish the most effective and safest treatment to improve the primary endpoints of cancer cachexia-lean body mass (LBM), resting energy expenditure (REE), and fatigue-and relevant secondary endpoints: appetite, quality of life, grip strength, Glasgow Prognostic Score (GPS) and proinflammatory cytokines.

PATIENTS AND METHODS

Three hundred thirty-two assessable patients with cancer-related anorexia/cachexia syndrome were randomly assigned to one of five treatment arms: arm 1, medroxyprogesterone (500 mg/day) or megestrol acetate (320 mg/day); arm 2, oral supplementation with eicosapentaenoic acid; arm 3, L-carnitine (4 g/day); arm 4, thalidomide (200 mg/day); and arm 5, a combination of the above. Treatment duration was 4 months.

RESULTS

Analysis of variance showed a significant difference between treatment arms. A post hoc analysis showed the superiority of arm 5 over the others for all primary endpoints. An analysis of changes from baseline showed that LBM (by dual-energy X-ray absorptiometry and by L3 computed tomography) significantly increased in arm 5. REE decreased significantly and fatigue improved significantly in arm 5. Appetite increased significantly in arm 5; interleukin (IL)-6 decreased significantly in arm 5 and arm 4; GPS and Eastern Cooperative Oncology Group performance status (ECOG PS) score decreased significantly in arm 5, arm 4, and arm 3. Toxicity was quite negligible, and was comparable between arms.

CONCLUSION

The most effective treatment in terms of all three primary efficacy endpoints and the secondary endpoints appetite, IL-6, GPS, and ECOG PS score was the combination regimen that included all selected agents.

Phase II nonrandomized study of the efficacy and safety of COX-2 inhibitor celecoxib on patients with cancer cachexia

Chronic inflammation is one of the main features of cancer cachexia. Experimental and clinical studies showed that cyclooxygenase-2 inhibitors, such as celecoxib, may be beneficial in counteracting major symptoms of this devastating syndrome. We carried out a prospective phase II clinical trial to test the safety and effectiveness of an intervention with the COX-2 inhibitor celecoxib (300 mg/day for 4 months) on key variables of cachexia (lean body mass, resting energy expenditure, serum levels of proinflammatory cytokines, and fatigue) in patients with advanced cancer at different sites. A sample of 24 patients was enrolled from January to December 2008 and all were deemed assessable. A significant increase of lean body mass and a significant decrease of TNF-alpha were observed. Moreover, an improvement of grip strength, quality of life, performance status, and Glasgow prognostic score was shown. There were no grade 3/4 toxicities. Patient compliance was very good; no patient had to reduce the celecoxib dosage nor interrupt treatment. Our results showed that the COX-2 selective inhibitor celecoxib is an effective single agent for the treatment of cancer cachexia. Although the treatment of cancer cachexia, a multifactorial syndrome, is more likely to yield success with a multitargeted approach; in the present study, we were able to show that a treatment, such as celecoxib, addressing a single target, albeit very important as chronic inflammation, could have positive effects. Therefore, phase III clinical trials are warranted to test the efficacy and safety of celecoxib.

The Inappetent Hospitalised Cat: clinical approach to maximising nutritional support

PRACTICAL RELEVANCE

Inappetence is one of the most common presenting complaints in clinically ill cats requiring hospitalisation. When prolonged, poor food intake can lead to malnutrition and may be associated with impaired metabolic function, immunosuppression, compromised wound healing, and increased morbidity and mortality. It is important to recognise that inappetence or anorexia is always secondary to another condition, and that treatment goals should be targeted at the primary condition. The current emphasis in the nutritional support of hospitalised inappetent cats is to provide more effective means of increasing nutritional intake--for example, by initiating enteral nutrition via feeding tubes-- rather than rely solely on traditional approaches such as increasing palatability of foods or using appetite-stimulating drugs.

CLINICAL CHALLENGES

Cats that are ill enough to require hospitalisation are at increased risk of becoming malnourished because of the combined catabolic effects of their disease and poor nutritional intake. This article highlights some of the problems encountered in treating inappetent cats and discusses a clinical approach to providing better nutritional support.

PATIENT GROUP

Inappetence and anorexia are associated with a myriad of clinical conditions in cats and can be seen in individuals of any age or breed.

EQUIPMENT

Provision of nutritional support to cats may involve the use of feeding tubes such as naso-oesophageal or oesophagostomy tubes. In cases where enteral nutrition is not feasible (eg, cats with gastrointestinal failure), parenteral nutrition should be considered.

EVIDENCE BASE

Various studies have documented the high prevalence of inappetence or anorexia in clinically ill cats. Additional studies have linked poor food intake in cats with serious sequelae such as immunosuppression and hepatic lipidosis. More recently, techniques for providing more effective nutritional support, such as oesophagostomy tubes, have been clinically evaluated and shown to be associated with minimal complications.

Feeding behavior in mammals including humans

The complex control of food intake and energy metabolism in mammals relies on the ability of the brain to integrate multiple signals indicating the nutritional state and the energy level of the organism and to produce appropriate responses in terms of food intake, energy expenditure, and metabolic activity. Central regulation of feeding is organized as a long-loop mechanism involving humoral signals and afferent neuronal pathways to the brain, processing in hypothalamic neuronal circuits, and descending commands using vagal and spinal neurons. Sensor mechanisms or receptors sensitive to glucose and fatty acid metabolism, neuropeptide and cannabinoid receptors, as well as neurotransmitters and neuromodulators synthesized and secreted within the brain itself are all signals integrated in the hypothalamus, which therefore functions as an integrator of signals from central and peripheral structures. Homeostatic feedback mechanisms involving afferent neuroendocrine inputs from peripheral organs, like adipose tissue, gut, stomach, endocrine pancreas, adrenal, muscle, and liver, to hypothalamic sites thus contribute to the maintenance of normal feeding behavior and energy balance. In addition to transcriptional events, peripheral hormones may also alter firing and/or connection (synaptology) of hypothalamic neuronal networks in order to modulate food intake. Moreover, intracellular energy sensing and subsequent biochemical adaptations, including an increase in AMP-activated protein kinase activity, occur in hypothalamic neurons. Understanding the regulation of appetite is clearly a major research effort but also seems promising for the development of novel therapeutic strategies for obesity.

Estudo comparativo de indicadores nutricionais em pacientes com neoplasias do trato digestório

RACIONAL: O câncer tem sido considerado atualmente como um dos principais problemas de saúde pública em todo o mundo e os tumores mais frequentes são os dos tratos gastrintestinal e o respiratório. OBJETIVO: Comparar indicadores do estado nutricional em pacientes portadores de neoplasias do trato digestório. MÉTODO: Estudo comparativo de indicadores nutricionais (antropométricos, laboratoriais e dietéticos), entre 28 pacientes portadores de neoplasias do trato digestório (esofágicas, gástricas e intestinais), em um hospital universitário. RESULTADOS: Não foi encontrada diferença significativa entre os três grupos de neoplasia para os indicadores laboratoriais, de consumo alimentar e antropométricos, exceto para a circunferência do braço (P=0,0471). A perda de peso ocorrida durante a internação foi observada em 46,4% dos pacientes estudados e a dieta enteral foi a prescrição dietética mais prevalente entre os pacientes, especialmente nos portadores de neoplasia de esôfago. CONCLUSÃO: Pacientes com diagnóstico de neoplasia de trato digestório apresentam comprometimento no estado nutricional e necessitam de acompanhamento nutricional no decorrer do tratamento destas enfermidades.

Regulation of adipose tissue metabolism in cancer cachexia

PURPOSE OF REVIEW

Body-fat depletion is a hallmark of cancer cachexia, a complex clinical syndrome associated with increased morbidity and mortality. Understanding the fat-loss disorder in cachexia is essential for the development of better treatments for the syndrome. This review presents recent studies focusing on the mechanisms of adipose atrophy in cancer cachexia, particularly the potential mediators.

RECENT FINDINGS

Fat loss cannot be explained by poor appetite alone, and may also result from altered lipid metabolism in adipocytes. Increased lipolysis appears to be a key factor underlying fat loss in cancer cachexia though decreases in lipid deposition and adipocyte development may also contribute. Both tumour and host-derived factors are implicated in adipose tissue atrophy. Tumour necrosis factor-alpha has been associated with increased lipolysis in adipocytes. The novel adipokine zinc-alpha2-glycoprotein may function locally, as well as systemically, to promote lipid mobilization and utilization in cancer cachexia.

SUMMARY

Clarifying the role of cachexia mediators in adipose tissue atrophy will add to our understanding of adipocyte metabolism in wasting disease. Elucidating their mode of action may lead to novel therapeutic targets for counteracting the cachexia syndrome.

Randomized phase III clinical trial of five different arms of treatment for patients with cancer cachexia: interim results

OBJECTIVE

In April 2005 a phase III randomized study was started to establish which was the most effective and safest treatment of cancer-related anorexia/cachexia syndrome and oxidative stress in improving identified primary endpoints: increase of lean body mass, decrease of resting energy expenditure (REE), increase of total daily physical activity, decrease of interleukin-6 and tumor necrosis factor-alpha, and improvement of fatigue assessed by the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF).

METHODS

All patients were given as basic treatment polyphenols plus antioxidant agents alpha-lipoic acid, carbocysteine, and vitamins A, C, and E, all orally. Patients were then randomized to one of the following five arms: 1) medroxyprogesterone acetate/megestrol acetate; 2) pharmacologic nutritional support containing eicosapentaenoic acid; 3) L-carnitine; 4) thalidomide; or 5) medroxyprogesterone acetate/megestrol acetate plus pharmacologic nutritional support plus L-carnitine plus thalidomide. Treatment duration was 4 mo. The sample comprised 475 patients.

RESULTS

By January 2007, 125 patients, well balanced for all clinical characteristics, were included. No severe side effects were observed. As for efficacy, an interim analysis on 125 patients showed an improvement of at least one primary endpoint in arms 3, 4, and 5, whereas arm 2 showed a significant worsening of lean body mass, REE, and MFSI-SF. Analysis of variance comparing the change of primary endpoints between arms showed a significant improvement of REE in favor of arm 5 versus arm 2 and a significant improvement of MFSI-SF in favor of arms 1, 3, and 5 versus arm 2. A significant inferiority of arm 2 versus arms 3, 4, and 5 for the primary endpoints lean body mass, REE, and MFSI-SF was observed on the basis of t test for changes.

CONCLUSION

The interim results obtained thus far seem to suggest that the most effective treatment for cancer-related anorexia/cachexia syndrome and oxidative stress should be a combination regimen. The study is still in progress and the final results should confirm these data.