The syndrome of anorexia-cachexia

Metformin reduces the Walker-256 tumor development in obese-MSG rats via AMPK and FOXO3a

AIMS

Studies have associated obesity with a wide variety of cancers. Metformin, an anti-diabetic drug, has recently received attention as a potentially useful therapeutic agent for treating cancer. Therefore, the objective of this study was to analyze the mechanisms involved in the increase in tumor development and the reduction of it by metformin in obesity using an experimental breast tumor model.

MATERIAL AND METHODS

Newborn male Wistar rats were subcutaneously injected with 400mg/kg monosodium glutamate (MSG) (obese) or saline (control) at 2, 3, 4, 5 and 6 days of age. After 16 weeks, 1 × 10(7) Walker-256 tumor cells were subcutaneously injected in the right flank of the rats and concomitantly the treatment with metformin 300 mg/kg/15 days, via gavage, started. The rats were divided into 4 groups: control tumor (CT), control tumor metformin (CTM), obese-MSG tumor (OT) and obese-MSG tumor metformin (OTM). On the 18th week the tumor development and metformin effect were analyzed.

KEY FINDINGS

Tumor development was higher in OT rats compared with CT rats. Activation of insulin-IR-ERK1/2 pathway and an anti-apoptotic effect might be the mechanisms involved in the higher development of tumor in obesity. The effect of metformin reducing the tumor development in obese rats might involve increased mRNA expression of pRb and p27, increased activity of AMPK and FOXO3a and decreased expression of p-ERK1/2 (Thr202/Tyr204) in Walker-256 tumor.

SIGNIFICANCE

Our data allow us to suggest that metformin, reducing the stimulatory effect of obesity on tumor development, has a potential role in the management of cancers.

Proteomic profiling of the hypothalamus in a mouse model of cancer-induced anorexia-cachexia

BACKGROUND

Anorexia-cachexia is a common and severe cancer-related complication but the underlying mechanisms are largely unknown. Here, using a mouse model for tumour-induced anorexia-cachexia, we screened for proteins that are differentially expressed in the hypothalamus, the brain's metabolic control centre.

METHODS

The hypothalamus of tumour-bearing mice with implanted methylcholanthrene-induced sarcoma (MCG 101) displaying anorexia and their sham-implanted pair-fed or free-fed littermates was examined using two-dimensional electrophoresis (2-DE)-based comparative proteomics. Differentially expressed proteins were identified by liquid chromatography-tandem mass spectrometry.

RESULTS

The 2-DE data showed an increased expression of dynamin 1, hexokinase, pyruvate carboxylase, oxoglutarate dehydrogenase, and N-ethylmaleimide-sensitive factor in tumour-bearing mice, whereas heat-shock 70 kDa cognate protein, selenium-binding protein 1, and guanine nucleotide-binding protein Gα0 were downregulated. The expression of several of the identified proteins was similarly altered also in the caloric-restricted pair-fed mice, suggesting an involvement of these proteins in brain metabolic adaptation to restricted nutrient availability. However, the expression of dynamin 1, which is required for receptor internalisation, and of hexokinase, and pyruvate carboxylase were specifically changed in tumour-bearing mice with anorexia.

CONCLUSION

The identified differentially expressed proteins may be new candidate molecules involved in the pathophysiology of tumour-induced anorexia-cachexia.

Cachexia, malnutrition, the refeeding syndrome, and lessons from Goldilocks

Cachexia has plagued clinicians for centuries. Although all cachexia is related to malnutrition, cachexia associated with malignant diseases differs from starvation cachexia in that it is more recalcitrant to nutritional therapy. All cachexia responds to judicious nutritional support; however, cancer cachexia worsens autonomously as the disease advances and cannot be arrested or reversed by any known form of nutrition, hormonal, or pharmacologic therapy. Cachexia must be treated cautiously to avoid overfeeding syndrome, which may result in serious or dangerous complications or death.

Metformin reduces the stimulatory effect of obesity on in vivo Walker-256 tumor development and increases the area of tumor necrosis

AIMS

The objective of this study was to analyze the influence of obesity and insulin resistance on tumor development and, in turn, the effect of insulin sensitizing agents.

MAIN METHODS

Male offspring of Wistar rats received monosodium glutamate (400mg/kg) (obese) or saline (control) from the second to sixth day after birth. Sixteen-week-old control and obese rats received 5×10(5) Walker-256 tumor cells, subcutaneously injected into the right flank. Some of the obese and control rats received concomitant treatment with metformin (300mg/kg) by gavage. At the 18th week, obesity was characterized. The percentage of rats that developed tumors, the tumor relative weight and the percentage of cachexia incidence were analyzed. The tumor tissue was evaluated histologically by means of hematoxylin and eosin staining.

KEY FINDINGS

Metformin did not correct the insulin resistance in obese rats. The tumor development was significantly higher in the obese group, whereas metformin treatment reduced it. After pathological analysis, we observed that the tumor tissues were similar in all groups except for adipocytes, which were found in greater quantity in the obese and metformin-treated obese groups. The area of tumor necrosis was higher in the group treated with metformin when compared with the untreated one.

SIGNIFICANCE

Metformin reduced Walker-256 tumor development but not cachexia in obese rats. The reduction occurred independently of the correction of insulin resistance. Metformin increased the area of necrosis in tumor tissues, which may have contributed to the reduced tumor development.

Angiogenesis and Anti-angiogenic Therapy in Myelofibrosis with Myeloid Metaplasia

Myelofibrosis with myeloid metaplasia (MMM) is a clonal stem cell disorder that is characterized by florid bone marrow stromal reaction including collagen fibrosis, osteosclerosis, and angiogenesis. Almost all patients with MMM display increased bone marrow microvessel density (MVD) and the extent is among the highest in hematological malignancies. This particular information has encouraged the therapeutic use of anti-angiogenic drugs in MMM. In the current review, we summarize the general concepts regarding angiogenesis, assessment of angiogenesis in hematological malignancies and then the current literature on angiogenesis and anti-angiogenic therapy in MMM.

New approaches in the treatment of myelofibrosis

Myelofibrosis with myeloid metaplasia (MMM) is a chronic clonal neoangiogenesis disorder characterized by bone marrow fibrosis and neoangiogensis with extramedullary hematopoiesis. Identification of prognostic factors associated with MMM have not impacted the treatment of the disease, which continues to be palliative with the exception of allogeneic stem cell transplantation (SCT) for potential long-term disease-free survival in selected patients. Additional insights into the pathophysiology of MMM have resulted in the use of novel therapeutic strategies in the treatment of this disease. The rationale for the investigation of these agents in MMM and the status of clinical trials with various modalities such as angiogenesis inhibitors (e.g., thalidomide), tyrosine kinase inhibitors (e.g., imatinib mesylate), farnesyl transferase inhibitors (e.g., R115777), and other agents are reviewed, in addition to the potential roles of autologous and allogeneic SCT.

Nutritional status of cancer patients and its relationship to function in an inpatient rehabilitation setting

BACKGROUND

Malnutrition is associated with prolonged hospitalization, lower survival rate, and various medical complications. However, little is known about malnutrition and its relationship with the functional status. We undertook this retrospective study to examine whether or not malnutrition affects rehabilitation outcome in patients who had undergone cancer rehabilitation.

METHODS

We conducted a review of the charts of 30 consecutive cancer patients who had been admitted to the inpatient rehabilitation unit in a tertiary cancer center, from the beginning of March 2001 to the end of April 2001.

RESULTS

The patients' mean rehabilitation stay was 9 days and their mean age was 58 years (range 22-86 years). On rehabilitation admission, 15 of the patients (50%) had a below normal prealbumin (<18 mg/dl) level (95% confidence interval 31-69%), and on discharge 10 of the patients (33%) had a below normal prealbumin level (95% CI 17-54%). The serum prealbumin concentration level correlated with motor functional independence measure scores on admission. After inpatient rehabilitation, statistically significant gains in functional independence measure scores (P<0.0001) were obtained in patients with below normal admission prealbumin, as well as in those whose prealbumin levels were within the normal range; no statistically significant difference was found in functional gain between these two groups.

CONCLUSION

Our study showed that a large number of cancer rehabilitation patients had malnutrition. Nevertheless, functional gain was achieved in all patients after rehabilitation, whether or not malnutrition was present. We conclude that malnourished patients should still be considered candidates for rehabilitation.

Cancer cachexia is regulated by selective targeting of skeletal muscle gene products

Cachexia is a syndrome characterized by wasting of skeletal muscle and contributes to nearly one-third of all cancer deaths. Cytokines and tumor factors mediate wasting by suppressing muscle gene products, but exactly which products are targeted by these cachectic factors is not well understood. Because of their functional relevance to muscle architecture, such targets are presumed to represent myofibrillar proteins, but whether these proteins are regulated in a general or a selective manner is also unclear. Here we demonstrate, using in vitro and in vivo models of muscle wasting, that cachectic factors are remarkably selective in targeting myosin heavy chain. In myotubes and mouse muscles, TNF-alpha plus IFN-gamma strongly reduced myosin expression through an RNA-dependent mechanism. Likewise, colon-26 tumors in mice caused the selective reduction of this myofibrillar protein, and this reduction correlated with wasting. Under these conditions, however, loss of myosin was associated with the ubiquitin-dependent proteasome pathway, which suggests that mechanisms used to regulate the expression of muscle proteins may be cachectic factor specific. These results shed new light on cancer cachexia by revealing that wasting does not result from a general downregulation of muscle proteins but rather is highly selective as to which proteins are targeted during the wasting state.

Nursing management of nutrition in cancer and palliative care

Malnutrition is prevalent in patients with cancer. This can have deleterious effects including reduced response to treatment, diminished quality of life, increased length of hospital stay and decreased survival. It is, therefore, imperative that thorough nutritional screening is carried out by nurses on patients' admission and during their hospital stay to detect those who are malnourished or at risk of malnutrition in order to plan their nutritional care effectively. Cancer cachexia is the progressive weight loss and emaciation seen in cancer patients, particularly in advanced disease, which can have a devastating effect on the physical, psychological, social and spiritual aspects of the patient's life. Therefore, the aims of nutritional care are identified depending on the stage of the patient's illness and recommendations made for nursing, pharmacological and nutritional intervention. These include nursing comfort strategies, the use of recommended pharmacological agents and dietary interventions such as experimenting with different foods, textures, portion sizes and nutritional supplements. The use of fish oil-enhanced nutritional supplements and artificial nutritional support is also discussed. Consideration is also given to the legal and ethical aspects of providing nutrition and nutritional support.

Body mass and survival in patients with chronic heart failure without cachexia: the importance of obesity

BACKGROUND

Cachexia in chronic heart failure carries a poor prognosis, but little is known about the influence of body mass on the prognosis of noncachectic heart failure patients.

METHODS

We studied 589 consecutive chronic heart failure patients followed for at least a year, in whom there were accurate baseline data for body mass.

RESULTS

Average age was 64.5 +/- 12.4 years, left ventricular ejection fraction (LVEF) 30.9 +/- 0.73%. Cachexia was present in 64. Noncachectic patients were divided into quintiles of body mass index (BMI), Q1 (BMI 22.2 +/- 1.5) to Q5 (BMI 34.1 +/- 2.8). There was no difference among the 5 groups in age, exercise capacity or LVEF. Survival was greatest in Q4 (1-year survival [95% confidence interval (CI)]) 0.91 (0.85-0.96) and 3-year survival 0.81 (0.73-0.89). Relative risks compared with Q4 were Q1: 2.3 (1.4-3.8); Q2: 1.7 (1.1-2.9); Q3: 1.8 (1.1-3.0); and Q5: 1.5 (0.9-2.5). In multivariate analysis of 1 year follow-up, peak oxygen consumption (hazard ratio with 95% CI) (0.89 [0.82-0.97]; P =.006), LVEF (0.94 [0.91-0.97]; P =.0002) and BMI (0.90 [0.82-0.98]; P =.02) independently predicted 1-year survival with a combined Chi;(2) value of 42.4. Age (1.01 [0.98-1.05] and diagnosis (1.56 [0.78-3.11]) was not a predictor of survival.

CONCLUSION

In patients with chronic heart failure, increasing BMI is not an adverse prognostic feature. Thinner patients appear to have a poorer prognosis.

What we have learned about cachexia in gastrointestinal cancer

It is appreciated widely by clinicians that significant malnutrition accompanies malignant processes in approximately 50% of patients and eventually leads to severe wasting which accounts for approximately 30% of cancer-related deaths overall, 30-50% of deaths in patients with gastrointestinal tract cancers, and up to 80% of deaths in patients with advanced pancreatic cancer. The body wasting known as cancer cachexia is a complex syndrome characterized by progressive tissue depletion and decreased nutrient intake that is manifested clinically as inexplicable, recalcitrant anorexia and inexorable host weight loss. Decreased nutritional intake, increased metabolic expenditure and dysfunctional metabolic processes, including hormonal and cytokine-related abnormalities, all appear to play roles in the development of cancer cachexia. Although this condition of advanced protein-calorie malnutrition, sometimes described as the cancer anorexia-cachexia syndrome, is not entirely understood, it appears to be multifactorial, is a major cause of morbidity and mortality in cancer patients, and ultimately leads to death. Therapeutic interventions have met with little success, and, regardless of tremendous efforts throughout the decades, the exact nature of the mediators responsible for cancer cachexia remain elusive. The pathogenesis of cancer cachexia appears to be related to proinflammatory cytokines, alterations in the neuroendocrine axis and tumor-derived catabolic factors. Despite trials of conventional and/or aggressive nutritional support by a myriad of feeding techniques, patients with cancer cachexia have failed to gain consistent significant benefits in terms of weight gain, functional ability, quality of life or survival. Additionally, attempts to ameliorate the abnormal clinical and metabolic features of cancer cachexia with a variety of pharmacologic agents have met with only limited success. Either until cancer of the gastrointestinal tract can be cured or until it is possible to identify the exact causes and mechanisms of the cancer cachexia syndrome, the most realistic and practical options currently are directed toward minimizing adverse gastrointestinal side effects or complications of the malignant process and/or therapy, as well as increasing appetite, food intake and nutrient utilization in an effort to enhance quality of life and improve survival.

Loss of weight and loss of appetite in advanced cancer: a problem for the patient, the carer, or the health professional?

This paper aims to examine the loss of weight and loss of appetite as 'problems' experienced by patients with advanced cancer and those that care for them. It reports the results of a systematic search of the literature and presents the findings as a narrative review. Research to date has focused upon charting the prevalence and incidence of these symptoms, but little empirical work has been conducted to investigate how patients and carers experience these problems. There is some evidence to suggest that anorexia may be more distressing for those caring for the patient than the person suffering from the symptom itself. Understanding the reason for this anguish requires an appreciation of the meaning of food refusal and constitutes the first step towards informing the development of effective interventions. Such exploratory work is mandatory if health professionals wish to move beyond speculation and deliver interventions that provide meaningful benefits for the cancer patient and their family.

Molecular-based therapeutic approaches in treatment of anorexia of aging and cancer cachexia

Loss of appetite, or anorexia, has profound implications for older persons, altering social interactions, reducing quality of life, and leading to weight loss with grave health consequences. Two conditions associated with anorexia considered in this article are the multidetermined anorexia of aging and the wasting syndrome termed cachexia induced by cancer. Nutritional interventions may have some benefit in the former, but are of limited value in the latter. Emerging studies at the molecular level relating to appetite regulation and energy balance may offer new approaches to arrest progressive weight loss in the anorexia of aging and cancer cachexia.

Etanercept, a soluble tumor necrosis factor receptor, palliates constitutional symptoms in patients with myelofibrosis with myeloid metaplasia: results of a pilot study

Patients with myelofibrosis with myeloid metaplasia (MMM) often experience debilitating constitutional symptoms such as drenching night sweats, profound fatigue, unexplained fevers, and unintentional weight loss. Tumor necrosis factor (TNF) contributes to organ fibrosis and hypercatabolic symptoms in a variety of disease states. We conducted an open-label pilot study of etanercept, a soluble TNF receptor, administered at a dose of 25 mg subcutaneously twice weekly for up to 24 weeks in 22 patients with MMM. Of 20 evaluable patients, 12 (60%) experienced an improvement in constitutional symptoms, and 4 (20%) had an objective response (improvement in peripheral cytopenias or spleen size). The degree of marrow fibrosis was unchanged, and only minor changes in overall marrow cellularity were observed. Toxicity was mild, with injection site reactions (20%) and minor infections (10%) as the most common side effects. One patient developed reversible pancytopenia. Etanercept may be useful for palliation of constitutional symptoms in MMM.

Reflections on nutritional issues associated with cancer therapy

PURPOSE

It is now recognized that dietitians have a significant role to play in the care of oncology patients, many of whom have problems with nutrition. However, it is increasingly understood that there are important obstacles to assisting patients with nutritional problems in the oncology setting. The purpose of this article is to discuss the incidental findings of two recent studies, highlighting the importance of and problems associated with nutritional issues in patients with a hematologic malignancy.

OVERVIEW

This article presents findings from two recent studies with a subset of patients who have hematologic malignancies. This diagnostic subgroup has specific challenges associated with nutrition and eating because of the intensive and aggressive treatments that patients endure. An explorative, descriptive, iterative, qualitative methodology was used for both studies. The focus was on exploring the lived experience of treatment in oncology/hematology for patients (prospective) and caregivers (retrospective).

CLINICAL IMPLICATIONS

The findings indicate that the issues surrounding food and eating are considered to be of great significance both to patients who are undergoing intensive treatment for a hematologic malignancy and to their caregivers. The significance of food is not seen purely in relation to its nutritional value, but as an important quality-of-life issue. Eating problems during intensive chemotherapy are perceived as highly stressful and can be, in the case of treatment-related anorexia, life threatening. Recommendations are made for interventions that could reduce the stress and nutritional difficulties for both patients and caregivers.

Cytokine stimulation of energy expenditure through p38 MAP kinase activation of PPARgamma coactivator-1

Cachexia is a chronic state of negative energy balance and muscle wasting that is a severe complication of cancer and chronic infection. While cytokines such as IL-1alpha, IL-1beta, and TNFalpha can mediate cachectic states, how these molecules affect energy expenditure is unknown. We show here that many cytokines activate the transcriptional PPAR gamma coactivator-1 (PGC-1) through phosphorylation by p38 kinase, resulting in stabilization and activation of PGC-1 protein. Cytokine or lipopolysaccharide (LPS)-induced activation of PGC-1 in cultured muscle cells or muscle in vivo causes increased respiration and expression of genes linked to mitochondrial uncoupling and energy expenditure. These data illustrate a direct thermogenic action of cytokines and p38 MAP kinase through the transcriptional coactivator PGC-1.

Metabolic responses to tumour disease and progression: tumour-host interaction

The progressive nutritional deterioration frequently found in cancer patients, is often referred to as cancer cachexia. In contrast to starvation, where it is possible to reverse the body composition changes by the provision of extra calories, in cancer cachexia this reversal is not observed, suggesting that anorexia alone is unlikely to be responsible for this wasting syndrome. Over the past decades a number of studies have focused on the possible mediators which may be responsible for metabolic abnormalities observed in cancer patients. Pro-inflammatory cytokines have been strongly implicated, but evidence supporting such a direct role is lacking. Recently, exciting work regarding molecules produced by tumour cells, and which may induce lipolysis and proteolysis, has been published. There is also evidence that increased metabolism of host resources may provide substrates which might promote tumour growth. A number of studies have demonstrated that polyunsaturated fatty acids, such as linoleic and arachidonic acid, are able to promote tumour cell growth either by directly stimulating mitosis or by inhibiting apoptosis. Even more interesting is the discovery of antagonists of these catabolic factors such as eicosapentanoic acid for the lipolytic factor, which may play a role in the treatment of these patients in the near future.