Hormonal and metabolic abnormalities in the malnourished cancer patient: effects on host-tumor interaction

Important aspects of nutrition in children with cancer

Adequate nutrition during cancer plays a decisive role in several clinical outcome measures, such as treatment response, quality of life, and cost of care. However, the importance of nutrition in children and young adults with malignancies is still an underestimated topic within pediatric oncology. The importance of our work is to reinforce and indicate that malnutrition in children with cancer should not be accepted at any stage of the disease or tolerated as an inevitable process. Unique to our manuscript is the close collaboration, the exchange of knowledge and expertise between pediatric oncologists and a nutritional specialist, as well as the comprehension of the mechanisms during cancer cachexia and malnutrition. We provide a critical review of the current state of research and new knowledge related to nutritional management in childhood cancer.

GLUT1 expression in malignant tumors and its use as an immunodiagnostic marker

OBJECTIVE

To analyze glucose transporter 1 expression patterns in malignant tumors of various cell types and evaluate their diagnostic value by immunohistochemistry.

INTRODUCTION

Glucose is the major source of energy for cells, and glucose transporter 1 is the most common glucose transporter in humans. Glucose transporter 1 is aberrantly expressed in several tumor types. Studies have implicated glucose transporter 1 expression as a prognostic and diagnostic marker in tumors, primarily in conjunction with positron emission tomography scan data.

METHODS

Immunohistochemistry for glucose transporter 1 was performed in tissue microarray slides, comprising 1955 samples of malignant neoplasm from different cell types.

RESULTS

Sarcomas, lymphomas, melanomas and hepatoblastomas did not express glucose transporter 1. Forty-seven per cent of prostate adenocarcinomas were positive, as were 29% of thyroid, 10% of gastric and 5% of breast adenocarcinomas. Thirty-six per cent of squamous cell carcinomas of the head and neck were positive, as were 42% of uterine cervix squamous cell carcinomas. Glioblastomas and retinoblastomas showed membranous glucose transporter 1 staining in 18.6% and 9.4% of all cases, respectively. Squamous cell carcinomas displayed membranous expression, whereas adenocarcinomas showed cytoplasmic glucose transporter 1 expression.

CONCLUSION

Glucose transporter 1 showed variable expression in various tumor types. Its absence in sarcomas, melanomas, hepatoblastomas and lymphomas suggests that other glucose transporters mediate the glycolytic pathway in these tumors. The data suggest that glucose transporter 1 is a valuable immunohistochemical marker that can be used to identify patients for evaluation by positron emission tomography scan. The function of cytoplasmic glucose transporter 1 in adenocarcinomas must be further examined.

The scientific rationale for optimizing nutritional support in cancer

Cancer patients lose weight as a result of the anorexia-cachexia syndrome, and this weight loss is associated with significant morbidity and mortality. Thus, nutritional support to arrest or reverse weight loss is of paramount importance in the management of Cachexia cancer patients. Persistent tumour-induced metabolic changes result, however, in a suboptimal response to such support, making nutritional maintenance or improvement difficult targets to achieve. Mechanisms involved in the blockade to anabolism in cancer cachexia include alterations in skeletal muscle and hepatic protein metabolism, and reduced physical activity. Mediators underlying these mechanisms of weight loss include proinflammatory cytokines, tumour-specific cachectic factors, and neuroendocrine mediators of muscle catabolism. The complex mix of different mediators renders unimodal nutritional intervention a strategy that is unlikely to succeed completely. Therefore, clinical trials using combination therapies or immunonutrition are required for future success.

A phase II study with antioxidants, both in the diet and supplemented, pharmaconutritional support, progestagen, and anti-cyclooxygenase-2 showing efficacy and safety in patients with cancer-related anorexia/cachexia and oxidative stress

PURPOSE

To test the efficacy and safety of an integrated treatment based on a pharmaconutritional support, antioxidants, and drugs, all given orally, in a population of advanced cancer patients with cancer-related anorexia/cachexia and oxidative stress.

PATIENTS AND METHODS

An open early-phase II study was designed according to the Simon two-stage design. The integrated treatment consisted of diet with high polyphenols content (400 mg), antioxidant treatment (300 mg/d alpha-lipoic acid + 2.7 g/d carbocysteine lysine salt + 400 mg/d vitamin E + 30,000 IU/d vitamin A + 500 mg/d vitamin C), and pharmaconutritional support enriched with 2 cans per day (n-3)-PUFA (eicosapentaenoic acid and docosahexaenoic acid), 500 mg/d medroxyprogesterone acetate, and 200 mg/d selective cyclooxygenase-2 inhibitor celecoxib. The treatment duration was 4 months. The following variables were evaluated: (a) clinical (Eastern Cooperative Oncology Group performance status); (b) nutritional [lean body mass (LBM), appetite, and resting energy expenditure]; (c) laboratory [proinflammatory cytokines and leptin, reactive oxygen species (ROS) and antioxidant enzymes]; (d) quality of life (European Organization for Research and Treatment of Cancer QLQ-C30, Euro QL-5D, and MFSI-SF).

RESULTS

From July 2002 to January 2005, 44 patients were enrolled. Of these, 39 completed the treatment and were assessable. Body weight increased significantly from baseline as did LBM and appetite. There was an important decrease of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha, and a negative relationship worthy of note was only found between LBM and IL-6 changes. As for quality of life evaluation, there was a marked improvement in the European Organization for Research and Treatment of Cancer QLQ-C30, Euro QL-5D(VAS), and multidimensional fatigue symptom inventory-short form scores. At the end of the study, 22 of the 39 patients were "responders" or "high responders." The minimum required was 21; therefore, the treatment was effective and more importantly was shown to be safe.

CONCLUSION

The efficacy and safety of the treatment have been shown by the study; therefore, a randomized phase III study is warranted.

The causes and consequences of cancer-associated malnutrition

Cancer-associated malnutrition can result from local effects of a tumour, the host response to the tumour and anticancer therapies. Although cancer patients often have reduced food intake (due to systemic effects of the disease, local tumour effects, psychological effects or adverse effects of treatment), alterations in nutrient metabolism and resting energy expenditure (REE) may also contribute to nutritional status. Several agents produced by the tumour directly, or systemically in response to the tumour, such as pro-inflammatory cytokines and hormones, have been implicated in the pathogenesis of malnutrition and cachexia. The consequences of malnutrition include impairment of immune functions, performance status, muscle function, and quality of life. In addition, responses to chemotherapy are decreased, chemotherapy-induced toxicity and complications are more frequent and severe, and survival times are shortened. Depression, fatigue and malaise also significantly impact on patient well-being. In addition, cancer-related malnutrition is associated with significant healthcare-related costs. Nutritional support, addressing the specific needs of this patient group, is required to help improve prognosis, and reduce the consequences of cancer-associated nutritional decline.

Common symptoms in advanced cancer

The key points of this article are anorexia and cachexia are: A major cause of cancer deaths. Several drugs are available to treat anorexia and cachexia. Dyspnea in cancer usually is caused by several factors. Treatment consists of reversing underlying causes, empiric bronchodilators, cortico-steroids--and in the terminally ill patients-opioids, benzodiazepines,and chlorpromazine. Delirium is associated with advanced cancer. Empiric treatment with neuroleptics while evaluating for reversible causes is a reasonable approach to management. Nausea and vomiting are caused by extra-abdominal factors (drugs,electrolyte abnormalities, central nervous system metastases) or intra-abdominal factors (gastroparesis, ileus, gastric outlet obstruction, bowel obstruction). The pattern of nausea and vomiting differs depending upon whether the cause is extra- or intra-abdominal. Reversible causes should be sought and empiric metoclopramide or haloperidol should be initiated. Fatigue may be caused by anemia, depression, endocrine abnormalities,or electrolyte disturbances that should be treated before using empiric methylphenidate. Constipation should be treated with laxatives and stool softeners. Both should start with the first opioid dose.

What is the role of the insulin-like growth factor system in the pathophysiology of cancer cachexia, and how is it regulated?

OBJECTIVE AND BACKGROUND

The cancer cachexia syndrome is characterized by anorexia, weight loss with muscle wasting and increased energy expenditure. It is associated with increased morbidity and mortality, but its aetiology is poorly understood and no effective therapeutic intervention is available. It may result from an imbalance between the activity or effect of anabolic and catabolic hormones, mediated by the inflammatory cytokines. IGF-I is a potent anabolic agent, with therapeutic potential. Our objective was to investigate the role and regulation of the IGF system in cancer cachexia.

DESIGN AND PATIENTS

We set up a prospective study of 30 patients with newly diagnosed unresectable non-small cell lung cancer, together with a cross-sectional comparison group of healthy volunteers.

MEASUREMENTS

We examined the relationship between aspects of the IGF system, including IGFBP-3 proteolysis (using Western ligand and immunoblotting and an in vitro IGFBP-3 protease assay); the inflammatory cytokines and their soluble receptors; and food intake and nutritional status (including biochemical and anthropometric assessments).

RESULTS

Although we did not observe a marked reduction in food intake in the cancer patients, the majority lost weight and functionally important lean body mass. We observed GH resistance in the cancer patients, and intermittent proteolysis of IGFBP-3, which correlated with the circulating interleukin-6 (IL-6) concentration. The pattern of IGFBP-3 proteolysis was unusual, with a prominent 17-kDa fragment. Less IGFBP-3 proteolysis was associated with more weight loss, suggesting that this could be a protective counter-regulatory mechanism, increasing IGF-I bioavailability to the tissues.

CONCLUSIONS

Cancer cachexia in humans is a complex condition. Patients tend to be GH resistant. The significance of the intermittent increases in IGFBP-3 proteolysis, which may be regulated by IL-6, remains uncertain. A better understanding of the pathophysiology should enable the development of novel therapeutic approaches.

Effects of social housing condition on chemotherapeutic efficacy in a Shionogi carcinoma (SC115) mouse tumor model: influences of temporal factors, tumor size, and tumor growth rate

OBJECTIVE

The objective of this study was to investigate 1) whether social housing condition, tumor size, and tumor growth rate alter responses to chemotherapy and 2) whether the timing of tumor cell injection or chemotherapy initiation (relative to housing condition formation) influences tumor growth rate or the efficacy of chemotherapy.

METHODS

Mice were reared individually (I) or in groups (G). In experiment 1, mice were rehoused (IG or GI) or left in group housing (GG) immediately after tumor cell injection. In experiment 2, housing conditions (II, IG, GG, or GI) were formed when tumors weighed 1 g. Chemotherapy (adriamycin 4 mg/kg and cyclophosphamide 61.5 mg/kg IP) and exposure to acute novelty stress (15 min/d, 5 d/wk) were initiated 1 day after housing condition formation.

RESULTS

If chemotherapy was initiated when the tumor burden was undetectable (experiment 1), housing condition did not alter tumor response to chemotherapy, although IG mice lost the most weight and overall had the lowest probability of survival. If chemotherapy was initiated when tumors weighed 1 g (experiment 2), both tumor and host responses to chemotherapy were poorest for IG mice. Timing of tumor cell injection relative to housing condition formation also differentially influenced the rate of tumor growth in mice treated with the drug vehicle; in experiment 1, tumor growth rate was faster in GI and GG mice than in IG mice, whereas in experiment 2, the rate of tumor growth was faster in II mice than in GG and IG mice.

CONCLUSIONS

Altering the temporal relationships among social housing condition formation, tumor cell injection, and chemotherapy initiation differentially influences the rate of tumor growth and the efficacy of chemotherapy. Effects of housing condition are independent of tumor growth rate at chemotherapy initiation and, in terms of host responses, independent of tumor burden.

Dietary intake and resting energy expenditure in relation to weight loss in unselected cancer patients

Weight loss and anorexia are frequent findings in advanced cancer. The progressive wasting could be attributed to changes in dietary intake and/or energy expenditure mediated by metabolic alterations. In this study, we analyzed dietary intake in generalized malignant disease of solid tumor type in relation to resting energy expenditure (REE) and reported weight loss. In a group of 297 unselected cancer patients from a university hospital outpatient clinic, dietary intake of energy and macronutrients from a 4-day food record, REE by indirect calorimetry, height, weight and weight loss were recorded. Protein intake was validated against 24 hr urine nitrogen in a subgroup (n = 53), and no indication of systematic misreporting was found. Mean daily dietary intake was below maintenance requirements, 26 +/- 10 kcal/kg. Weight loss of more than 10% was present in 43% of patients and elevated REE (>110% of predicted) in 48%. Dietary intake did not differ between normo- and hypermetabolic patients, nor was tumour type or gender related to energy and protein intake. Weight loss could not be accounted for by diminished dietary intake since energy intake in absolute amounts was not different and intake per kilogram body weight was higher in weight-losing patients compared to weight-stable patients. Dietary macronutrient composition did not differ from the general population. Dietary intake of energy and protein was decreased, but dietary macronutrient composition did not appear to be changed. Weight loss and hypermetabolism were frequent and not compensated for by an increase in spontaneous food intake. Our results indicate that an expected up-regulation of dietary intake in response to elevated energy expenditure is frequently lost in cancer patients. This may be the explanation behind cancer cachexia rather than a primary decrease in appetite.

Pathophysiology of cancer cachexia

Cancer cachexia is a frequent complication observed in patients with malignant tumors. Although several decades have passed since the first focus on the metabolic dysfunction's associated with cancer, few effective therapeutic interventions have been successfully introduced into the medical armamentarium. The present study thoroughly reviews the basic pathophysiology of cancer cachexia and the treatment options already investigated in that field. Experimental and clinical studies were evaluated individually in order to clarify the intricate alterations observed in tumor-bearing patients. The difficulties in introducing sound and effective nutritional support or metabolic manipulation to reverse cancer cachexia are outlined in this review.

A new model of cancer cachexia: contribution of the ubiquitin-proteasome pathway

A new model of cachexia is described in which muscle protein metabolism related to the ubiquitin-proteasome pathway was investigated. Cloning of the colon-26 tumor produced a cell line, termed R-1, which induced cytokine (noninterleukin-1beta, interleukin-6 and tumor necrosis factor-alpha)-independent cachexia. Implantation of R-1 cells in mice elicited significant (20-30%) weight loss and decreased blood glucose by 70%, and adipose tissue levels declined by 95% and muscle weights decreased by 20-25%. Food intake was unaffected. The decrease in muscle weight reflected a decline in insoluble, but not soluble, muscle protein that was associated with a significant increase in net protein degradation. The rate of ubiquitin conjugation of proteins was significantly elevated in muscles of cachectic mice. Furthermore, the proteasome inhibitor lactacystin blocked the increase in protein breakdown but had no significant effect on proteolysis. Several markers of the ubiquitin-proteasome pathway, E2(14k) mRNA and E2(14k) protein and ubiquitin-protein conjugates, were not elevated. Future investigations with this new model should gain further insights into the mechanisms of cachexia and provide a background to evaluate novel and more efficacious therapies.

Malnutrition associated with HIV/AIDS. Part One: Definition and scope, epidemiology, and pathophysiology

A documented association exists between nutritional status and immunologic function, development, and outcome of infectious processes, and treatment-related toxicity and vital organ function. In persons with AIDS, nutritional deficits precipitate a cycle that results in a downward spiral of weight lost, malabsorption, diarrhea, anorexia, body image disturbance, and increased risk for morbidity and mortality. This article presents an overview of the malnutrition in HIV/AIDS patients. It critiques the current Centers for Disease Control's definitions of wasting syndrome, describes the incidence of weight loss, delineates the implications of untreated malnutrition, and traces the etiology of weight loss and contributing factors. This article serves as an introduction to HIV/AIDS related malnutrition. A subsequent article will review nursing implications and clinical management programs.

Implementing a ketogenic diet based on medium-chain triglyceride oil in pediatric patients with cancer

Traditionally, a ketogenic diet is given to drug-resistant children with epilepsy to improve seizure control. Inducing a ketogenic state in patients with cancer may be a useful adjunct to cancer treatment by affecting tumor glucose metabolism and growth while maintaining the patient's nutritional status. A ketogenic diet consisting of 60% medium-chain triglyceride (MCT) oil, 20% protein, 10% carbohydrate, and 10% other dietary fats was provided to a select group of pediatric patients with advanced-stage cancer to test the effects of dietary-induced ketosis on tumor glucose metabolism. Issues of tolerance and compliance for patients consuming an oral diet (consisting of normal table foods and daily MCT oil "shakes") and for patients receiving an enteral formula are reviewed. Preliminary use of the MCT oil-based diet suggests a potential in pediatric patients with cancer.

Expression of glucose transporters in head-and-neck tumors

The expression of glucose transporter genes (GLUTI-4) was studied in 20 head-and-neck tumors of 18 patients. All tumors--16 of which were squamous-cell carcinomas (SCC)--expressed GLUT1 and/or GLUT3 mRNA, while detectable levels of GLUT2 or GLUT4 mRNA were not observed. The signals for GLUT1 and GLUT3 mRNAs varied markedly throughout the SCC tumor population but no clear relationship with the grade of differentiation was found. The high GLUT expression observed in some tumors was not associated with amplification or rearrangement of the corresponding genes. Immunohistochemistry of 5 SCCs showed that GLUT1 protein was located in tumor-cell membranes in relation to the level of mRNA expression. We conclude that both GLUT1 and GLUT3 are involved in basal glucose uptake of extracranial head-and-neck tumors. The increased expression of these high-affinity GLUT isoforms may be related to the growth maintenance of cancer tissue in cases of limited supply of substrate e.g., in poorly vascularized tumor areas.

Lack of significant changes in nutrition-related parameters with tumor necrosis factor treatment of cancer

Cancer and its therapies frequently produce anorexia and cachexia. In this study, the acute (3 days) and chronic (4 wks) nutrition-related effects of cancer therapy with recombinant human tumor necrosis factor (rHuTNF) were investigated and described. Nutritional status, as measured by body weight and body composition (body fat and lean-to-fat ratio) with use of bioelectrical impedance, did not appear to deteriorate. None of the serum lipids changed significantly, but triglycerides did rise modestly over four weeks of therapy. Glucose and the peptide hormones (insulin, C-peptide, glucagon, and pancreatic polypeptide) thought to affect appetite did not change with rHuTNF therapy. Therefore, although TNF is thought to contribute to wasting in animal models, it had no negative effect on nutritional status in our small sample. The lack of adverse effect noted in this study is possibly due to the low dose level of rHuTNF or to adaptation.