Tumor host relations. I. Increased plasma cortisol in tumor-bearing humans compared with patients with benign surgical diseases

Nutrition Modulation of Cachexia/Proteolysis

Cachexia represents progressive wasting of muscle and adipose tissue and is associated with increased morbidity and mortality. Although anorexia usually accompanies cachexia, cachexia rarely responds to increased food intake alone. Our knowledge of the underlying mechanisms responsible for cachexia remains incomplete. However, most states of cachexia are associated with underlying inflammatory processes and/or cancer. These processes activate protein degradation and lipolytic pathways, resulting in tissue loss. In this article, we briefly review the pathophysiology of cachexia and discuss the role of specific nutrient supplements for the treatment of cachexia. The branched chain amino acid leucine, the leucine metabolite beta-hydroxy-beta-methylbutyrate, arginine, glutamine, omega-3 long chain fatty acids, conjugated linoleic acid, and polyphenols have demonstrated some efficacy in animal and/or human studies. Optimal treatment for cachexia is likely aimed at maximizing muscle and adipose synthesis while minimizing degradation.

Cancer cachexia update in head and neck cancer: Pathophysiology and treatment

The pathophysiology of cancer cachexia remains complex. A comprehensive literature search was performed up to April 2013 using PubMed, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, and the Google search engine. In this review, we focus on the different mediators of impaired anabolism and upregulated catabolism that alter the skeletal muscle homeostasis resulting in the wasting of cancer cachexia. We present recent evidence of targeted treatment modalities from clinical trials along with their potential mechanisms of action. We also report on the most current evidence from randomized clinical trials using multimodal treatments in patients with cancer cachexia, but also the evidence from head and neck cancer-specific trials. A more complete understanding of the pathophysiology of the syndrome may lead to more effective targeted therapies and improved outcomes for patients.

Cancer cachexia: developing multimodal therapy for a multidimensional problem

Cancer cachexia is a multi-factorial syndrome that encompasses a spectrum from early weight loss (pre-cachexia) to a state of severe incapacity incompatible with life. The molecular basis of the syndrome in animal models (based on host-tumour cell interaction, the neuro-hormonal control of appetite and the hypertrophy/atrophy pathways that govern muscle-wasting) has provided a new raft of biomarkers and therapeutic targets. Key defining features of cachexia in humans (weight loss, reduced food intake and systemic inflammation) now provide not only a framework for classification but also a rationale for targets for therapeutic intervention. The role of age and immobility in muscle-wasting also provides a rationale for the nature of nutritional support in cachexia. There is now a substantive evidence that multimodal approaches that address these key issues can stabilise and even improve the nutritional status, function and quality of life of at least a proportion of advanced cancer patients. Novel biomarkers for patient stratification and more specific techniques for the estimation of muscle mass and physical activity level herald a new era in trial design. The current evidence-base justifies new enthusiasm for the design of complex intervention studies in the management of cancer cachexia.

Biomarkers for cancer cachexia: is there also a genetic component to cachexia?

INTRODUCTION

Cancer cachexia is a severe debilitating disorder, which causes significant morbidity and mortality. In clinical practice, cachexia is often not treated until a late stage, when therapeutic options are limited.

OBJECTIVE

It is therefore of great interest to analyse early biomarkers of this syndrome.

CONCLUSION

In this review article, we summarise recent biomarkers found in various body compartments. We also explore the likelihood of a genetic predisposition to cachexia and focus on the potential role of single nucleotide polymorphisms in genes coding for pro- and anti-inflammatory cytokines, and 'atrogenes' associated with wasting in skeletal muscle.

Glucocorticoids, metabolism and metabolic diseases

Since the discovery of the beneficial effects of adrenocortical extracts for treating adrenal insufficiency more than 80 years ago, glucocorticoids (GC) and their cognate, intracellular receptor, the glucocorticoid receptor (GR) have been characterized as critical components of the delicate hormonal control system that determines energy homeostasis in mammals. Whereas physiological levels of GCs are required for proper metabolic control, excessive GC action has been tied to a variety of pandemic metabolic diseases, such as type II diabetes and obesity. Highlighted by its importance for human health, the investigation of molecular mechanisms of GC/GR action has become a major focus in biomedical research. In particular, the understanding of tissue-specific functions of the GC-GR pathway has been proven to be of substantial value for the identification of novel therapeutic options in the treatment of severe metabolic disorders. Therefore, this review focuses on the role of the GC-GR axis for metabolic homeostasis and dysregulation, emphasizing tissue-specific functions of GCs in the control of energy metabolism.

Symptoms in advanced cancer: relationship to endogenous cortisol levels

We investigated a possible relationship between levels of endogenous cortisol and severity of different symptoms in patients with advanced cancer. Twenty-three patients with predominantly gastrointestinal cancer, recruited in a palliative care unit, entered the study. Urinary free cortisol (UFC) was measured together with demographic data, blood parameters, tumour burden, concurrent illness, medication, nutritional status and quality of life. Significant positive correlations were found between levels of endogenous cortisol and appetite loss, fatigue and nausea/vomiting. The findings support the view of a chronic stress condition in advanced cancer. Interaction between cytokines and the hypothalamic-pituitary-adrenal (HPA) axis may also be important in the interpretation of the results.

Cancer cachexia

Cancer cachexia is a complex, multifactorial syndrome that results from a reduction in food intake, a variety of metabolic abnormalities (including hypermetabolism) or more often a combination of the two. Multiple mediator pathways including pro-inflammatory cytokines, neuroendocrine hormones and tumour-specific factors are involved. Therapy requires a multi-model approach that addresses both reduced food intake and metabolic change. Combination treatments such as nutritional support plus metabolic/inflammation modulation promise improved functional capacity and quality of life.

Cancer cachexia and its treatment with fish-oil-enriched nutritional supplementation

OBJECTIVE

Cachexia is a common condition affecting those with advanced cancer. This review explores mechanisms of cachexia and possible treatments devised with these mechanisms in mind.

METHODS

Selective review of the relevant scientific literature was performed with particular emphasis on studies performed by our group over the past 10 y involving patients with advanced pancreatic cancer.

RESULTS

Cancer cachexia adversely affects patient quality of life and survival. It is characterized by a lack of a normal anabolic response to the provision of apparently adequate nutrition. It appears to result from a persistent response to illness stimulated by the cancer resulting in a proinflammatory cytokine and catabolic hormonal environment. Interventions that ignore this inflammatory milieu have had little success. More promising interventions have a broad antiinflammatory component such as nonsteroidal antiinflammatory drugs or fish oil. Preliminary studies of a combination of fish oil as an antiinflammatory agent with nutritional supplementation show promise in reversing weight loss with apparent gains in lean tissue and performance status in association with normalization of the metabolic environment in patients with advanced pancreatic cancer.

CONCLUSIONS

Cancer cachexia produces a metabolic environment that prevents the appropriate use of supplied nutrition. Antiinflammatory agents such as fish oil in combination with nutritional supplementation may reverse aspects of cachexia.

Cancer cachexia

Cachexia is a common cause of morbidity and mortality in patients with advanced cancer. It is characterised by numerous metabolic abnormalities including inefficient substrate utilisation, alterations in the balance of energy intake and expenditure and the acute-phase protein response. These changes seem to be driven by pro-inflammatory cytokines, alterations of the neuro-endocrine axis and tumour-derived catabolic factors. This results in the loss of both fat and lean tissue. Trials of conventional nutritional supplements in patients with cancer cachexia have failed to show any benefit in terms of weight gain or quality of life and this may be because the ongoing metabolic abnormalities prevent the efficient use of additional calories supplied. A variety of pharmacological agents have been studied in an attempt to normalise these metabolic changes with only limited success. However, it is possible that the combination of an agent to normalise the metabolic milieu along with the provision of additional nutritional support may have the potential to reverse cachexia in advanced cancer.

Metabolic response to chemotherapy in colon cancer patients

The goal of this investigation was to identify the metabolic abnormalities in a group of colon cancer patients before and during 5-fluorouracil chemotherapy. Twenty-two colon cancer patients were prospectively enrolled into a Clinical Research Center for measurement of counter regulatory hormones, fasting hepatic glucose production (HGP), intravenous glucose tolerance test, plasma leucine appearance (LA), and leucine oxidation (LO). Both the cancer group and the normal volunteers were matched for nutrition status (109 +/- 5% of ideal body weight vs 104 +/- 4%, mean +/- SEM, respectively) and history of weight loss (6.3 +/- 2.6 kg vs 4.4 +/- 4.8). Plasma growth hormone was significantly elevated in the colon cancer patients (3.22 +/- 0.62 ng/mL vs 0.73 +/- 0.18, p < .05) despite the fact that insulin-like growth factor-1 levels were not different. Plasma glucose, insulin, cortisol, glucagon, epinephrine, and norepinephrine levels were not significantly different than those of the normal volunteers. Fasting HGP rates were slightly but not significantly elevated in the group of colon cancer patients compared with the normal volunteers (2.09 +/- 0.11 mg/kg per minute vs 1.79 +/- 0.10, p = .10). Plasma LA was not significantly elevated in the colon cancer group (63.3 +/- 3.0 mumol/kg per hour vs 57.7 +/- 4.2; p = .25). Five days of continuous 5-fluorouracil chemotherapy was associated with a significant elevation in both the fasting glucose level (97 +/- 3 mg/dL vs 106 +/- 5, p < .05), and HGP (2.09 +/- 0.11 mg/kg per minute vs 2.27 +/- 0.10; p < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Nutritional and metabolic effects of gonadotropin-releasing hormone agonist treatment for prostate cancer

Cancer commonly leads to weight loss associated with increased glucose production and protein breakdown. Medical or surgical castration results in decreased muscle mass, increased fat mass, and weight gain. The aim of this study was to evaluate the changes in body composition, protein metabolism, hepatic glucose production, (HGP), and basal energy expenditure in 10 men with advanced stage C and D prostate cancer receiving a gonadotropin-releasing hormone (GnRH) agonist (Buserelin). Metabolic parameters and nutritional status were determined at 0, 2, 6, and 12 months of therapy. Baseline measurements of plasma leucine appearance (76.2 +/- 5.4 microM/kg/h) and HGP rates (80.1 +/- 2.9 mg/m2/min) were greater than previously reported for normal volunteers. GnRH agonist therapy in prostate cancer patients was associated with a significant reduction in serum testosterone, dihydrotestosterone (DHT), luteinizing hormone (LH), and cortisol, and significant increases in triiodothyronine (T3) and free triiodothyronine (free T3). Neither basal energy expenditure nor plasma leucine appearance rates were changed over time, but there were significant linear reductions in HGP rates (80.1 +/- 2.9 mg/m2/min, mean +/- SEM; 79.9 +/- 2.3, 73.7 +/- 3.4, 72.5 +/- 2.3; P less than .01; baseline, 2, 6, and 12 months, respectively, by repeated measures ANOVA). In all patients, significant increases in body weight, triceps skin fold, cholesterol, and fat mass were noted. Total body water content was not significantly increased after the 12-month period; therefore, the weight gain seen in these patients was water-free tissue, ie, fat mass.

Glucose uptake and amino acid metabolism in perfused hearts from tumor-bearing rats

The purpose of this study was to evaluate whether heart glucose metabolism can account for elevated heart oxygen consumption in a tumor-bearing host. This is the first report of altered metabolism in perfused hearts from tumor-bearing animals. Glucose, glycerol, lactate, and amino acid metabolism was examined under steady-state conditions in isolated perfused hearts from sarcoma-bearing rats and compared to the metabolism in hearts from starved (96 hr) and fed control rats. Heart dry weight was reduced by 10% in tumor-bearing rats and by 30% in starved rats when compared to freely fed control animals. Cardiac glucose uptake was decreased in tumor-bearing rats (206 +/- 33 mumoles/hr/g dry wt) compared to both starved (298 +/- 18) and fed control rats (293 +/- 25). Hearts from both fed and starved controls released lactate and glycerol at significant rates during perfusion which was not evident in hearts from tumor-bearing rats. The release of individual amino acids from working hearts during perfusion was different among the animal groups with a severe depression of both glutamine and alanine release in tumor-bearing rats. In starved rats alanine release was normal although glutamine release was depressed by more than 50%. The net release of all amino acids was lowest in hearts from tumor-bearing rats, intermediate in the starved animals, and highest in the control animals, while the nonmetabolized amino acids (phenylalanine, tyrosine, methionine) were released at increased rates only from tumor-host hearts, indicating an increased net breakdown of some cardiac proteins in tumor-bearing animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased urinary excretion of cortisol and catecholami-NES in malnourished cancer patients

Excretion of cortisol and catecholamines were measured from 24-hour urine samples collected over a period of 3 days from hospitalized cancer patients suffering from malnutrition and were compared with those of control patients equally malnourished and having a similar degree of inflammation. Compared with control patients, cancer patients had a higher excretion of cortisol, adrenaline, and noradrenaline, although noradrenaline excretion reached statistical significance only when normalized to creatinine excretion. Plasma glycerol concentrations after an overnight fast were significantly higher in cancer patients as compared with control patients, in keeping with an increased adrenal and adrenergic activity. This study demonstrates evidence of simultaneously elevated catecholamine and cortisol excretion in cancer patients, which could not be ascribed to alteration in body composition. The results may, in part, explain the mechanisms behind ongoing tissue breakdown in progressive cancer disease.

Protein synthesis in hepatocytes isolated from patients with gastrointestinal malignancy

To investigate the effect of remote and proximate cancer on hepatic protein metabolism, we determined rates of total protein synthesis by hepatocytes (HPS) isolated from 31 patients undergoing liver wedge biopsy: 7 patients with benign disease, 14 with gastric cancer, and 10 with colorectal cancer (5 of whom had liver metastases). Patients with malignant disease without weight loss had a threefold higher rate of total HPS (4,980 +/- 814 pmol/h per 10(5) viable cells) than patients with benign disease without weight loss (1,278 +/- 318 pmol/h per 10(5) viable cells, P less than 0.001). Among the patients with gastric cancer, eight with preoperative weight loss had lower rates of HPS (380 +/- 90 pmol/h per 10(5) viable cells) than those without weight loss (4,061 +/- 401 pmol/h per 10(5) viable cells, P less than 0.002). The highest rates of HPS were seen in patients with colorectal cancer with liver metastases (8,005 +/- 1,975 pmol/h per 10(5) viable cells) vs. colorectal cancer patients without liver metastases (3,060 +/- 575 pmol/h per 10(5) viable cells, P less than 0.03). These data indicate that modulation of hepatic protein synthesis occurs in malignancy in man. However, the stimulatory influence of the tumor-bearing state may be overridden by the inhibitory effects of cachexia.

Endocrinology of breast cancer

Oestrogen predominance over progesterone may cause hyperproliferation of mammary epithelium and thus promote breast carcinogenesis. In patients with a hormone-dependent tumour, oestrogens may also accelerate cancer growth. Conversely, they may inhibit tumour growth in patients with an oestrogen receptor-negative carcinoma which has grown in an oestrogen-poor environment. Progesterone opposes oestrogen-induced epithelial proliferation and causes cellular differentiation with decreased mitosis, thus reducing the risk of breast cancer. Prolactin brings about mammary epithelial differentiation for secretory function; in the lactation state, epithelial proliferation is minimal. The role of androgens, melatonin, thymosin, metabolic hormones (growth hormone, thyroid hormone(s), insulin, glucocorticosteroids) and prostaglandins in the pathobiology of breast cancer is poorly understood. A breast cancer population consists of individuals in whom more than 20 different tumour subsets may be present, i.e. patients with different individual tumour pathobiology and endocrinology patterns and therefore different prognoses. Progress in the endocrinology of breast cancer seems possible through prospective studies in which hormones are determined in normal breast tissue (ductal fluid, cyst fluid) and then related to the corresponding concentrations in the plasma and urine of patients who develop breast cancer and those who do not. In addition, genetic and nonhormonal risk factors for breast cancer must be taken into consideration to define the endocrinological aspects involved.

Cancer cachexia

Cancer cachexia is a complex syndrome that includes host tissue wasting, anorexia, asthenia, and abnormal host intermediary metabolism. It is present in approximately 50% of cancer patients during treatment and nearly 100% of treated cancer patients at death. Cachexia has a detrimental impact on cancer therapy. The central problem of cancer cachexia is that energy balance is not maintained, and the host has a relative hypophagia which results in host tissue wasting. The tumor by its nature and obligate growth can continue to consume glucose, amino acids, and lipids at the expense of the host. This produces abnormal host intermediary metabolism including elevated glucose production and recycling, decreased muscle protein synthesis, and increased muscle and fat breakdown. The exact mechanisms of cancer cachexia have been only partially elucidated. The identification of signal molecules like cachectin which mediate these changes may be on the horizon. Nutritional support can reverse some of the derangements seen with cachexia, and there is evidence that functional lean body mass or body cell mass can be restored in some (but not all) patients. However, nutritional support has not yet improved response to chemotherapy or radiation therapy, nor has it improved host tolerance of chemotherapy. It has improved operative mortality and morbidity in cachectic cancer patients undergoing major surgical procedures. Optimum host nutritional support appears to be dependent on high insulin concentrations in both humans and rats. Insulin and exercise may be methods to preserve host lean tissue and feed the host rather than the tumor. Future studies depend on better definition of tumor-bearing host metabolism, altering the relationship between neoplasm and host to preferentially feed the host, and making the neoplasm more susceptible to effective treatment.