Effect of enteral and parenteral nutrition on amino acid levels in cancer patients

A European survey on the practice of nutritional interventions in head-neck cancer patients undergoing curative treatment with radio(chemo)therapy

PURPOSE

As the practice of nutritional support in patients with head and neck cancer (HNC) during curative radio(chemo)therapy is quite heterogeneous, we carried out a survey among European specialists.

METHODS

A 19-item questionnaire was drawn up and disseminated via the web by European scientific societies involved in HNC and nutrition.

RESULTS

Among 220 responses, the first choice was always for the enteral route; naso-enteral tube feeding was preferred to gastrostomy in the short term, while the opposite for period longer than 1 month. Indications were not solely related to the patient's nutritional status, but also to the potential burden of the therapy.

CONCLUSION

European HNC specialists contextualize the use of the nutritional support in a comprehensive plan of therapy. There is still uncertainty relating to the role of naso-enteral feeding versus gastrostomy feeding in patients requiring < 1 month nutritional support, an issue that should be further investigated.

Metabolic profiling of organic and fatty acids in chronic and autoimmune diseases

Metabolomics is a powerful tool of omics that permits the simultaneous identification of metabolic perturbations in several autoimmune and chronic diseases. Several parameters can affect a metabolic profile, from the population characteristics to the selection of the analytical method. In the current chapter, we summarize the main analytical methods and results of the metabolic profiling of fatty and organic acids performed in human metabolomic studies for asthma, COPD, psoriasis and Hashimoto's thyroiditis. We discuss the most significant metabolic alterations associated with these diseases, after comparison of either a single patient's group with healthy controls or several patient's subgroups of different disease severity and phenotype with healthy controls or of a patient's group before and after treatment. Finally, we present critical metabolic patterns that are associated with each disease and their potency for the unraveling of disease pathogenesis, prediction, diagnosis, patient stratification and treatment selection.

Nutritional interventions in elderly gastrointestinal cancer patients: the evidence from randomized controlled trials

Literature concerning nutritional interventions in elderly patients with gastrointestinal cancer, with special reference to randomized clinical trials, has been critically reviewed. This segment of oncologic population was found to be penalized by a high prevalence of malnutrition and sarcopenia which translated in an increased rate of toxicity from chemotherapy, poor compliance with oncologic treatments, and, finally, with a poor prognosis. Attempts to reverse this condition included a potentiation of nutrients intake which should sequentially proceed through the use of dietary counseling and administration of standard or ω-3 fatty acid-enriched oral supplements to finally come to enteral or parenteral nutrition. Randomized clinical trials investigating the effects of simple dietary advice and use of standard oral supplements were disappointing as regards long-term compliance and results. Nutritional and clinical benefits were reported with the use of ω-3 fatty acid-enriched oral supplements and especially with long-term supplemental parenteral nutrition. Despite the general recommendation of the scientific community that emphasizes the use of the enteral route, whenever possible, for delivering the nutritional support, it appears from the literature that more consistent benefits can be achieved, especially in the long-term nutritional support, when an insufficient oral nutrition is partnered with intravenous nutrition.

Palliative enteral feeding for patients with malignant esophageal obstruction: a retrospective study

BACKGROUND

Malignant esophageal obstruction leads to dysphagia, deterioration in quality of life, and malnutrition. Traditional bedside nasogastric (NG) tube placement is very difficult under these circumstances. However, endoscopically assisted NG tube placement under fluoroscopic guidance could be an alternative option for establishing palliative enteral nutrition. This study aimed to compare the clinical outcomes of enteral tube feeding and esophageal stenting for patients with malignant esophageal obstruction and a short life expectancy.

METHODS

Thirty-one patients were divided into 3 groups according to their treatment modality: NG tube (n = 12), esophageal stent group (n = 10), and supportive care with nil per os (NPO) (n = 9). Enteral nutrition, clinical outcomes, length of hospital stay, and median survival were evaluated.

RESULTS

There were no significant baseline differences among the groups, except in age. The tube and stent groups had significantly higher enteral calorie intake (p = 0.01), higher serum albumin (p < 0.01), shorter hospital stay (p = 0.01), and longer median survival (p < 0.01) than the NPO group. The incidence of dislodgement in the tube group was significantly higher than in the stent group (58% vs. 20%, respectively; p = 0.01). However, stenting costs more than NG tube placement.

CONCLUSIONS

Palliative enteral feeding by NG tube is safe, inexpensive, and has a low complication rate. Endoscopically assisted NG tube placement under fluoroscopic guidance could be a feasible palliative option for malignant esophageal obstruction for patients who have a short life expectancy.

Nutritional/metabolic response in older cancer patients

The combination of age-related muscle loss (sarcopenia) and the diagnosis of cancer (and the onset of cachexia) is likely a metabolic challenge that skeletal muscle of older cancer patients is not prepared to handle. Albeit to a smaller extent than healthy older controls, the skeletal muscle of older cancer patients is still acutely anabolic to the provision of amino acids. To provide an anabolic stimulus to skeletal muscle during a time when it is susceptible to an advanced rate of breakdown due to cancer- and tumor-related factors, enhanced intake of protein and amino acid sources might be necessary and should likely be higher than the current US recommended daily intake of 0.8 g protein/kg body weight/day. Future studies should investigate whether the acute effects of amino acids on muscle protein anabolism can be sustained over a longer period of time in the presence of cancer cachexia in older patients.

LC-MS metabolomics of psoriasis patients reveals disease severity-dependent increases in circulating amino acids that are ameliorated by anti-TNFα treatment

Psoriasis is an immune-mediated highly heterogeneous skin disease in which genetic as well as environmental factors play important roles. In spite of the local manifestations of the disease, psoriasis may progress to affect organs deeper than the skin. These effects are documented by epidemiological studies, but they are not yet mechanistically understood. In order to provide insight into the systemic effects of psoriasis, we performed a nontargeted high-resolution LC–MS metabolomics analysis to measure plasma metabolites from individuals with mild or severe psoriasis as well as healthy controls. Additionally, the effects of the anti-TNFα drug Etanercept on metabolic profiles were investigated in patients with severe psoriasis. Our analyses identified significant psoriasis-associated perturbations in three metabolic pathways: (1) arginine and proline, (2) glycine, serine and threonine, and (3) alanine, aspartate, and glutamate. Etanercept treatment reversed the majority of psoriasis-associated trends in circulating metabolites, shifting the metabolic phenotypes of severe psoriasis toward that of healthy controls. Circulating metabolite levels pre- and post-Etanercept treatment correlated with psoriasis area and severity index (PASI) clinical scoring (R² = 0.80; p < 0.0001). Although the responsible mechanism(s) are unclear, these results suggest that psoriasis severity-associated metabolic perturbations may stem from increased demand for collagen synthesis and keratinocyte hyperproliferation or potentially the incidence of cachexia. Data suggest that levels of circulating amino acids are useful for monitoring both the severity of disease as well as therapeutic response to anti-TNFα treatment.

ESPEN Guidelines on Parenteral Nutrition: non-surgical oncology

Parenteral nutrition offers the possibility of increasing or ensuring nutrient intake in patients in whom normal food intake is inadequate and enteral nutrition is not feasible, is contraindicated or is not accepted by the patient. These guidelines are intended to provide evidence-based recommendations for the use of parenteral nutrition in cancer patients. They were developed by an interdisciplinary expert group in accordance with accepted standards, are based on the most relevant publications of the last 30 years and share many of the conclusions of the ESPEN guidelines on enteral nutrition in oncology. Under-nutrition and cachexia occur frequently in cancer patients and are indicators of poor prognosis and, per se, responsible for excess morbidity and mortality. Many indications for parenteral nutrition parallel those for enteral nutrition (weight loss or reduction in food intake for more than 7-10 days), but only those who, for whatever reason cannot be fed orally or enterally, are candidates to receive parenteral nutrition. A standard nutritional regimen may be recommended for short-term parenteral nutrition, while in cachectic patients receiving intravenous feeding for several weeks a high fat-to-glucose ratio may be advised because these patients maintain a high capacity to metabolize fats. The limited nutritional response to the parenteral nutrition reflects more the presence of metabolic derangements which are characteristic of the cachexia syndrome (or merely the short duration of the nutritional support) rather than the inadequacy of the nutritional regimen. Perioperative parenteral nutrition is only recommended in malnourished patients if enteral nutrition is not feasible. In non-surgical well-nourished oncologic patients routine parenteral nutrition is not recommended because it has proved to offer no advantage and is associated with increased morbidity. A benefit, however, is reported in patients undergoing hematopoietic stem cell transplantation. Short-term parenteral nutrition is however commonly accepted in patients with acute gastrointestinal complications from chemotherapy and radiotherapy, and long-term (home) parenteral nutrition will sometimes be a life-saving maneuver in patients with sub acute/chronic radiation enteropathy. In incurable cancer patients home parenteral nutrition may be recommended in hypophagic/(sub)obstructed patients (if there is an acceptable performance status) if they are expected to die from starvation/under nutrition prior to tumor spread.

Plasma free amino acid profile in cancer patients

Redistribution or translocation of plasma free amino acids (PFAAs) to support visceral or tumor protein synthesis is an essential feature in cancer patients. An abnormal PFAA profile might be presented via the total reflection of cancer-induced protein metabolism in tumors, skeletal muscle and the liver in cancer patients. Clinical data from 13 studies have demonstrated a cancer-related PFAA profile, especially in digestive organ cancers. The PFAA profile can differ between the early and late stages of cancer. The profile is also affected by the type of cancer. Therefore, it is postulated that a detailed analysis of the PFAA profile may serve as one of the biological markers for cancer patients.

Nutritional support of the cancer patient: issues and dilemmas

Malnutrition in cancer patients results from multifactorial events and is associated with an alteration of quality of life and a reduced survival. A simple nutritional assessment program and early counselling by a dietitian are essential to guide nutritional support and to alert the physician to the need for enteral (EN) or parenteral nutrition (PN). A daily intake of 20-35 kcal/kg, with a balanced contribution of glucose and lipids, and of 0.2-0.35 g nitrogen/kg is recommended both for EN and PN, with an adequate provision of electrolytes, trace elements and vitamins. EN, always preferable for patients with an intact digestive tract, and PN are both safe and effective methods of administering nutrients. The general results in clinical practice suggest no tumor growth during nutritional support. The indiscriminate use of conventional EN and PN is not indicated in well-nourished cancer patients or in patients with mild malnutrition. EN or PN is not clinically efficacious for patients treated with chemotherapy or radiotherapy, unless there are prolonged periods of GI toxicity, as in the case of bone marrow transplant patients. Severely malnourished cancer patients undergoing major visceral surgery may benefit from perioperative nutritional support, preferably via enteral access. Nutritional support in palliative care should be based on the potential risks and benefits of EN and PN, and on the patient's and family's wishes. Research is currently directed toward the impact of nutritional pharmacology on the clinical outcome of cancer patients. Glutamine-supplemented PN is probably beneficial in bone marrow transplant patients. Immune diets are likely to reduce the rate of infectious complications and the length of hospital stay after GI surgery. Further studies are needed to determine the efficacy of such novel approaches in specific populations of cancer patients, and should also address the question of the overall cost-benefit ratio of nutritional pharmacology, and the effect of nutritional support on length and quality of life.

Grains or veins: is enteral nutrition really better than parenteral nutrition? A look at the evidence

BACKGROUND

Enteral nutrition is said to be better than parenteral nutrition for providing nutrition support to humans.

PURPOSE

To assess the literature documenting the assertions that enteral nutrition is superior to parenteral nutrition with respect to cost, safety, physiology, intestinal structure and function, bacterial translocation, and outcome.

DATA IDENTIFICATION

Sources included MEDLINE search, personal files, and references from human comparative studies of enteral vs parenteral nutrition.

STUDY SELECTION

The goal was to include all human studies directly addressing questions of comparative efficacy of enteral and parenteral nutrition. Emphasis was given to prospective randomized controlled studies where available. Retrospective comparisons were not included.

DATA EXTRACTION

An attempt was made to briefly summarize methodology and findings of relevant studies. No general attempt was made to assess quality of individual studies.

RESULTS OF DATA SYNTHESIS

Enteral nutrition appears to be less expensive than parenteral nutrition, but new economic analyses are needed given the newer aggressive access techniques for enteral nutrition. Enteral nutrition is associated with meaningful morbidity and mortality. The little comparative data existent suggest no differences in safety. Comparative studies of physiology and metabolism as well as comparative and noncomparative studies of intestinal function and structure do not support putative advantages of enteral nutrition. There is no evidence that enteral nutrition prevents bacterial translocation in humans. Enteral nutrition probably reduces septic morbidity compared with parenteral nutrition in abdominal trauma. Otherwise, there is no evidence that enteral nutrition consistently improves patient outcome compared with parenteral nutrition.

CONCLUSIONS

With the exception of decreased cost and probable reduced septic morbidity in acute abdominal trauma, the available literature does not support the thesis that enteral nutrition is better than parenteral nutrition in humans.

Efficacy of nutritional pharmacology in surgical patients

The present article reviews the current concepts of immune enhancement through nutritional support for the surgical patient as they are derived experimentally and clinically. Although the potential for altering outcome in surgical patients through nutritional enhancement exists, the authors caution against overzealous application of laboratory data in the clinical arena. Available clinical studies have, at best, only demonstrated modest benefits. It is appropriate that the current literature be critically reviewed to assess the efficacy of the agent(s) purported to be of clinical benefit. Although present reports of immune-enhancing nutrition regimens demonstrate no overwhelming benefits in the critically ill or immunocompromised patient, the pursuit of this science remains undaunted. Lessons learned from the past are leading to reinvestigations in the laboratory, as well as better designs of clinical trials that are free of distracting post-hoc analysis and performed clearly in an intention-to-treat manner.