Nutritional/metabolic response in older cancer patients

High-protein home parenteral nutrition in malnourished oncology patients: a systematic literature review

INTRODUCTION

Up to 83% of oncology patients are affected by cancer-related malnutrition, depending on tumour location and patient age. Parenteral nutrition can be used to manage malnutrition, but there is no clear consensus as to the optimal protein dosage. The objective of this systematic literature review (SLR) was to identify studies on malnourished oncology patients receiving home parenteral nutrition (HPN) where protein or amino acid delivery was reported in g/kg bodyweight/day, and to compare outcomes between patients receiving low (< 1 g/kg bodyweight/day), standard (1-1.5 g/kg/day), and high-protein doses (> 1.5 g/kg/day).

METHODS

Literature searches were performed on 5th October 2021 in Embase, MEDLINE, and five Cochrane Library and Centre for Reviews and Dissemination databases. Searches were complemented by hand-searching of conference proceedings, a clinical trial registry, and bibliographic reference lists of included studies and relevant SLRs/meta-analyses.

RESULTS

Nineteen publications were included; sixteen investigated standard protein, two reported low protein, and one included both, but none assessed high-protein doses. Only one randomised controlled trial (RCT) was identified; all other studies were observational studies. The only study to compare two protein doses reported significantly greater weight gain in patients receiving 1.15 g/kg/day than those receiving 0.77 g/kg/day.

CONCLUSION

At present, there is insufficient evidence to determine the optimal protein dosage for malnourished oncology patients receiving HPN. Data from non-HPN studies and critically ill patients indicate that high-protein interventions are associated with increased overall survival and quality of life; further studies are needed to establish whether the same applies in malnourished oncology patients.

Association of Systemic Inflammation and Overall Survival in Elderly Patients with Cancer Cachexia - Results from a Multicenter Study

Background

Systemic inflammation and cachexia are associated with adverse clinical outcomes in elderly patients with cancer. The survival outcomes of elderly patients with cancer cachexia (EPCC) with high inflammation and a high risk of mortality are unknown. This study aimed to investigate the impact of high inflammation on the prognosis of EPCC patients with high mortality.

Patients and Methods

This multicenter cohort study included 746 EPCC (age >65 years) with a mean age of 72.00 ± 5.24 years, of whom 489 (65.5%) were male. The cut-off value for the inflammation index was obtained using the optimal survival curve. The different inflammatory indicators were assessed using the concordance index (C-index), decision curve analysis (DCA), and prognostic receiver operating characteristic (ROC). The high mortality risk group of EPCC was defined by the 2011 Fearon Cancer Diagnostic Consensus. EPCC were divided into the high-risk group, which satisfies three diagnostic criteria, and a low-risk group, which satisfies only one or two diagnostic criteria.

Results

The C-index, DCA, and prognostic ROC indicated the superiority of advanced lung cancer inflammation index (ALI) compared with other indicators, including neutrophil–lymphocyte ratio (NLR), prognostic nutritional index (PNI), systemic immune-inflammation index (SII), and platelet–lymphocyte ratio (PLR). Whether ALI was used as a continuous or a categorical variable, ALI had a better prognostic value in EPCC compared with other inflammatory indicators. In particular, patients with low ALI (<25.03) had a worse overall survival (OS) than patients with high ALI (≥25.03) (P < 0.001, HR [95% CI] = 2.092 [1.590–2.751]). The combination effect analysis showed that the risk of mortality of the patients in the low-ALI and high-risk groups was 3.095-fold higher than that of patients in the high-ALI and low-risk groups.

Conclusion

The prognostic and discriminative value of the inflammatory indicator ALI was better than that of NLR, PNI, SII, and PLR in EPCC. The high-risk group of EPCC with a low ALI would increase the death risk of OS.

Understanding the Role of Exercise in Cancer Cachexia Therapy

Cachexia, the unintentional loss of body weight, is prevalent in many cancer types, and the associated skeletal muscle mass depletion increases patient morbidity and mortality. While anorexia can be present, cachexia is not reversible with nutritional therapies alone. Pharmacological agents have been proposed to treat this condition, but there are currently no approved treatments. Nonetheless, the hallmark characteristics associated with cancer cachexia remain viable foundations for future therapies. Regular physical activity holds a promising future as a nonpharmacological alternative to improve patient survival through cachexia prevention. Evidence suggests exercise training is beneficial during cancer treatment and survival. However, the mechanistic examination of cachectic skeletal muscle's response to exercise is both needed and justified. The primary objective of this review is to discuss the role of exercise for the prevention and treatment of cancer-associated muscle wasting. Initially, we provide an overview of systemic alterations induced by cancer and their role in the regulation of wasting processes during cachexia progression. We then discuss how exercise could alter disrupted regulatory pathways related to growth and metabolism during cancer-induced muscle atrophy. Last, we outline current exercise prescription guidelines and how exercise could be a potential behavioral therapy to curtail cachexia development in cancer patients.

Dysregulated Handling of Dietary Protein and Muscle Protein Synthesis After Mixed-Meal Ingestion in Maintenance Hemodialysis Patients

Introduction

Skeletal muscle loss is common in patients with renal failure who receive maintenance hemodialysis (MHD) therapy. Regular ingestion of protein-rich meals are recommended to help offset muscle protein loss in MHD patients, but little is known about the anabolic potential of this strategy.

Methods

Eight MHD patients (age: 56 ± 5 years; body mass index [BMI]: 32 ± 2 kg/m²) and 8 nonuremic control subjects (age: 50 ± 2 years: BMI: 31 ± 1 kg/m²) received primed continuous L-[ring-²H₅]phenylalanine and L-[1-¹³C]leucine infusions with blood and muscle biopsy sampling on a nondialysis day. Participants consumed a mixed meal (546 kcal; 20-g protein, 59-g carbohydrates, 26-g fat) with protein provided as L-[5,5,5-²H₃]leucine-labeled eggs.

Results

Circulating dietary amino acid availability was reduced in MHD patients (41 ± 5%) versus control subjects (61 ± 4%; P = 0.03). Basal muscle caspase-3 protein content was elevated (P = 0.03) and large neutral amino acid transporter 1 (LAT1) protein content was reduced (P = 0.02) in MHD patients versus control subjects. Basal muscle protein synthesis (MPS) was ∼2-fold higher in MHD patients (0.030 ± 0.005%/h) versus control subjects (0.014 ± 0.003%/h) (P = 0.01). Meal ingestion failed to increase MPS in MHD patients (absolute change from basal: 0.0003 ± 0.007%/h), but stimulated MPS in control subjects (0.009 ± 0.002%/h; P = 0.004).

Conclusions

MHD patients demonstrated muscle anabolic resistance to meal ingestion. This blunted postprandial MPS response in MHD patients might be related to high basal MPS, which results in a stimulatory ceiling effect and/or reduced plasma dietary amino acid availability after mixed-meal ingestion.

Forcing the vicious circle: sarcopenia increases toxicity, decreases response to chemotherapy and worsens with chemotherapy

Sarcopenia has recently emerged as a new condition that, independently from malnutrition, may adversely affect the prognosis of cancer patients. Purpose of this narrative review is to define the prevalence of sarcopenia in different primaries, its role in leading to chemotherapy toxicity and decreased compliance with the oncological therapy and the effect of some drugs on the onset of sarcopenia. Finally, the review aims to describe the current approaches to restore the muscle mass through nutrition, exercise and anti-inflammatory agents or multimodal programmes with a special emphasis on the results of randomized controlled trials. The examination of the computed tomography scan at the level of the third lumbar vertebra-a common procedure for staging many tumours-has allowed the oncologist to evaluate the muscle mass and to collect many retrospective data on the prevalence of sarcopenia and its clinical consequences. Sarcopenia is a condition affecting a high percentage of patients with a range depending on type of primary tumour and stage of disease. It is noteworthy that patients may be sarcopenic even if their nutritional status is apparently maintained or they are obese. Sarcopenic patients exhibited higher chemotherapy toxicity and poorer compliance with oncological treatments. Furthermore, several antineoplastic drugs appeared to worsen the sarcopenic status. Therapeutic approaches are several and this review will focus on those validated by randomized controlled trials. They include the use of ω-3-enriched oral nutritional supplements and orexigenic agents, the administration of adequate high-protein regimens delivered enterally or parenterally, and programmes of physical exercise. Better results are expected combining different procedures in a multimodal approach. In conclusion, there are several premises to prevent/treat sarcopenia. The oncologist should coordinate this multimodal approach by selecting priorities and sequences of treatments and then involving a nutrition health care professional or a physical therapist depending on the condition of the single patient.

Linking Cancer Cachexia-Induced Anabolic Resistance to Skeletal Muscle Oxidative Metabolism

Cancer cachexia, a wasting syndrome characterized by skeletal muscle depletion, contributes to increased patient morbidity and mortality. While the intricate balance between protein synthesis and breakdown regulates skeletal muscle mass, the suppression of basal protein synthesis may not account for the severe wasting induced by cancer. Therefore, recent research has shifted to the regulation of “anabolic resistance,” which is the impaired ability of nutrition and exercise to stimulate protein synthesis. Emerging evidence suggests that oxidative metabolism can regulate both basal and induced muscle protein synthesis. While disrupted protein turnover and oxidative metabolism in cachectic muscle have been examined independently, evidence suggests a linkage between these processes for the regulation of cancer-induced wasting. The primary objective of this review is to highlight the connection between dysfunctional oxidative metabolism and cancer-induced anabolic resistance in skeletal muscle. First, we review oxidative metabolism regulation of muscle protein synthesis. Second, we describe cancer-induced alterations in the response to an anabolic stimulus. Finally, we review a role for exercise to inhibit cancer-induced anabolic suppression and mitochondrial dysfunction.

An analysis of the types of recently published research in the field of cachexia

Introduction Cachexia is a common complication of many and varied chronic disease processes, yet it has received very little attention as an area of clinical research effort until recently. We sought to survey the contemporary literature on published research into cachexia to define where it is being published and the proportion of output classified into the main types of research output. Methods I searched the PubMed listings under the topic research term "cachexia" and related terms for articles published in the calendar years of 2015 and 2016, regardless of language. Searches were conducted and relevant papers extracted by two observers, and disagreements were resolved by consensus. Results There were 954 publications, 370 of which were review articles or commentaries, 254 clinical observations or non-randomised trials, 246 original basic science reports and only 26 were randomised controlled trials. These articles were published in 478 separate journals but with 36% of them being published in a core set of 23 journals. The H-index of these papers was 25 and there were 147 papers with 10 or more citations. Of the top 100 cited papers, 25% were published in five journals. Of the top cited papers, 48% were review articles, 18% were original basic science, and 7% were randomised clinical trials. Discussion This analysis shows a steady but modest increase in publications concerning cachexia with a strong pipeline of basic science research but still a relative lack of randomised clinical trials, with none exceeding 1000 patients. Research in cachexia is still in its infancy, but the solid basic science effort offers hope that translation into randomised controlled clinical trials may eventually lead to effective therapies for this troubling and complex clinical disease process.

Is Cancer Cachexia Attributed to Impairments in Basal or Postprandial Muscle Protein Metabolism?

Cachexia is a significant clinical problem associated with very poor quality of life, reduced treatment tolerance and outcomes, and a high mortality rate. Mechanistically, any sizeable loss of skeletal muscle mass must be underpinned by a structural imbalance between muscle protein synthesis and breakdown rates. Recent data indicate that the loss of muscle mass with aging is, at least partly, attributed to a blunted muscle protein synthetic response to protein feeding. Whether such anabolic resistance is also evident in conditions where cachexia is present remains to be addressed. Only few data are available on muscle protein synthesis and breakdown rates in vivo in cachectic cancer patients. When calculating the theoretical changes in basal or postprandial fractional muscle protein synthesis and breakdown rates that would be required to lose 5% of body weight within a six-month period, we can define the changes that would need to occur to explain the muscle mass loss observed in cachectic patients. If changes in both post-absorptive and postprandial muscle protein synthesis and breakdown rates contribute to the loss of muscle mass, it would take alterations as small as 1%–2% to induce a more than 5% decline in body weight. Therefore, when trying to define impairments in basal and/or postprandial muscle protein synthesis or breakdown rates using contemporary stable isotope methodology in cancer cachexia, we need to select large homogenous groups of cancer patients (>40 patients) to allow us to measure physiological and clinically relevant differences in muscle protein synthesis and/or breakdown rates. Insight into impairments in basal or postprandial muscle protein synthesis and breakdown rates in cancer cachexia is needed to design more targeted nutritional, pharmaceutical and/or physical activity interventions to preserve skeletal muscle mass and, as such, to reduce the risk of complications, improve quality of life, and lower mortality rates during the various stages of the disease.

Protein anabolic resistance in cancer: does it really exist?

PURPOSE OF REVIEW

Preventing unintentional weight and muscle loss is of crucial importance to maintain the condition and well-being of patients with cancer, improve treatment response and tolerance, and prolong survival. Anabolic resistance might explain why some cancer patients do not respond to nutritional intervention, but does recent evidence actually support this? We will discuss recent literature that casts doubt on attenuated anabolic potential in cancer.

RECENT FINDINGS

Although anabolic resistance was observed in the past, more recent studies have shown that advanced cancer patients have an anabolic potential after intake of high-quality proteins. Furthermore, a consistent linear relationship is observed in cancer between (essential) amino acid availability from the diet and net protein gain. The studied cancer patients, however, were often characterized by a normal or obese body weight, following the trend in the general population, and mild systemic inflammation. Factors like recent chemotherapy, surgery, or cachexia do not seem to attenuate the anabolic potential to feeding.

SUMMARY

Cancer patients have a normal anabolic potential which relates to the amount of essential amino acids in the meal. It remains to be determined if this is also the case in weak cancer patients with a short life expectancy and high systemic inflammation.