Fish oil mitigates myosteatosis and improves chemotherapy efficacy in a preclinical model of colon cancer

Body Composition in Cholangiocarcinoma Affects Immune Cell Populations in the Tumor and Normal Liver Parenchyma

Background

Due to malnutrition and tumor cachexia, body composition (BC) is frequently altered and known to adversely affect short- and long-term results in patients with cholangiocarcinoma (CCA). Here, we explored immune cell populations in the tumor and liver of CCA patients with respect to BC.

Methods

A cohort of 96 patients who underwent surgery for CCA was investigated by multiplexed immunofluorescence (MIF) techniques with computer-based analysis on whole-tissue slide scans to quantify and characterize immune cells in normal liver and tumor regions. BC was characterized by obesity, sarcopenia, myosteatosis, visceral obesity and sarcopenic obesity. Associations between BC and immune cell populations were determined by univariate and multivariable binary logistic regressions.

Results

BC was frequently altered in intrahepatic CCA (iCCA, n = 48), with 47.9% of the patients showing obesity, 70.8% sarcopenia, 18.8% sarcopenic obesity, 58.3% myosteatosis and 54.2% visceral obesity as well as in perihilar CCA (pCCA, n = 48) with 45.8% of the patients showing obesity, 54.0 sarcopenia, 14.6% sarcopenic obesity, 47.9% myosteatosis and 56.3% visceral obesity. From an immune cell perspective, independent associations within the tumor compartment were observed for iCCA (myosteatosis: TIM-3+CD8+cells; obesity: PD-1+TIM-3+CD4+cells) and for pCCA (myosteatosis: PD-L2+CD68-cells and CD4+cells). Further, independent associations were observed within the normal liver parenchyma for iCCA (visceral obesity: PD-1+PD-L1+PD-L2+CD68+cells) and for pCCA (sarcopenia: CD68+cells and TIM-3+CD8+cells; visceral obesity: ICOS+-TIGIT+CD8+cells and sarcopenic obesity: PD-1+PD-L1+PD-L2+CD8+cells).

Conclusion

This is the first systematic analysis of the association of BC and immune cells in cholangiocarcinoma showing a strong association between BC and distinct immune cell populations within the tumor itself as well as within the normal parenchyma.

Melanocortin-4 receptor antagonist TCMCB07 alleviates chemotherapy-induced anorexia and weight loss in rats

Cancer patients undergoing chemotherapy often experience anorexia and weight loss that substantially deteriorates overall health, reduces treatment tolerance and quality of life, and worsens oncologic outcomes. There are currently few effective therapeutic options to mitigate these side effects. The central melanocortin system, which plays a pivotal role in regulating appetite and energy homeostasis, presents a logical target for treating anorexia and weight loss. In this preclinical study, we evaluated the efficacy of TCMCB07, a synthetic antagonist of the melanocortin-4 receptor, in mitigating anorexia and weight loss in several rat models of chemotherapy: cisplatin, 5-fluorouracil, cyclophosphamide, vincristine, doxorubicin, and a combination of irinotecan and 5-fluorouracil. Our results indicate that peripheral administration of TCMCB07 improved appetite, stabilized body weight, preserved fat and heart mass, and slightly protected lean mass after multiple cycles of chemotherapy. Furthermore, combining TCMCB07 with a growth differentiation factor 15 antibody enhanced treatment effectiveness. Similar effects from TCMCB07 treatment were observed in a rat tumor model following combination chemotherapy. No notable adverse effects nor increased chemotherapy-related toxicities were observed with TCMCB07 treatment. These findings suggest that peripheral administration of TCMCB07 holds promise as a therapeutic approach for alleviating chemotherapy-induced anorexia and weight loss, potentially benefiting numerous patients undergoing chemotherapy.

Impact of Altered Body Composition on Clinical and Oncological Outcomes in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma is a common primary liver tumor with limited treatment options and poor prognosis. Changes in body composition (BC) have been shown to affect the prognosis of various types of tumors. Therefore, our study aimed to investigate the correlation between BC and clinical and oncological outcomes in patients with iCCA. All patients with iCCA who had surgery from 2010 to 2022 at our institution were included. We used CT scans and 3D Slicer software to assess BC and conducted logistic regressions as well as Cox regressions and Kaplan-Meier analyses to investigate associations between BC and clinical variables with focus on postoperative complications and oncological outcomes. BC was frequently altered in iCCA (n = 162), with 53.1% of the patients showing obesity, 63.2% sarcopenia, 52.8% myosteatosis, 10.1% visceral obesity, and 15.3% sarcopenic obesity. The multivariate analysis showed no meaningful association between BC and perioperative complications. Myosteatosis was associated with reduced overall survival (OS) in iCCA patients (myosteatosis vs. non-myosteatosis, 7 vs. 18 months, p = 0.016 log rank). Further, the subgroup analysis revealed a notable effect in the subset of R0-resected patients (myosteatosis vs. non-myosteatosis, 18 vs. 32 months, p = 0.025) and patients with nodal metastases (myosteatosis vs. non-myosteatosis, 7 vs. 18 months, p = 0.016). While altered BC is not associated with perioperative outcomes in iCCA, myosteatosis emerges as a prognostic factor for reduced OS in the overall and sub-populations of resected patients.

Increased Expression of Hepatic Stearoyl-CoA Desaturase (SCD)-1 and Depletion of Eicosapentaenoic Acid (EPA) Content following Cytotoxic Cancer Therapy Are Reversed by Dietary Fish Oil

Cancer treatment evokes impediments to liver metabolism that culminate in fatty liver. This study determined hepatic fatty acid composition and expression of genes and mediators involved in lipid metabolism following chemotherapy treatment. Female rats bearing the Ward colon tumor were administered Irinotecan (CPT-11) +5-fluorouracil (5-FU) and maintained on a control diet or a diet containing eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) (2.3 g/100 g fish oil). Healthy animals provided with a control diet served as a reference group. Livers were collected one week after chemotherapy. Triacylglycerol (TG), phospholipid (PL), ten lipid metabolism genes, leptin, and IL-4 were measured. Chemotherapy increased TG content and reduced EPA content in the liver. Expression of SCD1 was upregulated by chemotherapy, while dietary fish oil downregulated its expression. Dietary fish oil down-regulated expression of the fatty acid synthesis gene FASN, while restoring the long chain fatty acid converting genes FADS2 and ELOVL2, and genes involved in mitochondrial β-oxidation (CPT1α) and lipid transport (MTTP1), to values similar to reference animals. Neither leptin nor IL-4 were affected by chemotherapy or diet. Depletion of EPA is associated with pathways evoking enhanced TG accumulation in the liver. Restoring EPA through diet may pose a dietary strategy to attenuate chemotherapy-associated impediments in liver fatty acid metabolism.

Dietary EPA+DHA Mitigate Hepatic Toxicity and Modify the Oxylipin Profile in an Animal Model of Colorectal Cancer Treated with Chemotherapy

Irinotecan (CPT-11) and 5-fluorouracil (5-FU) are commonly used to treat metastatic colorectal cancer, but chemotherapy-associated steatosis/steatohepatitis (CASSH) frequently accompanies their use. The objective of this study was to determine effect of CPT-11+5-FU on liver toxicity, liver oxylipins, and cytokines, and to explore whether these alterations could be modified by dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the form of fish oil (EPA+DHA). Tumor-bearing animals were administered CPT-11+5-FU and maintained on a control diet or a diet containing EPA+DHA (2.3 g/100 g). Livers were collected one week after chemotherapy for the analysis of oxylipins, cytokines, and markers of liver pathology (oxidized glutathione, GSSH; 4-hydroxynonenal, 4-HNE, and type-I collagen fiber). Dietary EPA+DHA prevented the chemotherapy-induced increases in liver GSSH (p < 0.011) and 4-HNE (p < 0.006). Compared with the tumor-bearing animals, ten oxylipins were altered (three/ten n-6 oxylipins were elevated while seven/ten n-3 oxylipins were reduced) following chemotherapy. Reductions in the n-3 fatty-acid-derived oxylipins that were evident following chemotherapy were restored by dietary EPA+DHA. Liver TNF-α, IL-6 and IL-10 were elevated (p < 0.05) following chemotherapy; dietary EPA+DHA reduced IL-6 (p = 0.09) and eotaxin (p = 0.007) levels. Chemotherapy-induced liver injury results in distinct alterations in oxylipins and cytokines, and dietary EPA+DHA attenuates these pathophysiological effects.

A Review of free fatty acid-induced cell signaling, angiopoietin-like protein 4, and skeletal muscle differentiation

Postnatal skeletal muscle differentiation from quiescent satellite cells is a highly regulated process, although our understanding of the contribution of nutritional factors in myogenesis is limited. Free fatty acids (FFAs) are known to cause detrimental effects to differentiated skeletal muscle cells by increasing oxidative stress which leads to muscle wasting and insulin resistance in skeletal muscle. In addition, FFAs are thought to act as inhibitors of skeletal muscle differentiation. However, the precise molecular mechanisms underlying the effects of FFAs on skeletal muscle differentiation remains to be elucidated. There is a clear relationship between dietary FFAs and their ability to suppress myogenesis and we propose the hypothesis that the FFA-mediated increase in angiopoietin-like protein 4 (ANGPTL4) may play a role in the inhibition of differentiation. This review discusses the role of FFAs in skeletal muscle differentiation to-date and proposes potential mechanisms of FFA-induced ANGPTL4 mediated inhibition of skeletal muscle differentiation.

Myosteatosis in Cirrhosis: A Review of Diagnosis, Pathophysiological Mechanisms and Potential Interventions

Myosteatosis, or pathological excess fat accumulation in muscle, has been widely defined as a lower mean skeletal muscle radiodensity on computed tomography (CT). It is reported in more than half of patients with cirrhosis, and preliminary studies have shown a possible association with reduced survival and increased risk of portal hypertension complications. Despite the clinical implications in cirrhosis, a standardized definition for myosteatosis has not yet been established. Currently, little data exist on the mechanisms by which excess lipid accumulates within the muscle in individuals with cirrhosis. Hyperammonemia may play an important role in the pathophysiology of myosteatosis in this setting. Insulin resistance, impaired mitochondrial oxidative phosphorylation, diminished lipid oxidation in muscle and age-related differentiation of muscle stem cells into adipocytes have been also been suggested as potential mechanisms contributing to myosteatosis. The metabolic consequence of ammonia-lowering treatments and omega-3 polyunsaturated fatty acids in reversing myosteatosis in cirrhosis remains uncertain. Factors including the population of interest, design and sample size, single/combined treatment, dosing and duration of treatment are important considerations for future trials aiming to prevent or treat myosteatosis in individuals with cirrhosis.

Skeletal muscle radiodensity and cancer outcomes: A scoping review of the literature

Patients with cancer are more prone to experience myosteatosis than healthy individuals. The aim of this review was to summarize the methodologies applied for low skeletal muscle radiodensity (SMD) assessment in oncology patients, as well as to describe the major findings related to SMD and cancer outcomes. This scoping review included studies that were published until November 2020 in English, Portuguese, or Spanish; were performed in humans diagnosed with cancer, adult and/or elderly, of both sexes; investigated SMD through computed tomography of the region between the third and fifth lumbar vertebrae, considering at least two muscular groups; and evaluated clinical and/or surgical outcomes. Eighty-eight studies met the inclusion criteria (n = 37,583 patients). Survival was the most evaluated outcome. Most studies reported a significant association between low SMD and unfavorable outcomes. However, this relationship was not clear for survival, antineoplastic treatment, and surgical complications, potentially because of the unstandardized approaches for the assessment of SMD and inadequate study design. Future studies should address these issues to provide an in-depth understanding of the clinical relevance of SMD in cancer outcomes as well as how SMD is influenced by individuals and tumor-related characteristics in patients with cancer.

Microbiota-Host-Irinotecan Axis: A New Insight Toward Irinotecan Chemotherapy

Irinotecan (CPT11) and its active metabolite ethyl-10-hydroxy-camptothecin (SN38) are broad-spectrum cytotoxic anticancer agents. Both cause cell death in rapidly dividing cells (e.g., cancer cells, epithelial cells, hematopoietic cells) and commensal bacteria. Therefore, CPT11 can induce a series of toxic side-effects, of which the most conspicuous is gastrointestinal toxicity (nausea, vomiting, diarrhea). Studies have shown that the gut microbiota modulates the host response to chemotherapeutic drugs. Targeting the gut microbiota influences the efficacy and toxicity of CPT11 chemotherapy through three key mechanisms: microbial ecocline, catalysis of microbial enzymes, and immunoregulation. This review summarizes and explores how the gut microbiota participates in CPT11 metabolism and mediates host immune dynamics to affect the toxicity and efficacy of CPT11 chemotherapy, thus introducing a new concept that is called "microbiota-host-irinotecan axis". Also, we emphasize the utilization of bacterial β-glucuronidase-specific inhibitor, dietary interventions, probiotics and strain-engineered interventions as emergent microbiota-targeting strategies for the purpose of improving CPT11 chemotherapy efficiency and alleviating toxicity.

Alterations in hepatic fatty acids reveal depletion of total polyunsaturated fatty acids following irinotecan plus 5-fluorouracil treatment in an animal model of colorectal cancer

Fatty liver is a side effect of chemotherapy that limits the ability to treat colorectal cancer (CRC) patients in the most effective way. The aim of this study was to determine hepatic fatty acid composition and expression of genes involved in lipid metabolism at two time points following sequential chemotherapy treatment with Irinotecan (CPT-11)+5-fluorouracil (5-FU), agents commonly used to treat human colorectal cancer. Female Fischer 344 rats were provided a semi-purified AIN-76 basal diet with modified fat component. One cycle of chemotherapy consisted of CPT-11+5-FU and was initiated 2 weeks after tumor implantation (D0); a second cycle was given one week later. Two days after each cycle (Day 2 and Day 9), animals were euthanized, and livers collected. Triacylglycerol (TAG) and phospholipid (PL) fractions were isolated using thin layer chromatography and fatty acids (FAs) were quantified using gas chromatography. Expression of 44 lipid metabolism genes were analyzed by qPCR. Total liver TAG level was lowest after the second cycle D0 and D2 (P = 0.05) characterized by lower content of n-6 and n-3 polyunsaturated fatty acids (PUFAs). N-6 PUFAs significantly declined with subsequent treatments. Of 44 genes analyzed, 13 genes were altered with CPT-11+5-FU treatment. Expression of genes VLCAD and DGAT1, involved in fatty acid oxidation as well as DGAT1 in TAG synthesis, were significantly elevated after each cycle, whereas expression of genes ELOVL2 and FADS2, involved in fatty acid elongation and desaturation were significantly lower at D9 compared to D2 and D0 (P < 0.03). Hepatic total TAG PUFA was depleted, and genes involved in pathways of PUFA synthesis were down-regulated by chemotherapy treatment. This observation suggests impediments in lipid metabolism in the liver that could potentially impact peripheral availability of essential fatty acids.

A Retrospective Cohort Study of Myosteatosis and Quality of Life in Head and Neck Cancer Patients

Simple Summary

Quality of life (QOL) is an important patient reported outcome that effects both care and life outside of treatment. There is a shortage of nontaxing ways to determine which patients may need enhanced care over the course of their therapy and beyond to help avoid long-term declines in QOL. Therefore, we investigated whether myosteatosis as determined through existing diagnostic imaging could be used to predict QOL trajectories. In this study, patients with pretreatment myosteatosis were more likely to have lower physical and global QOL scores than patients with normal muscle density. In conclusion, myosteatosis may be a way of determining patients in need of extra assistance over the course of treatment and afterwards.

Abstract

Head and neck cancer (HNC) treatment-related morbidity can be detrimental to quality of life (QOL). Myosteatosis is associated with poor QOL in multiple cancers. If predictive of poor QOL trajectories, myosteatosis would be a tool for clinicians to determine which patients may require additional support during treatment. The purpose of this study was to determine if pretreatment myosteatosis is associated with a poor QOL trajectory following treatment completion. Methods: In a retrospective cohort design, myosteatosis was determined from pretreatment CT scans. Both physical and global QOL score was assessed through patient interview on follow-up appointment. Demographic, cancer-specific, and social covariates were collected, reported, and considered as potential confounders. Results: The population of 163 patients was mostly male (82.2%) and white (91.4%) with oropharyngeal cancer (55.8%). Males with myosteatosis had a physical QOL score 46.84 points lower at one-year following treatment completion (p = 0.01) than those with normal muscle density (p = 0.01). Males with myosteatosis averaged 57.57 points lower at one-year post-treatment (p = 0.01) in global QOL scores. Conclusions: Over one year following completion of treatment, patients with myosteatosis reported worse physical and global QOL scores than patients with normal muscle density.

Metabolic Remodeling in Skeletal Muscle Atrophy as a Therapeutic Target

Skeletal muscle is a highly responsive tissue, able to remodel its size and metabolism in response to external demand. Muscle fibers can vary from fast glycolytic to slow oxidative, and their frequency in a specific muscle is tightly regulated by fiber maturation, innervation, or external causes. Atrophic conditions, including aging, amyotrophic lateral sclerosis, and cancer-induced cachexia, differ in the causative factors and molecular signaling leading to muscle wasting; nevertheless, all of these conditions are characterized by metabolic remodeling, which contributes to the pathological progression of muscle atrophy. Here, we discuss how changes in muscle metabolism can be used as a therapeutic target and review the evidence in support of nutritional interventions and/or physical exercise as tools for counteracting muscle wasting in atrophic conditions.

Chemotherapy-Induced Myopathy: The Dark Side of the Cachexia Sphere

Simple Summary

In addition to cancer-related factors, anti-cancer chemotherapy treatment can drive life-threatening body wasting in a syndrome known as cachexia. Emerging evidence has described the impact of several key chemotherapeutic agents on skeletal muscle in particular, and the mechanisms are gradually being unravelled. Despite this evidence, there remains very little research regarding therapeutic strategies to protect muscle during anti-cancer treatment and current global grand challenges focused on deciphering the cachexia conundrum fail to consider this aspect—chemotherapy-induced myopathy remains very much on the dark side of the cachexia sphere. This review explores the impact and mechanisms of, and current investigative strategies to protect against, chemotherapy-induced myopathy to illuminate this serious issue.

Abstract

Cancer cachexia is a debilitating multi-factorial wasting syndrome characterised by severe skeletal muscle wasting and dysfunction (i.e., myopathy). In the oncology setting, cachexia arises from synergistic insults from both cancer–host interactions and chemotherapy-related toxicity. The majority of studies have surrounded the cancer–host interaction side of cancer cachexia, often overlooking the capability of chemotherapy to induce cachectic myopathy. Accumulating evidence in experimental models of cachexia suggests that some chemotherapeutic agents rapidly induce cachectic myopathy, although the underlying mechanisms responsible vary between agents. Importantly, we highlight the capacity of specific chemotherapeutic agents to induce cachectic myopathy, as not all chemotherapies have been evaluated for cachexia-inducing properties—alone or in clinically compatible regimens. Furthermore, we discuss the experimental evidence surrounding therapeutic strategies that have been evaluated in chemotherapy-induced cachexia models, with particular focus on exercise interventions and adjuvant therapeutic candidates targeted at the mitochondria.

Dietary citrulline does not modify rat colon tumor response to chemotherapy, but failed to improve nutritional status

During cancer therapy many patients experience significant malnutrition, leading to decreased tolerance to chemotherapy and decreased survival. Dietary citrulline supplementation improves nutritional status in situations such as short bowel syndrome and aging, and is of potential interest in oncology. However, a mandatory prerequisite is to test this amino acid for interaction with tumor growth and chemotherapy response. Dietary citrulline (Cit; 2%), or an isonitrogenous mix of non-essential amino acids (control), was given to Ward colon tumor-bearing rats the day before chemotherapy initiation. Chemotherapy included 2 cycles, one week apart, each consisting of one injection of CPT-11 (50 mg/kg) and of 5-fluorouracil (50 mg/kg) the day after. Body weight, food intake and tumor volume were measured daily. The day after the last injection, rats were killed, muscles (EDL, gastrocnemius), intestinal mucosa, tumor, spleen and liver were weighed. Muscle and intestinal mucosa protein content were measured. Phosphorylated 4E-BP1 was measured in muscle and tumor as a surrogate for biosynthetic activation. FRAPS (Ferric Reducing Ability of Plasma) and thiols in plasma, muscle and tumor were evaluated and plasma amino acids and haptoglobin were measured. Numerous parameters did not differ by diet overall: a) response of tumor mass to treatment, b) tumor antioxidants and phosphorylated 4E-BP1 levels, c) relative body weight and relative food intake, d) weight of EDL, gastrocnemius, intestinal mucosa, spleen and liver and e) plasma haptoglobin concentrations. Moreover, plasma citrulline concentration was not correlated to relative body weight, only cumulated food intake and plasma haptoglobin concentrations were correlated to relative body weight. Citrulline does not alter the tumor response to CPT-11/5FU based therapy but, has no effect on nutritional status, which could be due to the anorexia and the low amount of citrulline and protein ingested.

Cancer cachexia and skeletal muscle atrophy in clinical studies: what do we really know?

Research investigators have shown a growing interest in investigating alterations underlying skeletal muscle wasting in patients with cancer. However, skeletal muscle dysfunctions associated with cancer cachexia have mainly been studied in preclinical models. In the present review, we summarize the results of clinical studies in which skeletal muscle biopsies were collected from cachectic vs. non-cachectic cancer patients. Most of these studies suggest the presence of significant physiological alterations in skeletal muscle from cachectic cancer patients. We suggest a hypothesis, which connects structural and metabolic parameters that may, at least in part, be responsible for the skeletal muscle atrophy characteristic of cancer cachexia. Finally, we discuss the importance of a better standardization of the diagnostic criteria for cancer cachexia, as well as the requirement for additional clinical studies to improve the robustness of these conclusions.

Body composition as reflected by intramuscular adipose tissue content may influence short- and long-term outcome following 2-stage liver resection for colorectal liver metastases

INTRODUCTION

For many kinds of cancer, body composition and immunonutritional status have been reported to influence postoperative outcome. We assessed their impact on short- and long-term outcome in patients with colorectal liver metastases who underwent 2-stage liver resections.

METHODS

Short- and long-term outcomes for 47 patients with 2-stage hepatectomies were assessed retrospectively in terms of data obtained before preoperative chemotherapy, before the first hepatectomy, and before the second hepatectomy.

RESULTS

Although immunonutritional status and body composition did not affect short-term outcome, high intramuscular fat content before the second hepatectomy was a poor prognostic factor for overall survival (HR, 5.829; 95% CI, 1.611-21.090; p = 0.007) and for recurrence-free survival (HR, 2.787; 95% CI, 1.301-5.973; p = 0.008). Patients with high intramuscular fat before the second hepatectomy also showed shorter intervals from recurrence to treatment failure.

CONCLUSION

Intramuscular fat before the second hepatectomy is an important negative prognosticator in 2-stage liver resection for colorectal liver metastases.

Review article: prognostic significance of body composition abnormalities in patients with cirrhosis

BACKGROUND

Recent advances in evaluation of body composition show body mass index to be inadequate in differentiating between body compartments in cirrhosis. Given the limitations of body mass index, body composition evaluation using computed tomography has been increasingly used as a non-invasive clinical tool with prognostic value. Another factor influencing prognosis includes sex-specific differences in body composition that are seen in cirrhosis.

AIM

To review current knowledge regarding the frequency and clinical implications of abnormal body composition features in cirrhosis.

METHODS

We searched PubMed database and limited the literature search to full-text papers published in English. Studies using inappropriate landmarks or demarcation of body composition components on computed tomography images were eliminated.

RESULTS

Sarcopenia is a well established factor affecting morbidity and mortality in cirrhosis. Other important body composition components that have been overlooked thus far include subcutaneous adipose tissue and visceral adipose tissue. Female patients with cirrhosis and low subcutaneous adiposity have a higher risk of mortality, whereas male patients with high visceral adiposity have a higher risk of hepatocellular carcinoma and recurrence following liver transplantation. Increased adipose tissue radiodensity has been associated with risk of decompensation and mortality.

CONCLUSIONS

Further evaluation of body composition abnormalities may help with development of targeted therapeutic strategies and improve outcome in patients with cirrhosis. Moreover, recognition of these abnormalities could improve prioritisation for liver transplantation as our current method based solely on liver function might lead to risk misclassification.

Assessing skeletal muscle radiodensity by computed tomography: An integrative review of the applied methodologies

Low-radiodensity skeletal muscle has been related to the degree of muscle fat infiltration and seems to be associated with worse outcomes. The aim of this study was to summarize the methodologies used to appraise skeletal muscle radiodensity by computed tomography, to describe the terms used in the literature to define muscle radiodensity and to give recommendations for its measurement standardization. An integrative bibliographic review in four databases included studies published until August 2019 in Portuguese, English or Spanish and performed in humans, adults and/or the elderly, of both sex, which investigated skeletal muscle radiodensity through computed tomography (CT) of the region between the third and fifth lumbar vertebrae and evaluated at least two muscular groups. One hundred and seventeen studies were selected. We observed a trend towards selecting all abdominal region muscle. A significant methodological variation in terms of contrast use, selection of skeletal muscle areas, radiodensity ranges delimitation and their cut-off points, as well as the terminologies used, was also found. The methodological differences detected are probably due to the lack of more precise information about the correlation between skeletal muscle radiodensity by CT and its molecular composition, among others. Therefore, until the gaps are addressed in future studies, authors should avoid arbitrary approaches when reporting skeletal muscle radiodensity, especially when it comes to prognosis inference. Studies using both CT and direct methods of muscle composition evaluation are encouraged, to enable the definition and validation of the best approach to classify fat-infiltrated muscle tissue, which will favour the nomenclature uniformization.

Chemotherapy-Induced Sarcopenia

OPINION STATEMENT

Sarcopenia is being consistently recognized as a condition not only associated with the presence of a malignancy but also induced by the oncologic therapies. Due to its negative impact on tolerance to chemotherapy and final outcome in both medical and surgical cancer patients, sarcopenia should be always considered and prevented, and, if recognized, should be appropriately treated. A CT scan at the level of the third lumbar vertebra, using an appropriate software, is the more common and easily available way to diagnose sarcopenia. It is now acknowledged that mechanisms involved in iatrogenic sarcopenia are several and depending on the type of molecule included in the regimen of chemotherapy, different pharmacologic antidotes will be required in the future. However, progression of the disease and the associated malnutrition per se are able to progressively erode the muscle mass and since sarcopenia is the hallmark of cachexia, the therapeutic approach to chemotherapy-induced sarcopenia parallels that of cachexia. This approach mainly relies on those strategies which are able to increase the lean body mass and include the use of anabolic/anti-inflammatory agents, nutritional interventions, physical exercise and, even better, a combination of different therapies. There are some phase II studies and some small controlled randomized trials which have validated these treatments using single agents or combined multimodal approaches. While these approaches may require the cooperation of some specialists (nutritionists with a specific knowledge on pathophysiology of catabolic states, accredited exercise physiologists and physiotherapists), the oncologist too should directly enter these issues to coordinate the choice and priority of the treatments. Who better than the oncologist knows the natural history of the disease, its evolution, and the probability of tolerance and response to the oncologic therapy? Only the oncologist knows when it is essential to potentiate any effort to better achieve a control of the disease, using all the available armamentarium, and when the condition is too advanced and hence requires a more palliative than supporting care. The oncologist also knows when to expect a gastrointestinal toxicity (mucositis, nausea, vomiting, and diarrhea) and hence it is more convenient using a parenteral than an enteral nutritional intervention or, on the contrary, when patient is suitable for discharge from hospital and oral supplements should be promptly tested for compliance and then prescribed. When patients are at high risk for malnutrition or if, regardless of their nutritional status, they are candidate to aggressive and potentially toxic treatments, they should undergo a jointed evaluation by the oncologist and the nutritionist and physical therapist to assess together a combined approach. In conclusion, the treatment of both cancer- or chemotherapy-related sarcopenia represents a challenge for the modern oncologist who must be able to coordinate a new panel of specialists with the same skill necessary to decide the priority of different oncologic treatments within a complex multidisciplinary context.

A window beneath the skin: how computed tomography assessment of body composition can assist in the identification of hidden wasting conditions in oncology that profoundly impact outcomes

Advancements in image-based technologies and body composition research over the past decade has led to increased understanding of the importance of muscle abnormalities, such as low muscle mass (sarcopenia), and more recently low muscle attenuation (MA), as important prognostic indicators of unfavourable outcomes in patients with cancer. Muscle abnormalities can be highly prevalent in patients with cancer (ranging between 10 and 90 %), depending on the cohort under investigation and diagnostic criteria used. Importantly, both low muscle mass and low MA have been associated with poorer tolerance to chemotherapy, increased risk of post-operative infectious and non-infectious complications, increased length of hospital stay and poorer survival in patients with cancer. Studies have shown that systemic antineoplastic treatment can exacerbate losses in muscle mass and MA, with reported loss of skeletal muscle between 3 and 5 % per 100 d, which are increased exponentially with progressive disease and proximity to death. At present, no effective medical intervention to improve muscle mass and MA exists. Most research to date has focused on treating muscle depletion as part of the cachexia syndrome using nutritional, exercise and pharmacological interventions; however, these single-agent therapies have not provided promising results. Rehabilitation care to modify body composition, either increasing muscle mass and/or MA should be conducted, and its respective impact on oncology outcomes explored. Although the optimal timing and treatment strategy for preventing or delaying the development of muscle abnormalities are yet to be determined, multimodal interventions initiated early in the disease trajectory appear to hold the most promise.