Clinical and biological characterization of skeletal muscle tissue biopsies of surgical cancer patients.

BACKGROUND: Researchers increasingly use intraoperative muscle biopsy to investigate mechanisms of skeletal muscle atrophy in patients with cancer. Muscles have been assessed for morphological, cellular, and biochemical features. The aim of this study was to conduct a state-of-the-science review of this literature and, secondly, to evaluate clinical and biological variation in biopsies of rectus abdominis (RA) muscle from a cohort of patients with malignancies. METHODS: Literature was searched for reports on muscle biopsies from patients with a cancer diagnosis. Quality of reports and risk of bias were assessed. Data abstracted included patient characteristics and diagnoses, sample size, tissue collection and biobanking procedures, and results. A cohort of cancer patients (n = 190, 88% gastrointestinal malignancies), who underwent open abdominal surgery as part of their clinical care, consented to RA biopsy from the site of incision. Computed tomography (CT) scans were used to quantify total abdominal muscle and RA cross-sectional areas and radiodensity. Biopsies were assessed for muscle fibre area (µm2 ), fibre types, myosin heavy chain isoforms, and expression of genes selected for their involvement in catabolic pathways of muscle. RESULTS: Muscle biopsy occurred in 59 studies (total N = 1585 participants). RA was biopsied intraoperatively in 40 studies (67%), followed by quadriceps (26%; percutaneous biopsy) and other muscles (7%). Cancer site and stage, % of male participants, and age were highly variable between studies. Details regarding patient medical history and biopsy procedures were frequently absent. Lack of description of the population(s) sampled and low sample size contributed to low quality and risk of bias. Weight-losing cases were compared with weight stable cancer or healthy controls without considering a measure of muscle mass in 21 out of 44 studies. In the cohort of patients providing biopsy for this study, 78% of patients had preoperative CT scans and a high proportion (64%) met published criteria for sarcopenia. Fibre type distribution in RA was type I (46% ± 13), hybrid type I/IIA (1% ± 1), type IIA (36% ± 10), hybrid type IIA/D (15% ± 14), and type IID (2% ± 5). Sexual dimorphism was prominent in RA CT cross-sectional area, mean fibre cross-sectional area, and in expression of genes associated with muscle growth, apoptosis, and inflammation (P < 0.05). Medical history revealed multiple co-morbid conditions and medications. CONCLUSIONS: Continued collaboration between researchers and cancer surgeons enables a more complete understanding of mechanisms of cancer-associated muscle atrophy. Standardization of biobanking practices, tissue manipulation, patient characterization, and classification will enhance the consistency, reliability, and comparability of future studies.

Sarcopenic obesity and myosteatosis are associated with higher mortality in patients with cirrhosis.

BACKGROUND AND AIMS: Obesity is frequently associated with cirrhosis, and cirrhotic patients may develop simultaneous loss of skeletal muscle and gain of adipose tissue, culminating in the condition of sarcopenic obesity. Additionally, muscle depletion is characterized by both a reduction in muscle size and increased proportion of muscular fat, termed myosteatosis. In this study, we aimed to establish the frequency and clinical significance of sarcopenia, sarcopenic obesity and myosteatosis in cirrhotic patients. METHODS: We analysed 678 patients with cirrhosis. Sarcopenia, sarcopenic obesity and myosteatosis were analysed by CT scan using the third lumbar vertebrae skeletal muscle and attenuation indexes, using previously validated gender-and body mass index-specific cutoffs. RESULTS: Patients were predominately men (n = 457, 67%), and cirrhosis aetiology was hepatitis C virus in 269 patients (40%), alcohol in 153 (23%), non-alcoholic steatohepatitis/cryptogenic in 96 (14%), autoimmune liver disease in 55 (8%), hepatitis B virus in 43 (6%), and others in 5 patients (1%). Sarcopenia was present in 292 (43%), 135 had sarcopenic obesity (20%) and 353 had myosteatosis (52%). Patients with sarcopenia (22 ± 3 vs. 95 ± 22 months, P < 0.001), sarcopenic obesity (22 ± 3 vs. 95 ± 22 months, P < 0.001), and myosteatosis (28 ± 5 vs. 95 ± 22 months, P < 0.001) had worse median survival than patients without muscular abnormalities. By multivariate Cox regression analysis, both sarcopenia [hazard ratio (HR) 2.00, 95% confidence interval (CI) 1.44-2.77, P < 0.001], and myosteatosis (HR 1.42, 95% CI 1.02-1.07, P = 0.04) were associated with mortality. CONCLUSIONS: Sarcopenia, sarcopenic obesity and myosteatosis are often present in patients with cirrhosis, and sarcopenia and myosteatosis are independently associated with a higher long-term mortality in cirrhosis.

Body Composition Assessment in Axial CT Images Using FEM-Based Automatic Segmentation of Skeletal Muscle.

The proportions of muscle and fat tissues in the human body, referred to as body composition is a vital measurement for cancer patients. Body composition has been recently linked to patient survival and the onset/recurrence of several types of cancers in numerous cancer research studies. This paper introduces a fully automatic framework for the segmentation of muscle and fat tissues from CT images to estimate body composition. We developed a novel finite element method (FEM) deformable model that incorporates a priori shape information via a statistical deformation model (SDM) within the template-based segmentation framework. The proposed method was validated on 1000 abdominal and 530 thoracic CT images and we obtained very good segmentation results with Jaccard scores in excess of 90% for both the muscle and fat regions.

Inclusion of Sarcopenia Within MELD (MELD-Sarcopenia) and the Prediction of Mortality in Patients With Cirrhosis.

OBJECTIVES: Limitations of the Model for End-Stage Liver Disease (MELD) score include its failure to assess the nutritional and functional status of cirrhotic patients. Our objectives were to evaluate the impact of sarcopenia in cirrhosis and whether the inclusion of muscularity assessment within MELD could improve the prediction of mortality in patients with cirrhosis. METHODS: We included 669 cirrhotic patients who were consecutively evaluated for liver transplantation. Skeletal muscle index at the third lumbar vertebra (L3 SMI) was measured by computed tomography, and sarcopenia was defined using previously published gender and body mass index-specific cutoffs. Using Cox proportional hazards regression, a novel MELD-sarcopenia score was derived. RESULTS: Sarcopenia was present in 298 patients (45%); sarcopenic patients had shorter median survival than non-sarcopenic patients (20±3 vs. 95±24 months, P<0.001). By Cox regression analysis adjusted for age, gender, and hepatocellular carcinoma, both MELD (hazard ratio (HR) 1.08, 95% confidence interval (CI) 1.06-1.10, P<0.001), and the L3 SMI (HR 0.97, 95% CI 0.96-0.99, P<0.001) were associated with mortality. Overall, the c-statistics for 3-month mortality were 0.82 (95% CI 0.78-0.87) for MELD and 0.85 (95% CI 0.81-0.88) for MELD-sarcopenia (P=0.1). Corresponding figures for 1-year mortality were 0.73 (95% CI 0.69-0.77) and 0.77 (95% CI 0.73-0.80), respectively (P=0.03). The c-statistics for 3-month mortality in patients with MELD<15 (0.85 vs. 0.69, P=0.02) and refractory ascites (0.74 vs. 0.71, P=0.01) were significantly higher for MELD-sarcopenia compared with MELD. CONCLUSIONS: Modification of MELD to include sarcopenia is associated with improved prediction of mortality in patients with cirrhosis, primarily in patients with low MELD scores. External validation of this prognostic index in larger cohorts of cirrhotic patients is warranted.

Severe muscle depletion predicts postoperative length of stay but is not associated with survival after liver transplantation.

Muscle depletion or sarcopenia is associated with increased mortality in patients with cirrhosis; how it affects mortality after liver transplantation requires further study. In this study, we aimed to establish whether sarcopenia predicts increased morbidity or mortality after liver transplantation. We analyzed 248 patients with cirrhosis who had a computed tomography (CT) scan including the third lumbar vertebra before liver transplantation. Data were recovered from medical charts, the skeletal muscle cross-sectional area was measured with CT, and sarcopenia was defined with previously published sex- and body mass index-specific cutoffs. One hundred sixty-nine patients (68%) were male, and the mean age at transplantation was 55 ± 1 years. The etiologies of cirrhosis were hepatitis C virus (51%), alcohol (19%), autoimmune liver diseases (15%), hepatitis B virus (8%), and other etiologies (7%). Sarcopenia was present in 112 patients (45%), and it was more frequent in males (P = 0.002), patients with ascites (P = 0.02), and patients with higher bilirubin levels (P = 0.05), creatinine levels (P = 0.02), international normalized ratios (P = 0.04), Child-Pugh scores (P = 0.002), and Model for End-Stage Liver Disease scores (P = 0.002). The median survival period after liver transplantation was 117 ± 17 months for sarcopenic patients and 146 ± 20 months for nonsarcopenic patients (P = 0.4). Sarcopenic patients had longer hospital stays (40 ± 4 versus 25 ± 3 days; P = 0.005) and a higher frequency of bacterial infections within the first 90 days after liver transplantation (26% versus 15%, P = 0.04) in comparison with nonsarcopenic patients. In conclusion, sarcopenia is one of the most common complications in patients with cirrhosis and is predictive of longer hospital stays and a higher risk of perioperative bacterial infections after liver transplantation, but it is not associated with increased mortality.

Central tenet of cancer cachexia therapy: do patients with advanced cancer have exploitable anabolic potential?

BACKGROUND: Skeletal muscle wasting is considered the central feature of cachexia, but the potential for skeletal muscle anabolism in patients with advanced cancer is unproven. OBJECTIVE: We investigated the clinical course of skeletal muscle wasting in advanced cancer and the window of possible muscle anabolism. DESIGN: We conducted a quantitative analysis of computed tomography (CT) images for the loss and gain of muscle in population-based cohorts of advanced cancer patients (lung, colorectal, and pancreas cancer and cholangiocarcinoma) in a longitudinal observational study. RESULTS: Advanced-cancer patients (n = 368; median survival: 196 d) had a total of 1279 CT images over the course of their disease. With consideration of all time points, muscle loss occurred in 39% of intervals between any 2 scans. However, the overall frequency of muscle gain was 15.4%, and muscle was stable in 45.6% of intervals between any 2 scans, which made the maintenance or gain of muscle the predominant behavior. Multinomial logistic regression revealed that being within 90 d (compared with >90 d) from death was the principal risk factor for muscle loss (OR: 2.67; 95% CI: 1.45, 4.94; P = 0.002), and muscle gain was correspondingly less likely (OR: 0.37; 95% CI: 0.20, 0.69; P = 0.002) at this time. Sex, age, BMI, and tumor group were not significant predictors of muscle loss or gain. CONCLUSIONS: A window of anabolic potential exists at defined early phases of the disease trajectory (>90 d survival), creating an opportunity for nutritional intervention to stop or reverse cachexia. Cancer patients within 90 d of death have a low likelihood of anabolic potential.

Sarcopenia as a prognostic index of nutritional status in concurrent cirrhosis and hepatocellular carcinoma.

BACKGROUND AND AIMS: Abnormal body composition such as severe skeletal muscle depletion or sarcopenia has emerged as an independent predictor of clinical outcomes in a variety of clinical conditions. This study is the first study to report the frequency and prognostic significance of sarcopenia as a marker of nutritional status in patients with hepatocellular carcinoma (HCC). METHODS: We analyzed 116 patients with HCC who were consecutively evaluated for liver transplant. Skeletal muscle cross-sectional area was measured by CT. Sarcopenia was defined using previously established cutpoints. RESULTS: Ninety-eight patients were males (85%), and the mean age was 58±6 years. Sarcopenia was present in 35 patients (30%). By univariate Cox analysis, male sex (HR, 3.84; P=0.02), lumbar skeletal muscle index (HR, 0.97; P=0.04), INR (HR, 8.18; P<0.001), MELD score (HR, 1.19; P<0.001), Child-Pugh (HR, 3.95; P<0.001), serum sodium (HR, 0.84; P<0.001), TNM stage (HR, 2.59; P<0.001), treatment type (HR, 0.53; P<0.001), and sarcopenia (HR, 2.27; P=0.004) were associated with increased risks of mortality. By multivariate Cox regression analysis, only MELD score (HR, 1.08; P=0.04), Child-Pugh (HR, 2.14; P=0.005), sodium (HR, 0.89; P=0.01), TNM stage (HR, 1.92; P<0.001), and sarcopenia (HR, 2.04; P=0.02) were independently associated with mortality. Median survival for sarcopenic patients was 16±6 versus 28±3 months in nonsarcopenic (P=0.003). CONCLUSIONS: Sarcopenia is present in almost one third of patients with HCC, and constitutes a strong and independent risk factor for mortality. Our results highlight the importance of body composition assessment in clinical practice.

Severe muscle depletion in patients on the liver transplant wait list: its prevalence and independent prognostic value.

As detected by cross-sectional imaging, severe muscle depletion, which is termed sarcopenia, holds promise for prognostication in patients with cirrhosis. Our aims were to describe the prevalence and predictors of sarcopenia in patients with cirrhosis listed for liver transplantation (LT) and to determine its independent prognostic significance for the prediction of waiting-list mortality. Adults listed for LT who underwent abdominal computed tomography/magnetic resonance imaging within 6 weeks of activation were retrospectively identified. The exclusions were hepatocellular carcinoma, acute liver failure, prior LT, and listing for multivisceral transplantation or living related LT. Sixty percent of the 142 eligible patients were male, the median age was 53 years, and the median Model for End-Stage Liver Disease (MELD) score at listing was 15. Forty-one percent were sarcopenic; sarcopenia was more prevalent in males versus females (54% versus 21%, P < 0.001) and increased with the Child-Pugh class (10% for class A, 34% for class B, and 54% for class C, P = 0.007). Male sex, the dry-weight body mass index (BMI), and Child-Pugh class C cirrhosis (but not the MELD score) were independent predictors of sarcopenia. Sarcopenia was an independent predictor of mortality (hazard ratio = 2.36, 95% confidence interval = 1.23-4.53) after adjustments for age and MELD scores. In conclusion, sarcopenia is associated with increased waiting-list mortality and is poorly predicted by subjective nutritional assessment tools such as BMI and subjective global assessment. If this is validated in larger studies, the objective assessment of sarcopenia holds promise for prognostication in this patient population.