Cancer Cachexia Flashcards
What are the effects of malnutrition and weight loss caused by altered metabolism and reduced intake in cancer?
- Decreased quality of life
- Decreased response to treatment
- Decreased survival
What are the benefits of assessing nutrition status in individuals with cancer?
- Early identification of patients at risk allows for early intervention
- Improves patient well-being, survival, immune function, and reduced morbidity
Define cachexia.
- A complex metabolic syndrome ASSOCIATED with underlying illness and characterized by loss of muscle with or without loss of fat mass
- The prominent feature is weight loss
What is the difference between cachexia and cancer?
Cachexia is a syndrome, while cancer is a disease
What is a syndrome?
Groups several conditions together, and may not be diagnosed as easily
What leads to muscle wasting in cancer patients?
- Inflammation
- Insulin resistance
- Hypogonadism
What leads to fat loss in cancer patients?
- Anorexia
- Inflammation
What are consequences of muscle wasting?
- Increased fatigue
- Increased treatment-induced toxicity
- Decreased host response to tumours
- Decreased performance status
- Decreased survival
What is sarcopenic-obesity?
Obesity with depleted muscle mass
What leads to an increased treatment-induced toxicity in cancer patients with muscle wasting?
The drugs are designed based on body surface
What is the overall prevalence of cancer cachexia?
50 to 80%
Which cancers have a more frequent prevalence of cancer cachexia?
- Upper gastro-intestinal cancer: 80%
- Upper gastric and pancreatic cancer: 83-87%
- Head-and-neck cancers render food intake more complicated
- Lung cancer: 60% (altered metabolism)
What are the two main components of the onset of cachexia?
- Metabolic change (hypercatabolism and hypoanabolism)
- Reduced food intake
Differentiate hypercatabolism and hypoanabolism.
- Hypercatabolism: increased protein degradation
- Hypoanabolism: less response to anabolic stimuli
Differentiate primary and secondary anorexia.
- Primary: driven by physiological changes due to illness itself
- Secondary: secondary to the treatment of the disease (chemotherapy, radiotherapy)
What is sarcopenia?
- Decreased muscle mass, which is typically associated with aging
- May be observed despite a lack of weight change
How does the resting energy expenditure differ between starvation and cachexia? What does that induce?
- Starvation reduces REE
- Cachexia increases REE
- The loss of weight is more rapid in cachexia than in starvation
Why is it so important to diagnose cachexia early on?
Because nutritional support provided during the refractory period (last 3 months before death) is not fruitful
Differentiate positive and negative acute phase proteins.
- Positive: plasma concentrations increase by over 25% during stress
- Negative: plasma concentrations decrease by over 25% during stress
Which protein is largely measured to indicate a positive acute phase response?
C-reactive protein
What is the acute phase response modulated by?
Cytokines
What pro-inflammatory cytokines are found in cancer?
- TNF-a
- IL-1
- IL-6
- IFN-gamma
What are the effects of cytokines on skeletal muscle wasting?
- Anorexia (reduced substrate supply)
- Direct catabolic effect on muscle
What are the effects of cytokines on the liver?
- Increase in urinary nitrogen loss (because of increased substrate demands)
- Increase in acute phase proteins
What components of energy expenditure does cancer cachexia change?
- Increases resting energy expenditure
- Decreases thermic effect of feeding
- Decreases physical activity energy
Cancer cachexia is a (hypo/hyper)metabolic syndrome.
hypermetabolic (spend less than 600 calories less than healthy individuals)
What are metabolic alterations in cancer cachexia?
- Decreased responsiveness to anabolic factors
- Increased concentration of catabolic factors
- Mobilization of lipids from adipose tissue stores
- Glucose is the preferred fuel for tumours
- Insulin resistance
- Increased gluconeogenesis
- Increased synthesis of acute-phase proteins
What are the three pathways of proteolysis?
- Lysosomal (caspases)
- Calcium-dependent (calpains)
- ATP-dependent ubiquintin-proteosome
What is the link between ubiquintination and inflammation?
- Inflammatory cytokines (TNF-a and IL-1) increases the expression of genes encoding UbqE3
- Induces a greater quantity of proteolysis
What source of energy do tumours feed on? What does it produced?
- Glucose
- Produces lactate
- Recycled via the Cori cycle
What may early satiety result from?
- Reduced GI motility
- Increase in gastric emptying
- Opioid analgesics
What assessment methods are used to identify the severity of cancer cachexia?
- Analysis of the presence of anorexia
- Catabolic drive (C reactive protein)
- Muscle mass and strength
What are the three main aspects of treating cancer cachexia?
- Nutritional counselling
- Exercise
- Pharmacological treatment
What are the goals of therapy to cancer cachexia?
- Stabilizing weight, and attempt to increase lean body mass
- Predispose to a better response to radio or chemotherapy
- Increase immunocompetence
What route of feeding should be used?
Oral
When would you use enteral feeding?
Obstructions, gastric atony, or limited absorptive capacity
When is parenteral nutrition not recommended?
Advanced cancer patients receiving chemotherapy, nor the advanced stages of cancer cachexia
What is a promising nutrition therapy for cancer cachexia? Why?
- Omega-3 fatty acid
- Anti-inflammatory effects and anabolic properties
What has the best chance of successfully treating cancer cachexia?
- Physical exercise
- Pharmacological agents
- Individual nutritional counselling
- Early intervention
