L4 - Nutrition & Cachexia Flashcards
Why is the site of cancer important to consider when managing cancer?
Cancers near the head & neck will impact how patients eat/chew e.g oral cancer vs breast cancer
How can radiotherapy affect management of cancer?
If radiotherapy is given for the head/neck, it may have significant impacts on the ability to eat & the sense of taste
Why are side effects of treatment important to consider when managing cancer?
Nausea & vomiting is common with chemotherapy –> may hinder ability to keep food down
Why is patient age important to consider when managing cancer?
Elderly patients tend to be poorly nourished & frail –> may not be able to tolerate treatment well
What is one of the most important markers of morbidity, mortality, & ability to tolerate treatment?
Weight loss
Which cancers have the most acute & chronic weight loss?
Cancers relating to GI tract
–> but these cancers also tend to respond to nutritional support best
What is the relationship between body weight loss & total body protein loss?
Lean body mass = lean functional tissue mass
Whenever weight is lost, protein is also lost –> important to try maintain weight
Proportion of weight loss from original weight will indicate median survival time
What is cachexia?
Wasting away of the body
What is the pathophysiology of cachexia? (FOUR steps)
- Tumour’s drive to produce pro-inflammatory cytokines
- Increased pro-inflammatory response (interleukins, TNFa etc.)
- Endocrine dysfunction
- Increased protein degradation, decreased protein synthesis
What FOUR things does cachexia lead to?
Decreased survival
Alterations in body image
Decreased function & strength
Caregiver distress
What is precachexia?
Weight loss <5%
Anorexia & metabolic change
What is cachexia? (stages)
Weight loss >5%, may have sarcopenia (decrease in skeletal muscle) or decreased BMI
Reduced food intake
Systemic inflammation
What is refractory [resistant] cachexia?
Cancer disease procatabolic & unresponsive to treatment
Low performance score
< 3 months survival
How is fat breakdown caused?
Tumour –> lipid mobilising factor –> fat breakdown
How is anorexia caused?
Tumour –> cytokines –> hypothalamus –> anorexia
How is increased energy expenditure caused?
Tumour –> cytokines –> hypothalamus –> increased energy expenditure
How is the inflammatory response caused?
Tumour –> cytokines –> liver –> inflammatory response
Tumour –> hormonal changes –> skeletal muscle –> liver –> inflammatory response
How is protein breakdown caused?
Tumour –> proteolysis inducing factor –> skeletal muscle –> protein breakdown
Is glucose tolerance in cachexia increased or decreased?
Decreased
Is insulin sensitivity in cachexia increased or decreased?
Decreased
Is glucose turnover in cachexia increased or decreased?
Increased –> tumour uses glucose to develop
Is hepatic gluconeogenesis in cachexia increased or decreased?
Increased
Is serum lactate level in cachexia increased or decreased?
Increased –> more lactic acid produced for extra energy
Is lactic acid cycle level in cachexia increased or decreased?
Increased –> more lactic acid produced for extra energy
Is serum triglyceride level in cachexia increased or decreased?
Increased –> mobilisation of fat stores
Is protein turnover in cachexia increased or decreased?
Increased –> proteolysis inducing factor –> breakdown of proteins to produce energy for tumour
Is skeletal muscle catabolism in cachexia increased or decreased?
Increased –> proteolysis inducing factor –> breakdown of proteins to produce energy for tumour
Which treatment is weight loss most common in?
All
Chemotherapy
Radiation
Surgery
Immunotherapy
What treatment is fatigue most common in?
All
Chemotherapy
Radiation
Surgery
Immunotherapy
What treatment is nausea & vomiting most common in?
Chemotherapy
Radiation
Surgery
NOT immunotherapy –> more targeted
What treatment is oral mucositis most common in?
Chemotherapy –> systemic cytotoxic
Radiation –> local
Immunotherapy
NOT surgery –> cells in mouth not damaged since surgery is localised
What treatment is taste disturbance most common in?
Chemotherapy
Radiation
What treatment is constipation most common in?
Chemotherapy
How does physical impairment of swallowing contribute to malnutrition in cancer? (FOUR points)
Effects on chewing/swallowing mechanisms
Reduction in saliva production (xerostomia)
Radiation-induced or chemotherapy-induced mucositis (painful to eat)
Surgical interruption of swallowing mechanism
How does alterations in physiology contribute to malnutrition in cancer? (THREE points)
Malabsorption/maldigestion due to tumour or therapy
Constipation/GI immotility
Removal of part of GI tract
How does insufficient dietary intake contribute to malnutrition in cancer? (TWO points)
Suppression of appetite (nausea, vomiting)
Food aversion
What is enteral feeding?
Any method of feeding involving GI tract to deliver nutrition
May involve oral or NG tube
How is food delivered parenterally?
Simplest building block
Protein - amino acid
Carbohydrate - glucose
Fat - fatty acids, triglycerides & combination
Micronutrients - vitamins, minerals (eg. iron, calcium, zinc), trace elements (eg. boron)
Fluid balance - electrolytes
