Cancer - Nutrition Support in Heamatological Malignancies Flashcards
What is the impact of haematological malignancies on nutritional status?
The cancer itself is rarely associated with a deterioration of nutritional status.
Deterioration of nutritional status often occurs as a result of the deleterious effect of antineoplastic treatment.
Therefore even previously healthy/well nourished patients are at risk of nutrient deficiencies and malnutrition so nutritional intervention is necessary.
Treatments often include aggressive antineoplastic regimens (drugs that kill cancer cells) such as high-dose chemotherapy, and stem cell transplantation.
The impact on nutritional status varies and can be disease-treatment related impairment such as:
- nutrient losses
- nutrient malabsorption
- altered energy/protein metabolism
What are the goals of nutritional intervention in haematological malignancies?
Overall goal:
Maintenance of nutritional status
Other targets:
- improved tolerance to chemotherapy/radiotherapy
e.g., reduce mucositis
- maintenance of immunocompetence
e.g., reduce chance of infection/complications
What is Haematopoietic stem-cell transplantation?
Describe the two types of Haematopoietic stem-cell transplantation?
- What are the key pros/cons of each?
(previously known as bone marrow transplant)
Administration of high dose chemo/radiotherapy followed by intravenous infusion of haematopoietic stem cells.
Two types:
Allogenic (Allo-HSCT)
- the transfer of stem cells from a donor to a recipient.
- carries high risk of GVHD
Autologous (a-HSCT)
- using ones own stem cells
- no chance of GVHD
- risk of tumour cell contamination in the graft
Haematopoietic stem cells can come from bone marrow, umbilical cord blood, or peripheral blood.
How is nutritional status assessed in patients receiving HSCT?
Assessment of nutritional status is required in all patients receiving HSCT.
There is no gold standard in evaluating the nutritional status of HSCT patients:
screening tools e.g., NRS 2002, MUST are used alongside anthropometry and functional tests e.g., grip strength.
Nitrogen balance is the best way to assess nutritional status in HSCT patients.
It is a direct expression of the imbalance between protein breakdown and synthesis.
However urine collection may be difficult plus vomiting/diarrhoea can make nitrogen loss calculation inaccurate.
Biochemical assessment not a good reflection of nutritional status.
Anthropometric assessment can be wrongly influenced by fluid and electrolyte imbalances.
DescrIbe the role of artificial feeding following HSCT.
What are the benefits of PN over EN in HSCT patients?
Chemotherapy induced GI impairment prevents optimal nutrient intake and absorption, therefore chemotherapy followed by HSCT is a major application for PN due to the many gastrointestinal disturbances associated with treatment itself and treatment complications.
- Parenteral nutrition allows more accurate modulation and provision of fluids, electrolytes, and macronutrients.
- Cant always place a GI tube due to mucositis - however it is possible to safely insert a GI tube with up to grade 2 mucositis which is becoming common practice.
- Majority of patients undergoing HSCT have a central venous catheter placed, through which PN can be given.
PN is more expensive than EN and therefore generally only started when absolutely necessary, when oral feeding falls below 60-70% of requirements for 3 days.
Describe the benefit of glutamine supplementation in HSCT patients.
Glutamine is a primary fuel for enterocytes and gut-associated lymphoid tissue.
Glutamine supplementation can mitigate GI impairment caused by treatment.
- minimises intestinal mucosal atrophy associated with PN
- reduce liver damage caused by chemo/radiotherapy in HSCT patients.
Dose of around 0.6g/kg BW/day is appropriate.
What are the clinical and nutritional consequences of the therapeutic interventions for HM?
- Chemo/radiotherapy
- HSCT
Chemo/radiotherapy:
- Mucositis of the GI tract
Haematopoietic Stem Cell Transplantation:
- Graft Versus Host Disease (GVHD):
- Altered Metabolism
How does HSCT affect metabolism?
HSCT can affect energy, protein, lipid and CHO metabolism.
Can also effect body composition and vitamin status.
Energy:
HSCT patients have increased energy needs -
energy and nutrient demands are increased due to:
- catabolic effect of cytoreductive therapy
- GVHD in allo-HSCT patients
- presence of sepsis
- optimal blood cell reconstitution
Carbohydrate metabolism:
- Administration of steroids and/or septic complications can negatively affect CHO metabolism and induce impaired insulin tolerance.
- HSCT itself can negatively affect pancreatic beta-cell function and induce glucose intolerance/overt diabetes.
Protein metabolism -
Negative nitrogen balance is a common feature in HSCT patients due to intestinal loss (diarrhoea) and catabolic effect on skeletal muscle due to both disease, treatment and possible complications.
Lipid metabolism:
- Abnormalities in lipid metabolism are uncommon in early stages of HSCT.
- Patients with long term GVHD may have elevated serum-cholesterol and triglyceride concentrations due to cyclosporine therapy.
Vitamin status:
- Vit status may be altered due to poor intake and absorption of fat and water soluble vitamins associated with mucositis or GVHD.
- Use of cyclosporine and radiation increases the need for antioxidants.
Body composition changes -
Allo-HSCT patients experience a decrease in body cell mass with no change to body fat or lean body mass, and increased extracellular fluid and decreased intracellular fluid.
Explain the rationale behind the provision of nutrition and metabolic support to HSCT patients.
What are the nutrient recommendations for HSCT patients?
It is known that patients undergoing high dose conditioning regimens are at risk of malnutrition.
10%–50% of all patients receiving HSCT are already undernourished and often have a low BMI.
During and after the HSCT phase, many of the patients continue to lose weight and their nutritional status worsens.
A study examining 544 adult patients undergoing allogenic HSCT found that patients with BMI < 20 kg/m2 had a higher mortality rate.
All patients undergoing HSCT are required to undergo a comprehensive assessment of their nutritional status before the initiation of treatment. Also, their nutritional status should be monitored and re-evaluated throughout the entire HSCT process.
- Nutrition support (ONS, EN & PN) should be given on an individual basis and reviewed regularly.
Nutrition support is frequently given to prevent risk of malnutrition caused by:
- Drug-induced side effects
- Increased nutritional requirements
Nutrient recommendations:
Energy: Can exceed 130-150% BMR
Lipids: 30-40% non protein energy
Protein: 1.4-1.5kg BW per day of standard amino acid solution (can reach up to 2.0 g/kg/day)
What is GVHD?
- What are the nutritional consequences of GVHD?
Graft Versus Host Disease (GVHD):
Leading causes of morbidity/mortality following allo-HSCT
Immunocompetent cells of the graft (stem cells) does not recognise the human leukocyte antigens (HLA) of the recipient cells and attacks them.
Acute GVHD (a-GVHD) - within 100 days of transplant and affects the skin, liver and GI tract.
Late onset a-GVHD - after 100 days of the transplant and has features similar to autoimmune diseases and affects multiple organs.
Nutritional consequences of GVHD:
Can affect oral, oesophageal, hepatic and intestinal function. These all have a knock-on affect on nutrient intake and absorption.
- Large fluid and protein losses can occur if the skin is affected.
- Cholestasis (flow of bile from the liver is slowed or blocked) occurs if the liver is affected.
- Diarrhoea, nausea, vomiting and abdominal pain occur if GI system is affected.
If GVHD occurs in paediatric patients, can impair normal growth and development.
