Nutrition in Cancer
What is cancer cachexia?
Cancer cachexia is characterized by a chronic, progressive, involuntary weight loss which is poorly or only partially responsive to the common nutritional support.
It is often associated with anorexia, early satiation and asthenia.
The metabolic derangements include insulin resistance, increased lipolysis and normal or increased lipid oxidation with loss of body fat, increased protein turnover with loss of muscle mass and an increase in production of acute phase proteins.
Cancer cachexia could be prevented or at least delayed by means of early nutritional
intervention.
How do you distinguish cancer cachexia from simple undernutrition?
It is difficult to distinguish the two as both causes weight loss and anorexia. However, simply undernourished patients tend to save their protein mass and respond quite well to the nutritional support if their general status is not compromised in an irreversible way. On the contrary, cancer cachectic patients have depletion of both the fat and the muscular mass (with preservation of their central protein mass). Further, they do not get substantial benefit from the nutritional support.
When should nutritional assessment be done in cancer patients?
Nutritional assessment of cancer patients should begin with tumour diagnosis and be repeated at every visit in order to initiate a nutritional intervention early, before the general status is severely compromised and becomes irreversible.
Does nutritional status influence the clinical course and the prognosis?
Yes. Poor nutritional status is associated with reduced quality of life, lower activity level,
increased treatment-related adverse reactions, reduced tumour response to treatment and reduced survival.
What are the energy and substrate requirements in cancer patients?
- Energy requirements are similar to healthy subjects-20-25 Kcal/Kg /day for bedridden and 25-30 Kcal/Kg/day in ambulatory patients.
- Protein- minimum 1 g/KgBW/ and a target supply of 1.2–2 g/KgBW/day
- For short term PN- no specific formulation is needed. However, there is some suggestion for using a high percentage of lipids in the admixture (~50% of non-protein energy requirement, as fat is efficiently utilised as a fuel source in cancer patients and glucose oxidation is reduced. An even higher than 1 to 1 fat to glucose energy ratio may be tried when pleural or peritoneal effusions are limiting approach as glucose infusions can precipitate or worsen effusions.
What are the indications for PN?
Inadequate (<60% of estimated energy expenditure) enteral intake for more than 7-10 days
Is PN recommended in incurable cancer patients?
PN may be recommended in incurable cancer patients who cannot be fed orally or
enterally
- if they are estimated to die prior from starvation than from tumour progression, mainly because of (sub) obstruction and aphagia,
- if their performance status and quality of life are acceptable, and
- if there is a strong patient and family motivation for a demanding procedure which has not yet been fully validated in its results.
Does PN ‘‘feed’’ the tumour?
Probably yes, but without known deleterious effects on the outcome and thus this consideration should have no influence on the decision to feed a cancer patient when PN is clinically indicated.
Ref
