Dr. Paola Persico
The importance of the use of Omega 3 series fatty acids in the nutritional management of the cancer patient was recalled in the recent meeting that took place in Cremona (13/14 October 2007 organized by SIONCOV – Italian Society of Veterinary Oncology – and SIDEV – Italian Society of Veterinary Dermatology).
Among the many topics covered, Dr. Liliana Prola illustrated the problem of cancer cachexia and the importance of nutritional support in the patient with cancer.
WHAT IS NEOPLASTIC CACHEXIA
Cachexia was defined as a set of events that lead to profound alterations in lipid metabolism, protein and glucose resulting in weight loss and deterioration of the organic conditions and the patient’s quality of life, often associated to weakness, anorexia, immune and mental depression.
THE SIZE OF THE PROBLEM
In humans, it has been reported that affects 87% of patients hospitalized with cancer and is believed that the same percentage may be present in pets.
About 80% of human cancer patients become malnourished during the evolution of the disease.
The weight loss, often, is considered an onset symptom, and almost 20% of late-stage cases bring to death for consequences related to nutritional metabolic problems and not directly due to the tumor.
Cachexia seems to hit more patients from tumors of the gastrointestinal tract both for the systemic action of the tumor that for the worsening of the digestive functions.
POSSIBLE NUTRITIONAL IMPLICATIONS OF INTERVENTIONS DESIGNED TO TREAT CANCER
The patient shows, initially biochemical changes (e.g. increased levels of insulin, serum alterations in proteins and lipids) followed by anorexia, weight loss, increase in side effects related to possible courses of chemotherapy, debilitation, weakness.
In Human Medicine it has been found that the metabolic changes persist even after remission of symptoms due to chemotherapy treatments.
In addition to the direct action of the tumor also the different methods of intervention used to treat it (radiation therapy, surgery, chemotherapy and / or in combination) may have a negative impact on the nutritional status of the patient.
THE METABOLIC CHANGES DURING CACHEXIA
The metabolic abnormalities that develop in the course of cachexia may occur before the onset of clinical signs of the disease itself.
What have in common the pathogenesis of cancer cachexia, which is considered a multifactorial problem, is the protein-muscle catabolism (resulting in loss of lean mass) induced by the increase of various cytokines and that induces production of acute phase proteins (such as the C-reactive protein).
Today in Human Medicine is attributed to this mechanism to the production, by the neoplastic cells, a substance the “proteolysis-inducing factor” (PIF Proteolysis Inducing Factor).
This factor acts stealing proteins to the muscles to supply the tumor and it may be thwarted by administering eicosapentaenoic acid (EPA).
From clinical studies in Human Medicine it seems that administration of EPA permits the correction of metabolic disorders related to damage induced by PIF and by cytokines.
Many clinical studies have been conducted in Human Medicine on cancer patients with cachexia which received a dietary supplement enriched in EPA and antioxidants.
These studies demonstrated that the use of integrator in cancer patients with loss of weight is used to stop the weight loss and regain lean mass, inhibits the formation of pro-inflammatory cytokines, improves the patient’s quality of life and in later stages allows a lengthening of survival of 2-4 months compared to untreated patients with food supplementation.
Even in Veterinary medicine in recent decades, food issues related to cancer patients are the subject of interest and research.
The cancer cachexia is a problem that the veterinary increasingly has to deal with in his clinical practice.
The main alterations that are established in a patient suffering from cancer in the course of cancer cachexia are charged to the metabolism of carbohydrates, proteins and lipids.
CARBOHYDRATES: for the ability of the tumor to produce some factors (such as tumor necrosis factor and interleukin 6) that diminish the cellular sensitivity to insulin causing hyperglycemia and hyperinsulinemia.
PROTEIN: it has an excess of protein breakdown which leads to a negative nitrogen balance.
The protein deficit, thus obtained, leads to a deterioration of the immune response, of the gastro-enteric functionality and the healing of wounds.
The most evident symptoms of accentuated protein catabolism are muscle atrophy, hypoalbuminemia, the decrease of the healing ability and the onset of frequent infections.
LIPIDS: the decrease of lipogenesis and increased lipolysis were observed in patients and in mice with cancer cachexia.
In these studies it was found an increase of blood concentrations of free fatty acids, low-density lipoprotein, triglycerides and to an increase in the activity of hormone-dependent lipase and a decrease in endothelial lipoprotein lipase derived from.
A study evaluated the lipid profile of dogs suffering from lymphoma to identify similarities with those reported in other species.
The results showed a significant increase in the concentration of cholesterol, triglycerides, low and high density lipoprotein compared to the control group with healthy animals.
Clinically, it is important to remember that cancer cells find it difficult to use the lipids as an energy resource.
The lipids may in fact continue to be oxidized and thus represent a viable energy source for the organism.
This confirms the hypothesis that foods rich of fat, than those with high concentrations of carbohydrates, can help in the management of animals suffering from cancer.
In the animal model, often used also in Human Medicine as a reference, numerous studies have shown that administration of omega-3 fatty acids inhibit carcinogenesis and tumor growth.
The omega-3 fatty acids (eicosapentaenoic acid, EPA and docosahexaenoic DHA) generally have an inhibitory effect on tumor growth.
Some studies conducted in vivo, have shown that the EPA has a selective effect on tumor cells taking them to death.
Further research has shown that the administration of omega-3 reduces the secretion of tumor necrosis factor -a (TNF-a), interleukin 1-a and interleukin-2, which are important mediators of the cachectic process and play an also critical role as tumor growth factors.
The role of the different components of the feed ration, both macronutrients (fats, proteins and carbohydrates) and / or micronutrients (vitamins, minerals, fatty acids and amino acids), it is increasingly being studied and it starts to show how the nutritional treatment can positively and profoundly affect the quality of life of animals suffering from cancer.
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