title: Metabolic and nutritional implications of cancer and chemotherapy
Creators: name: Willox, Joanne Christine
Publisher: name: University of Glasgow
Year: 1984
Subjects: subject: Pharmacology.

description: Cancer and chemotherapy are well known to cause metabolic and nutritional alterations in patients; the culmination of these being the syndrome of cancer cachexia. Theories abound to explain the causes of the altered metabolism, however many of the problems encountered in the cancer patient remain unresolved. The aims of this thesis are to explore, in more detail, some of these metabolic and nutritional problems. The problem of nutritional assessment was considered, and dietary histories, clinical evaluation and biochemical estimations of nutritional deficiencies were compared and contrasted in a search for the best, easiest and most reliable method of nutritional assessment for the cancer patient. The best method of assessing patients was found to be a combination of all three types of evaluation. Each type of assessment broadly agreed with the others, however clinical and biochemical evaluations of nutritional state tended to reflect long-standing deficiencies, while 24 hour dietary recall histories could be used to predict potential nutritional problems. Twenty-four hour dietary recall histories with computer analysis used on several occasions allow fluctuations in dietary intake and hence nutritional state to be recorded, and provide a fast, easy and reliable way of evaluating present nutritional state and anticipating and correcting future nutritional problems. The effects of cancer and chemotherapy on nutritional and metabolic status of cancer patients and tumour-bearing animals were considered in a number of studies. Muscle biopsies were performed on cachectic cancer patients and showed considerable disruption of muscle fibres with particularly striking changes seen in the mitochondria. These changes were shown to be unique to cancer patients, illustrating the specific metabolic alterations in this group. A preliminary study to investigate the problems of dry mouths, with difficulty in chewing and swallowing food, and changes in taste sensations, anorexia, and decreased enjoyment of food, looked at saliva composition and production. Cancer patients were found to have decreased saliva volumes, amylase content, lysozyme and IgA content and increased microbacteria and yeasts present in the saliva, compared to healthy controls. Patients followed over three months from initial chemotherapy showed decreasing saliva flow rates and increasing microflora colonisation of the mouth over this time. Cisplatin, Adriamycin and Mitomycin-C were particularly implicated in microorganism colonisation; Cyclophosphamide and Methotrexate were more likely to produce decreased saliva volumes and dry mouths. Further work is required to correlate the incidence of dry mouths, altered taste sensations and anorexia with the changes found in saliva production and composition. The results obtained, however, confirm that there is decreased saliva flow in cancer patients receiving chemotherapy; and that the mouth harbours organisms which are potentially virulent if host defences are impaired. Metabolic consequences of tumour growth and chemotherapy were considered in studies using Wistar rats. The animals were given tumour alone, tumour plus Cyclophosphamide or Cisplatin, or drug alone. All showed metabolic alterations with weight loss, decreased carcass nitrogen content, decreased plasma protein, albumin and iron content, increased levels of ketone bodies and deranged liver enzymes. The tumour produced the greatest metabolic insult; the drugs also produced deterioration in metabolic state. The tumour and drug groups shoved less metabolic upset, demonstrating the beneficial effects of response to treatment; where there is no response to treatment there are increased metabolic problems caused by cumulative effects of drugs and tumour. Further studies should examine the use of prednisolone over longer periods; and compare prednisolone with other appetite stimulants. In conclusion, this thesis has examined some of the effects of cancer and chemotherapy on nutrition and metabolism; many of the results obtained beg further studies, and there remains a lot of work to be done to fully understand the nutritional and metabolic implications of cancer and its treatment. (Abstract shortened by ProQuest.).