Nutritional support in the cancer-bearing host: Effects on host and tumor

Abstract

Cancer patients have the highest prevalence of malnutrition of any group of hospitalized patients. The potential causes of this malnutrition are numerous, as elements of both starvation and stress are evident in the cancer-bearing host. The presence of the tumor alone may lead to reduced intake of nutrients and treatment modalities of surgery, chemotherapy, and radiation therapy further exacerbate nutritional deficits. It is clear that the tumor requires energy substrates to grow, and that these substrates are exacted from the host. Animal studies identify progressive nutritional depletion concomitant with increasing tumor growth during ingestion of a regular diet. This appears predominantly due to reduced dietary intake in addition to host metabolic alterations. In animal/tumor models deliberate dietary protein depletion results in severe host weight loss, but also causes diminished tumor growth rates. Dietary manipulation in these animal/tumor models have demonstrated methods of improving tumor response to chemotherapy by manipulation of tumor growth rates. In addition, drug-pharmacokinetics have been altered by dietary manipulation. However, data from animal/tumor models are not directly applicable to man since the tumor in animals usually results in the death of the host within six to eight weeks. Nevertheless, controlled laboratory studies in animals provide basic metabolic information which promotes understanding of host/tumor relationships in man. In cancer patients malnutrition has prognostic value, leads to a distortion of body composition with erosion of body protein and fat stores, and compromises the delivery of adequate therapy. There is no direct objective evidence of accelerated tumor growth in humans with cancer who receive nutritional support as part of their treatment regimen. The host benefits to the extent that body composition is at least maintained during the period of nutritional repletion. Thus, nutritional support provides support to the patient during periods of treatment and dietary deprivation. No improvement in the tumor's response to therapy, however, has been demonstrated by this approach.

Nutrition and hydration for terminal cancer patients in Taiwan

“…However, later randomized controlled studies have suggested that aggressive nutritional therapy has no impact on tumor response, toxicity, or survival [1,9]. Moreover, one animal study showed that aggressive nutritional therapy could significantly increase tumor growth [20]. It is widely recognized that the outcome measures of aggressive nutritional therapy for patients with advanced cancer should also include the patients' overall quality of life [14].…”

Correlation between Plasma Glucagon-Like Peptide 2 Levels and Proliferative Makers in Small Intestinal Injury in Rats Induced by Methotrexate Administration

“…Moreover, patients with advanced malignancy often suffer from malnutrition, which increases toxicity and decreases tumor responses to treatment, 2) and such conditions can be dose limiting in therapeutic regimens. A method for prediction of adverse reactions to chemotherapy is thus needed to avoid their occurrence.…”

Metabolic alteration in patients with cancer: Nutritional implications

“…[71][72][73] Numerous tumor-bearing animal studies have demonstrated that tumor growth and metastasis can be significantly stimulated during periods of nutritional support. 74 Therefore, the ability of nutritional therapy to reduce morbidity and mortality in patients with cancer should be demonstrated before its widespread use is adopted in the clinical setting.…”