Nutritional support and tumour growth in humans: A narrative review of the literature

SummaryBackground & aimsAlthough there is an experimental evidence that intravenous administration of nutrients may increase tumour growth in animals, data on humans are scanty and sparse. The purpose of this study was to review the literature that has specifically investigated the effects of nutritional support on tumour growth in cancer patients.MethodsA review of the literature identified 12 suitable papers representing a total of 140 patients receiving nutritional support versus 84 controls. The studies were classified as randomized clinical trials (5), comparative non-randomized clinical trials (3) and trials with patients who were controls for themselves (4). The indicators of tumour growth used in the studies included the DNA index, ornithine decarboxylase activity, flow-cytometric DNA distribution, and the labeling index with tritiated thymidine or bromodeoxyuridine.ResultsIncreased tumour growth was not observed in control patients without nutritional support but it was reported in 7 out of 12 studies in patients receiving nutritional support.ConclusionsProviding nutritional support to cancer patients may cause tumours to grow more quickly. However, nutritional support is recommended when nutritional status is so compromised that patients are at high risk for complications or cannot comply with the oncologic therapy as reported in the clinical practice ESPEN guidelines.