Role of nutrition in gastrointestinal oncological patients.

A paradox exists in the relationship between nutrition and cancer. Excessive dietary intake of nutrients and decreased physical activity represent two modifiable factors responsible for cancer development, namely for cancers of the gastrointestinal (GI) tract, and the present epidemics of obesity and diabetes is likely to increase the incidence of GI and metabolically-derived liver in the next few years. At the same time, in subjects diagnosed with cancer, malnutrition represents a risk factor of poor outcome following surgical resection, as well as of increased toxicity following chemo- and radiotherapy. Any effort should be made to modify the current trend of obesity for cancer prevention, as well as to provide enteral or parenteral nutritional support in cancer patients, to cope with nutritional needs and prevent cancer-related cachexia.