Biochemical indices to evaluate nutritional support for malignant disease.

Malignant diseases are often complicated by malnutrition, and nutritional support is often indicated. Nutritional support should be evaluated primarily by improved clinical outcome. During nutritional support as artificial nutrition, monitoring is of paramount importance. Several biochemical markers are frequently used to monitor nutritional status. Most widely used are serum levels of albumin, transferrin, and transthyretin which are subnormal in malnutrition. Unfortunately, monitoring nutritional support by biochemical indices in malignant disease is complicated by the pathophysiology of cancer related malnutrition. Systemic inflammation is central in this context as it perturbs most of the traditional biochemical indices, and is inversely correlated to survival. In addition, systemic inflammation explains variations in body composition. Thus, the most important biochemical index to be measured in malignant disease is the assessment of systemic inflammatory response, preferably by high-resolution CRP, and if normal, common biochemical indices such as albumin, transferrin or transthyretin might be used. Preferentially, indices with high turnover should be used. IGF-1 is an index well suited for assessing nutrition support in conventional malnutrition, but its use in malignant disease is still unproved. If APPR is prevalent, methods detecting changes in body composition, performance or physical activity might offer better options to evaluate nutritional support.