Cancer-related anorexia-cachexia syndrome (CACS) is a hypercatabolic state, characterized by reduced appetite and weight loss due to ongoing loss of skeletal muscle mass and adipose tissue. CACS occurs mainly in patients with advanced cancer; thus, weight loss in CACS is often associated with poor prognosis and decreased survival. A large number of studies have been conducted on various pharmacologic agents for palliation of cancer-related anorexia. The purpose of this article is to review the pre-existing pharmacologic agents used for CACS and to evaluate the evidence from current studies on each pharmacologic agent. First, appetite stimulants such as corticosteroids, progestins, cyproheptadine, and cannabinoid have been shown to be beneficial by improving appetite and helping with weight changes even if they had no effect on survival rate. Several other agents with anti-inflammatory effects (e.g., eicosapentaenoic acid, thalidomide, and melatonin), prokinetic agents (e.g., metoclopramide), anabolic agents (e.g., androgens and growth hormone), antipsychotics (e.g., mirtazapine and olanzapine), and antiemetics have also been studied in patients in CACS; however further investigations would be required to confirm the beneficial effects.

Glutamine is the most abundant amino acid, composed of more than 50 percent of free amino acid in the human body. It had been regarded as a conditional essential amino acid and its concentration is markedly reduced in critically ill patients with trauma, burn, or sepsis. From the early 1990s, many parenteral glutamine studies on critical illness have reported the benefits in mortality, infection, and length of stay. However, its clinical efficacy was based on out-of-date, smaller, single-center studies. Clinical effects of parenteral glutamine have shown no benefits or even harms in recent clinical trials and meta-analysis. Furthermore, it has challenged the hypothesis that low plasma glutamine concentration was associated with poor outcomes in critically ill patients. Although many studies showing the efficacy of glutamine have been reported, parenteral glutamine supplementation may be harmful in patients with multiorgan failure or baseline kidney dysfunction. Further studies should be conducted to identify the use of glutamine supplementation in combination with parenteral and enteral nutrition or enteral/oral nutrition alone, specific adult or pediatric patients, the appropriate time and doses for administration of glutamine, cost-benefit analysis, and the exact mechanisms of action.

Accurate measurement of body composition between lean and adipose tissue mass and distribution of lipid burden may be important in the care of nutritional problems in patients observed in clinical practice and the measurement of outcomes in clinical research. In this review, we discuss the most accurate imaging methods for use as clinical tools in measurement of body composition and distribution. Dual-energy x-ray absorptiometry (DXA) is a non-invasive technique for assessment of body composition, and the radiation exposure is relatively minimal. However, measurements are influenced by thickness of tissue and lean tissue hydration. Computed tomography (CT) is a gold-standard imaging method for body composition analysis at the tissue-organ level, however the radiation generated by the CT scan is relatively high, thus it should not be considered for a measurement, which can be repeated frequently. Magnetic resonance imaging (MRI) has been a useful modality in the assessment of body composition changes in various clinical studies. However, limitations of MRI for assessment of body composition are related to its high cost and technical expertise necessary for analysis. Proper methods for measurement of body composition in specific medical situations like sarcopenia should be evaluated for determination of comparative validity and accuracy, within the context of cost-effectiveness in patient care. In conclusion, an ideal body imaging method would have a significant utility for earlier detection of nutritional risks, while overcoming the limitations of current imaging studies such as DXA, CT, and MRI.