Serum leptin levels during cancer chemotherapy

Research advances on how metformin improves memory impairment in "chemobrain"

Cognitive impairment caused by chemotherapy, referred to as "chemobrain," is observed in approximately 70% of cancer survivors. However, it is not completely understood how chemotherapy induces cognitive dysfunction, and clinical treatment strategies for this problem are lacking. Metformin, used as a first-line treatment for type 2 diabetes mellitus, is reported to reduce the effects of chemobrain. Recently, several studies have examined the effect of metformin in rescuing chemobrain. This review discusses recent clinical/preclinical studies that addressed some mechanisms of chemobrain and evaluates the effect of metformin in rescuing chemobrain and its potential mechanisms of action.

Metabolic sequelae of cancers (excluding bone marrow transplantation)

The pathogenesis of cancer anorexia/cachexia is still unclear, partly explaining why its treatment remains disappointing. Anorexia plays a central role but cancer cachexia is more complex than chronic starvation. One of the key differences is the preferential mobilization of fat and the sparing of skeletal muscle in simple starvation compared to an equal mobilization of fat and skeletal muscle in cancer patients. An increase in basal energy expenditure also appears to play a contributory role in many patients. Cytokines, essentially but not exclusively tumor necrosis factor-alpha, play an essential pathogenic role and the syndrome can be compared to a low grade chronic inflammatory state. Parenteral nutrition could facilitate the administration of complete doses of chemotherapy or radiotherapy but no significant survival benefit or decrease in treatment-induced toxicity have been demonstrated in prospective randomized trials. The gut should have the preference for nutritional support. Percutaneous endoscopic gastrostomy is used more and more often in patients with a functionally intact gastrointestinal tract, especially in patients with head and neck cancer. Progestational drugs can to some extent stimulate appetite, food intake, energy level, increase weight and decrease the severity of nausea and vomiting. However, pharmacological treatment of cancer cachexia remains disappointing and more trials with anticytokine drugs, anabolic agents or polyunsaturated fatty acids should be conducted.

The syndrome of anorexia-cachexia

Cancer anorexia/cachexia is a major clinical problem, especially in advanced cancer patients. Its pathogenesis is quite complex. Anorexia plays a central role, but cancer cachexia is more complex than pure chronic starvation. One of the key differences is the preferential mobilization of fat and the sparing of skeletal muscle in simple starvation compared with an equal mobilization of fat and skeletal muscle in cancer patients. An increase in basal energy expenditures seems to play a contributory role in many patients. Cytokines, essentially but not exclusively tumor necrosis factor alpha, play an essential role, and the syndrome can be compared with a low-grade chronic inflammatory state. As it is in most fields in medicine, prevention is more efficacious than treatment, and, to avoid the final and dramatic stages of cancer cachexia, adequate nutritional advice and support must be provided sufficiently early. Parenteral nutrition could facilitate the administration of complete doses of chemotherapy or radiotherapy, but no significant survival benefit or decrease in treatment-induced toxicity have ever been demonstrated in prospective randomized trials. The gut should always be used if at all possible. Percutaneous endoscopic gastrostomy is used increasingly in patients who cannot eat but who have functionally intact gastrointestinal tracts, especially in patients with head and neck cancer. Eight randomized, double-blind, placebo-controlled studies have demonstrated that progestational drugs can somewhat stimulate appetite, food intake, and energy level; increase weight in many patients; and often decrease nausea and vomiting severity; however, pharmacologic treatment of cancer cachexia remains disappointing, and more trials with anticytokine drugs should be conducted.