Ghrelin and leptin levels in cachectic patients with cancer of the digestive organs

Cancer cachexia, a catabolic state characterized by weight loss, occurs frequently in patients with terminal-stage neoplastic diseases. Gastrointestinal hormones and cytokines may be associated with anorexia and wasting in cancer cachexia. This study aimed to examine the mechanism of anorexia in cachectic patients through a prospective investigation of plasma cytokines, ghrelin, and leptin in 16 cachectic patients with cancer of the digestive organs and 10 healthy volunteers. Tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-1 receptor antagonist (IL-1Ra), and ghrelin levels were significantly higher in cachectic cancer patients than in the healthy volunteers, whereas leptin was significantly lower in the cachectic cancer patients. Plasma leptin levels and cytokine levels (TNF-alpha and IL-6) correlated significantly with body mass index (BMI), but plasma ghrelin levels did not correlate with BMI or with the grade of symptoms. Neither weight loss nor the grade of symptoms seemed to be directly associated with the increase in ghrelin levels. Hence, it is considered that the increase in ghrelin levels cannot simply be explained by an increase in ghrelin secretion, suggesting that other mechanisms, such as the decreased inactivation of ghrelin, may also play a role. Further studies are needed to clarify the mechanisms of the increase in ghrelin levels. Additionally, the changes in plasma cytokines (TNF-alpha and IL-6) and leptin in cachectic cancer patients suggest that these molecules may be useful markers for the evaluation of cancer cachexia.