[The incidence and pathogenesis of cancer anorexia-cachexia syndrome in lung cancer].

The cachexia-anorexia syndrome (CACS) is common and important implication of cancer. It occurs in 30% to 80% cancer patients. At the time of diagnosis of lung cancer CACS is not yet very important problem, but the weight loss increases with progression of the cancer. CACS is characterized by anorexia, weight loss, weakness, impaired immune system and metabolic dysfunction. Weight loss is a potent stimulus to food intake in normal humans. The persistence of anorexia in cancer patients, therefore, implies a failure of this adaptive feeding response. The weight loss in patients with CACS differs from that in simple starvation or anorexia nervosa. Most research effort has focused on the role of cytokines as mediators of CACS. The role of TNF-alpha, IL-1 and IL-6 in CACS development has been evaluated and confirmed in many research, but some investigators suggest that the changes in cytokines' levels could be the result rather than the cause of CACS. A few of the latest studies concentrate on the role of nuclear factor kappa B and prevention of CACS by its inhibitors. CACS is an independent predictor of shorter survival and increases the risk of treatment failure and toxicity.