CANCER CACHEXIA AND DEPRESSIVE STATES - A NEURO-ENDOCRINE-IMMUNOLOGICAL DISEASE

Plasma 5-hydroxytryptamine (serotonin), tryptophan, neopterin and cort isol levels were measured in patients with depressive cancer cachexia and in healthy controls during the same time period. Patients with adv anced cancers had significantly raised neopterin, a marker of endogeno us gamma-interferon (IFN-gamma) production, and cortisol values, but d ecreased serotonin and tryptophan levels. Much work has been done to e lucidate the possible role of serotonin in depressive states. IFN-gamm a induces a high level of indoleamine dioxygenase (IDO), a tryptophan degrading enzyme, and high cortisol levels induce high tryptophan oxyg enase activity, which in turn increases metabolism along the tryptopha nnicotinic acid pathway. These results suggest that persistent immune activation and intense adrenal activity occur In patients with cancer cachexia, resulting in disorders involving tryptophan metabolism follo wed by depression in cancer cahexia.