Diminished quality of life in patients with cancer correlates with tryptophan degradation.

PurposeQuality of life (QoL) is frequently impaired in patients suffering from malignant disease. Disturbed metabolism of neurotransmitter serotonin might be crucially involved, and serotonin-precursor tryptophan is degraded during pro-inflammatory immune response. In this study, we compared QoL and fatigue self-rating scores of patients with various types of malignancy with tryptophan metabolic changes and immune activation status.MethodsVenous blood was collected from 146 patients with gastrointestinal tumors (n = 43), hematological malignancy (n = 40), gynecological neoplasms (n = 26), lung cancer (n = 20) and from tumors of other localization (n = 17).ResultsQoL was significantly reduced in patients suffering from progressive tumor disease in comparison to stable or remitting disease, also feeling of fatigue was increased (both P ConclusionsResults suggest that immune-mediated tryptophan degradation may contribute to cancer-induced QoL deterioration.