Serum metabonomics as a diagnostic approach for cancer-related fatigue

In the present study, differences in metabolic pathways between patients with and without cancer-related fatigue (CRF) were examined to identify metabolic serum biomarkers of CRF. In this preliminary study, metabolic profiling was applied to analyze the serum samples from 14 patients with CRF and 11 non-CRF individuals (non-fatigue cancer survivors) by ultra-performance liquid chromatography coupled with mass spectrometry. Orthogonal partial least-squares discriminant analysis was adopted to evaluate the differences between the CRF and non-CRF groups. The CRF group was characterized by increases in phosphatidylethanolamine (PE; 18:0/0:0), LysoPE (0:0/20:4 and 0:0/16:0), lysophosphatidylcholine (LysoPC; 20:4, 22:4 and 16:0) and LysoPC/PC, phosphatidylserine (21:0/0:0), glycerophosphocholine and N-docosahexaenoyl gamma-aminobutyric acid. Furthermore, decreases in anandamide, uric acid, dihydrouracil, LysoPE (0:0/22:5), 2,5,7,8-tetramethyl-2(2'-carboxyethyl)-6-hydroxychroman, 19(R)-hydroxy-prostaglandin F1 alpha, N-(3 alpha,12 alpha-dihydroxy-5 beta-cholan-24-oyl)-glycine, ketoleucine, indoxyl sulfate, alpha-N-phenylacetyl-L-glutamine and 1-linoleoyl-glycerophosphocholine were detected. These data indicate a possible disturbance in the metabolism of phospholipids and adjustments in the endocannabinoid system. The metabonomic approach may be helpful to determine the pathophysiological mechanisms of CRF and the identification of potential biomarkers for the accurate diagnosis of CRF. All clinical data were obtained from the 'Research on the efficacy of traditional Chinese medicine comprehensive intervention in cancer-related fatigue' (TCM-CRF) project. Medical Ethical Approval for TCM-CRF was approved by the Chinese Ethics Committee of Registering Clinical Trials. The approval number for the TCM-CRF study was ChiECRCT-2013038, and the TCM-CRF study was completed.