title: Serum metabolomics as a novel diagnostic approach for gastrointestinal cancer.
abstract: Conventional tumor markers are unsuitable for detecting carcinoma at an early stage and lack clinical efficacy and utility. In this study, we attempted to investigate the differences in serum metabolite profiles of gastrointestinal cancers and healthy volunteers using a metabolomic approach and searched for sensitive and specific metabolomic biomarker candidates. Human serum samples were obtained esophageal (n = 15), gastric (n = 11), and colorectal (n = 12) cancer patients and healthy volunteers (n = 12). A model for evaluating metabolomic biomarker candidates was constructed using multiple classification analysis, and the results were assessed with receiver operating characteristic curves. Among the 58 metabolites, the levels of nine, five and 12 metabolites were significantly changed in the esophageal, gastric and colorectal cancer patients, respectively, compared with the healthy volunteers. Multiple classification analysis revealed that the variations in the levels of malonic acid and L-serine largely contributed to the separation of esophageal cancer; gastric cancer was characterized by changes in the levels of 3-hydroxypropionic acid and pyruvic acid; and L-alanine, glucuronoic lactone and L-glutamine contributed to the separation of colorectal cancer. Our approach revealed that some metabolites are more sensitive for detecting gastrointestinal cancer than conventional biomarkers. Our study supports the potential of metabolomics as an early diagnostic tool for cancer.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-Cho, Chu-o-ku, Kobe, Hyogo 650-0017, Japan.
authors.forename: Atsuki
authors.initials: A
authors.lastname: Ikeda
authors.forename: Shin
authors.initials: S
authors.lastname: Nishiumi
authors.forename: Masakazu
authors.initials: M
authors.lastname: Shinohara
authors.forename: Tomoo
authors.initials: T
authors.lastname: Yoshie
authors.forename: Naoya
authors.initials: N
authors.lastname: Hatano
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Okuno
authors.forename: Takeshi
authors.initials: T
authors.lastname: Bamba
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Fukusaki
authors.forename: Tadaomi
authors.initials: T
authors.lastname: Takenawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Azuma
authors.forename: Masaru
authors.initials: M
authors.lastname: Yoshida
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D005770:Gastrointestinal Neoplasms / Q000097:blood* / Q000175:diagnosis; D006801:Humans; D008297:Male; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D008875:Middle Aged; D025341:Principal Component Analysis; D012372:ROC Curve
chemical_list: D014408:Biomarkers, Tumor