title: Altered plasma levels of decanoic acid in colorectal cancer as a new diagnostic biomarker.
abstract: Colorectal cancer (CRC) is one of the most common tumors in developed countries. The five-year survival rate decreases depending on how advanced the CRC is when first diagnosed. Screening has been proven to greatly reduce mortality from colorectal cancer, but an ideal screening tool is far from being established. Here, we aimed to discover and validate early CRC biomarkers by means of an untargeted/targeted metabolomic approach. A preliminary untargeted analysis of plasma lipids performed on a small patient cohort (30 plasma samples) revealed some alterations that occurred in the presence of this tumor. In particular, medium-chain fatty acids with between six and twelve carbon atoms (C6-C12) were found to be the lipid class that showed the most marked changes upon the development of CRC. In order to evaluate the utility of this lipid class as diagnostic CRC biomarkers, a further study based on a wider cohort of patients (117 plasma samples) was performed. Using a targeted approach, these fatty acids were quantified in plasma samples by means of fast gas chromatography coupled to a time-of-flight analyzer. Plasma samples from patients with CRCs at different tumor stages were analyzed and compared to those from healthy subjects, ulcerative colitis patients, high-grade dysplasia adenoma patients, and breast cancer patients in order to test the specificity and sensitivity of these possible biomarkers. Results revealed significant differences among the considered groups in terms of their C6, C8, C10, and C12 fatty acid plasma concentrations. In particular, receiver operating characteristic (ROC) curves obtained for the C10 fatty acid gave an area under the curve of 0.8195 along with a sensitivity of 87.8 % and a specificity of 80 %, strongly suggesting that it could be a valuable early diagnostic biomarker of CRC.
authors.affiliation: Nano-inspired Biomedicine Laboratory, Institute of Paediatric Research-Città della Speranza, Corso Stati Uniti 4, 35127, Padova, Italy. s.crotti@irpcds.org.
authors.forename: Sara
authors.initials: S
authors.lastname: Crotti
authors.affiliation: Department of Chemical Sciences, University of Padua, via Marzolo 1, 35131, Padova, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Agnoletto
authors.affiliation: Nano-inspired Biomedicine Laboratory, Institute of Paediatric Research-Città della Speranza, Corso Stati Uniti 4, 35127, Padova, Italy.|CNR-IENI, Corso Stati Uniti 4, 35127, Padova, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Cancemi
authors.affiliation: Department of Chemical Sciences, University of Padua, via Marzolo 1, 35131, Padova, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Di Marco
authors.affiliation: Nano-inspired Biomedicine Laboratory, Institute of Paediatric Research-Città della Speranza, Corso Stati Uniti 4, 35127, Padova, Italy.|CNR-IENI, Corso Stati Uniti 4, 35127, Padova, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Traldi
authors.affiliation: First Surgical Clinic Section, Department of Surgical, Oncological and Gastroenterological Sciences, University of Padua, via Nicolò Giustiniani 2, 35128, Padova, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Pucciarelli
authors.affiliation: First Surgical Clinic Section, Department of Surgical, Oncological and Gastroenterological Sciences, University of Padua, via Nicolò Giustiniani 2, 35128, Padova, Italy.
authors.forename: Donato
authors.initials: D
authors.lastname: Nitti
authors.affiliation: Nano-inspired Biomedicine Laboratory, Institute of Paediatric Research-Città della Speranza, Corso Stati Uniti 4, 35127, Padova, Italy.|First Surgical Clinic Section, Department of Surgical, Oncological and Gastroenterological Sciences, University of Padua, via Nicolò Giustiniani 2, 35128, Padova, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Agostini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000097:blood* / Q000175:diagnosis; D003652:Decanoic Acids / Q000097:blood*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged
chemical_list: D014408:Biomarkers, Tumor; D003652:Decanoic Acids; C031071:decanoic acid
keywords: Biomarkers; Colorectal cancer; Free fatty acids; GC-MS