title: Plasma lysophosphatidylcholine levels: potential biomarkers for colorectal cancer.
abstract: OBJECTIVE
  Plasma levels of lysophospholipids were evaluated as potential biomarkers for colorectal cancer (CRC), where a highly reliable and minimally invasive blood test is lacking.
  
  
  METHODS
  Patients with CRC (n = 133) and control subjects (n = 125) were recruited through the Cleveland Clinic. Preoperative plasma samples were analyzed for lysophospholipid levels using liquid chromatography mass spectrometry in a blinded fashion. Participants were randomly divided in a 2:1 ratio into a "training set" (TS) and a "validation set" (VS). Logistic regression models were used in the TS to identify markers that best discriminated between CRC and controls. A cutoff point for the final discriminating model was developed using the receiver operating characteristic curve to achieve 95% specificity. All analyses were then independently validated in the VS.
  
  
  RESULTS
  Plasma levels of several lysophosphatidylcholines (LPCs), including 18:1- and 18:2-LPC, were significantly decreased in CRC patients compared with controls (P < .001). A model based on total saturated LPC and the difference between the proportional amounts of 18:2-LPC and 18:1-LPC in the unsaturated LPC fraction was derived from the TS. This model achieved a sensitivity and specificity of 82% and 93%, respectively, in the VS. Overall, 118 (94%) of 125 control subjects and 113 (85%) of 133 CRC cases were correctly identified, including eight (89%) of nine CRC cases with stage T1 disease.
  
  
  CONCLUSIONS
  Percentage of 18:1-LPC or 18:2-LPC plasma levels compared with total saturated LPC levels, either individually or in combination, may represent potential biomarkers for CRC.
authors.affiliation: Department of Cancer Biology, Lerner Research Institute, Taussig Cancer Center, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Zhenwen
authors.initials: Z
authors.lastname: Zhao
authors.forename: Yijin
authors.initials: Y
authors.lastname: Xiao
authors.forename: Paul
authors.initials: P
authors.lastname: Elson
authors.forename: Haiyan
authors.initials: H
authors.lastname: Tan
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Plummer
authors.forename: Michael
authors.initials: M
authors.lastname: Berk
authors.forename: Phyu P
authors.initials: PP
authors.lastname: Aung
authors.forename: Ian C
authors.initials: IC
authors.lastname: Lavery
authors.forename: Jean P
authors.initials: JP
authors.lastname: Achkar
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Graham
authors.initials: G
authors.lastname: Casey
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D002853:Chromatography, Liquid / Q000379:methods; D015179:Colorectal Neoplasms / Q000097:blood* / Q000175:diagnosis; D005260:Female; D006801:Humans; D008244:Lysophosphatidylcholines / Q000097:blood*; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D008875:Middle Aged; D015999:Multivariate Analysis; D012372:ROC Curve; D012044:Regression Analysis; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D008244:Lysophosphatidylcholines