title: Plasma Tumor M2-Pyruvate Kinase Levels in Different Cancer Types.
abstract: OBJECTIVE
  Tumor M2-pyruvate kinase (M2-PK) is up-regulated in proliferating tissues. It has been shown that tumor M2-PK is detectable and quantifiable in the stool and plasma of patients with colorectal cancer (CRC). Tumor M2-PK has been extensively studied in gastrointestinal tumors but its role in other cancer types has not yet been deeply evaluated. The aim of the study was to determine and compare plasma tumor M2-PK levels in different cancer types.
  
  
  METHODS
  All patients undergoing diagnostics for cancer at our Hospital during 2011 were included in the study (n=139). Plasma tumor M2-PK concentration was analyzed by an enzyme-linked immunosorbent assay.
  
  
  RESULTS
  The different cancer types found in the study were: 60 colorectal, 43 breast, 8 lung, 5 prostatic, 4 ovarian and the remaining 19 cases were other uncommon tumor types. Most tumors had high concentrations of tumor M2-PK; prostatic, pharyngeal and testicular tumors had levels lower than or near the cut-off. Plasma tumor M2-PK levels were significantly higher in patients with distant metastases and stage IV by TNM.
  
  
  CONCLUSIONS
  Plasma tumor M2-PK is not a specific marker for CRC and is elevated in many other types of cancers, including breast, lung, ovarian, and thyroid. Small amounts are found in prostatic, pharyngeal and testicular tumors.
authors.affiliation: Laboratory of Clinical Analysis, Alta Resolución Sierra de Segura Hospital, Puente de Génave, Jaén, Spain aurora_mc82@hotmail.com.
authors.forename: Aurora
authors.initials: A
authors.lastname: Muñoz-Colmenero
authors.affiliation: Department of Biotechnology, Alto Guadalquivir Hospital, Andújar, Jaén, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Fernández-Suárez
authors.affiliation: Department of Biotechnology, Alto Guadalquivir Hospital, Andújar, Jaén, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Fatela-Cantillo
authors.affiliation: Laboratory of immunology, Ciudad de Jaén Hospital, Jaén, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Ocaña-Pérez
authors.affiliation: Department of Gastroenterology, Alto Guadalquivir Hospital, Andújar, Jaén, Spain.
authors.forename: José L
authors.initials: JL
authors.lastname: Domínguez-Jiménez
authors.affiliation: Department of Pathology, Alto Guadalquivir Hospital, Andújar, Jaén, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Díaz-Iglesias
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood*; D011770:Pyruvate Kinase / Q000097:blood*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D011770:Pyruvate Kinase
keywords: Tumor M2-pyruvate kinase; cancer type; distant metastases; nodal metastases; tumor size; tumor stage