title: A systematic review and meta-analysis of the diagnostic accuracy of pyruvate kinase M2 isoenzymatic assay in diagnosing colorectal cancer.
abstract: BACKGROUND
  Screening programmes exist in many countries for colorectal cancer. In recent years, there has been a drive for a non-invasive screening marker of higher sensitivity and specificity. Stool-based pyruvate kinase isoenzyme M2 (M2-PK) is one such biomarker under investigation. The aim of this systematic review and meta-analysis is to determine the diagnostic accuracy, sensitivity and specificity of M2-PK as a screening tool in colorectal cancer.
  
  
  METHODS
  A literature search of Ovid Medline, EMBASE and Google Scholar was carried out. The search strategy was restricted to human subjects and studies published in English. Data on sensitivity and specificity were extracted and pooled. Statistical analysis was conducted using summary receiver operating characteristic (SROC) curve methodology.
  
  
  RESULTS
  A total of eight studies were suitable for data synthesis and analysis. Our analysis showed a pooled sensitivity and specificity for M2-PK to be 79% (CI 73%-83%) and 80% (CI 73%-86%), respectively. The accuracy of M2-PK was 0.85(0.82-0.88).
  
  
  CONCLUSIONS
  Faecal M2-PK assay has a relatively good sensitivity and specificity and high accuracy for screening colorectal cancer.
authors.affiliation: Surgical Epidemiology, Trials and Outcome Centre (SETOC), St Mark's Hospital and Academic Institute, Harrow, Middlesex, HA1 3UJ, UK. drmallikarjuna@gmail.com.
authors.forename: Mallikarjuna
authors.initials: M
authors.lastname: Uppara
authors.affiliation: Department of Surgery, St Mark's Hospital and Academic Institute, Harrow, Middlesex, HA1 3UJ, UK. uchiecoche@yahoo.co.uk.
authors.forename: Franklin
authors.initials: F
authors.lastname: Adaba
authors.affiliation: Surgical Epidemiology, Trials and Outcome Centre (SETOC), St Mark's Hospital and Academic Institute, Harrow, Middlesex, HA1 3UJ, UK. alan.askari@gmail.com.
authors.forename: Alan
authors.initials: A
authors.lastname: Askari
authors.affiliation: Department of Surgery, St Mark's Hospital and Academic Institute, Harrow, Middlesex, HA1 3UJ, UK. s.clark8@nhs.net.|North West London Hospitals Trust, Harrow, Middlesex, HA1 3UJ, UK. s.clark8@nhs.net.
authors.forename: Susan
authors.initials: S
authors.lastname: Clark
authors.affiliation: Department of Surgical Sciences, Imperial College, St Mary's Hospital, Praed Street, London, W21NY, UK. g.hanna@imperial.ac.uk.
authors.forename: George
authors.initials: G
authors.lastname: Hanna
authors.affiliation: Department of Cardiovascular Sciences and Cardiac Surgery, Imperial College, St Mary's Hospital, Praed Street, London, W21NY, UK. t.athanasiou@imperial.ac.uk.
authors.forename: Thanos
authors.initials: T
authors.lastname: Athanasiou
authors.affiliation: Surgical Epidemiology, Trials and Outcome Centre (SETOC), St Mark's Hospital and Academic Institute, Harrow, Middlesex, HA1 3UJ, UK. o.faiz@imperial.ac.uk.
authors.forename: Omar
authors.initials: O
authors.lastname: Faiz
mesh_terms: D001681:Biological Assay; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000201:enzymology*; D055088:Early Detection of Cancer; D006801:Humans; D011379:Prognosis; D011770:Pyruvate Kinase / Q000032:analysis*
chemical_list: D011770:Pyruvate Kinase