title: The prognostic value of lactate dehydrogenase levels in colorectal cancer: a meta-analysis.
abstract: BACKGROUND
  The prognostic value of lactate dehydrogenase levels in the prognosis of colorectal cancer patients has been assessed for years, although the results remain controversial and heterogeneous. Thus, we comprehensively reviewed the evidence from studies that evaluated lactate dehydrogenase levels in colorectal cancer patients to determine their effect.
  
  
  METHODS
  The following databases were searched in September 2014 to identify studies that evaluated the prognostic value of lactate dehydrogenase levels in colorectal cancer: PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials. We extracted hazard ratios (HRs) and the associated 95% confidence intervals (CIs) from the identified studies, and performed random-effects model meta-analyses on the overall survival (OS) and progression-free survival (PFS). Thirty-two studies with a cumulative sample size of 8,261 patients were included in our analysis.
  
  
  RESULTS
  Our meta-analyses revealed that high levels of lactate dehydrogenase were associated with poor OS (HR, 1.75; 95% CI, 1.52-2.02) in colorectal cancer patients. However, this effect was not obvious in the OS of non-metastatic colorectal cancer patients (HR, 1.21; 95% CI, 0.79-1.86). The prognostic value of lactate dehydrogenase levels on PFS was also not confirmed (HR, 1.36; 95% CI, 0.98-1.87). Subgroup analyses revealed that the prognostic significance of lactate dehydrogenase was independent of study location, patient age, number of patients, metastasis, chemotherapy with anti-angiogenesis drugs, study type, or risk of bias.
  
  
  CONCLUSIONS
  Our results indicate that high lactate dehydrogenase levels are associated with poor OS among colorectal cancer patients, although these levels are not significant predictors of PFS.
authors.affiliation: Department of Gastrointestinal Surgery, First Affiliated Hospital of Sun Yat-sen University, 510080, Guangzhou, Guangdong Province, People's Republic of China.
authors.forename: Guanghua
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Gastrointestinal Surgery, First Affiliated Hospital of Sun Yat-sen University, 510080, Guangzhou, Guangdong Province, People's Republic of China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Gastrointestinal Surgery, First Affiliated Hospital of Sun Yat-sen University, 510080, Guangzhou, Guangdong Province, People's Republic of China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Gastrointestinal Surgery, First Affiliated Hospital of Sun Yat-sen University, 510080, Guangzhou, Guangdong Province, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Gastrointestinal Surgery, First Affiliated Hospital of Sun Yat-sen University, 510080, Guangzhou, Guangdong Province, People's Republic of China.
authors.forename: Shirong
authors.initials: S
authors.lastname: Cai
authors.affiliation: Department of Gastrointestinal Surgery, First Affiliated Hospital of Sun Yat-sen University, 510080, Guangzhou, Guangdong Province, People's Republic of China. lgh8711@126.com.
authors.forename: Yulong
authors.initials: Y
authors.lastname: He
mesh_terms: D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D015179:Colorectal Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D018572:Disease-Free Survival; D006801:Humans; D045022:Lactate Dehydrogenases / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models
chemical_list: D020533:Angiogenesis Inhibitors; D045022:Lactate Dehydrogenases
keywords: Colorectal cancer; Lactate dehydrogenase; Meta-analysis; Prognosis