title: Association between an elevated level of HMGB1 and non-small-cell lung cancer: a meta-analysis and literature review.
abstract: BACKGROUND
  HMGB1 has been overexpressed in the tissues or serum of patients with non-small-cell lung cancer (NSCLC) in several studies. However, the results remain inconsistent.
  
  
  OBJECTIVE
  The aim of this study was to perform a meta-analysis to investigate the relationship between elevated level of HMGB1 and NSCLC.
  
  
  METHODS
  Associated studies were included, and the pooled risk difference and mean difference (MD) together with 95% confidence interval (CI) were calculated.
  
  
  RESULTS
  A total of ten relevant studies on HMGB1 expression were included in this meta-analysis. The pooled results suggested that the expression of HMGB1 in NSCLC tissues was notably higher than those in corresponding nontumor normal tissues by using immu-nohistochemistry (risk difference =0.38, 95% CI: 0.28-0.48, Z=7.67, P<0.00001, I (2)=0%), Western blot (MD =0.27, 95% CI: 0.06-0.47, Z=2.57, P<0.01), or real-time polymerase chain reaction (MD =15.15, 95% CI: 14.8-15.5, Z=2.08, P=0.04). Serum HMGB1 levels were similarly significantly higher in patients with NSCLC than those in healthy controls. The pooled MDs of HMGB1 in patients with NSCLC compared with healthy controls were 17.54 with 95% CI: 10.99-24.09, Z=5.25, P<0.00001. Two of the included studies were fully reviewed without performing meta-analysis due to the different detection methods used. The protein level of HMGB1 in patients with NSCLC of tumor, nodes, and metastasis (TNM) stages III-IV was higher than that of TNM stages I-II (P<0.047 and P<0.001, respectively).
  
  
  CONCLUSIONS
  The expression levels of HMGB1 in both tissues and serum of patients with NSCLC were statistically higher than those of normal lung samples, which indicated that elevated levels of HMGB1 can reveal changes that correlated with disease progression, or even the risk of NSCLC disease progression. The elevated level of HMGB1 could also be considered as a potential biomarker for the diagnosis of patients with NSCLC.
authors.affiliation: Clinical Laboratory, The Third Affiliated Hospital of Kunming Medical University.
authors.forename: Quansong
authors.initials: Q
authors.lastname: Xia
authors.affiliation: The People's Hospital of Guandu District, Kunming.
authors.forename: Juan
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Immunology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Huoying
authors.initials: H
authors.lastname: Chen
authors.affiliation: Clinical Laboratory, The Third Affiliated Hospital of Kunming Medical University.
authors.forename: Yanzhang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Immunology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Feili
authors.initials: F
authors.lastname: Gong
authors.affiliation: Clinical Laboratory, The Third Affiliated Hospital of Kunming Medical University.
authors.forename: Liya
authors.initials: L
authors.lastname: Hu
authors.affiliation: Clinical Laboratory, The Third Affiliated Hospital of Kunming Medical University.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
keywords: HMGB1; meta-analysis; non-small-cell lung cancer