title: Prognostic value of circulating inflammatory factors in non-small cell lung cancer: a systematic review and meta-analysis.
abstract: BACKGROUND
  Inflammation has been recognized as an important contributing factor in the development and progression of lung cancer. However, the relationship between the magnitude of inflammation and prognosis in patients with lung cancer remains unclear. This meta-analysis aimed to investigate the association between levels of circulating inflammatory factors and clinical survival in patients with non-small cell lung cancer(NSCLC).
  
  
  METHODS
  We conducted a meta-analysis of cohort studies to evaluate the prognostic effect of circulating inflammatory factors. Twenty-three studies were eligible and included in our meta-analysis. The pooled hazard ratios (HRs) and their 95% confidence intervals (CIs) were used to assess the predictive ability of circulating inflammatory factors on overall survival (OS) in patients with NSCLC.
  
  
  RESULTS
  In overall analysis, high circulating C-reactive protein (CRP) and interleukin-6 (IL-6) level were significantly associated with shorter OS in NSCLC. However, either in CRP or IL-6 subgroup analysis by treatment, significant association with poor prognosis was observed in (radio)chemotherapy group (HR[95% CI]:1.30 [1.09-1.54] and 1.80 [1.32-2.46]; respectively), but not in surgery group. Additionally, there was no significant association between circulating IL-8, IL-10, TNF-α level and OS.
  
  
  CONCLUSIONS
  Increased circulating CRP and IL-6 levels were significantly associated with poor prognosis especially in patients with unresectable NSCLC.
authors.affiliation: Department of Respiratory Disease, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Liao
authors.affiliation: Department of Thoracic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Zubin
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Department of Systems Biology, UT MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.affiliation: Department of Epidemiology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Qingyun
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Epidemiology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Epidemiology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Respiratory Disease, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Bai
mesh_terms: D014408:Biomarkers, Tumor; D002097:C-Reactive Protein / Q000235:genetics*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D016209:Interleukin-8 / Q000235:genetics; D009360:Neoplastic Cells, Circulating / Q000473:pathology; D011379:Prognosis; D016019:Survival Analysis; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein
keywords: C-reactive protein; Non-small cell lung cancer; circulating inflammatory factor; interleukin-6; prognosis