Abstract
INTRODUCTION: 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. CONCLUSION: Increased circulating CRP and IL-6 levels were significantly associated with poor prognosis especially in patients with unresectable NSCLC.