Complement Component 3 (C3) Concentrations in Cancer Patients: A Systematic Review and Meta-Analysis

Abstract

BackgroundThe aim of this study was to investigate the association between the serum complement component 3 "C3" level and the patients with different types of cancer. Our study finding would ultimately provide reliable scientific conclusions to guide clinical practice. MethodsPubMed, Embase, The Chorane Library and Google Scholar were systematically searched to identify all studies on serum C3 concentrations in cancer patients published as of September 2019.Additionally, we conducted a clinical study on serum C3 in lung cancer patients and healthy people.The levels of serum complement C3 in 84 lung cancer patients and 30 healthy people were examined by ELISA. We used standardized mean differences (SMD) to report the pooled estimation, and I² statistics were calculated to examine the heterogeneity. For pooling estimates, a fixed effect metaanalysis was conducted on our studies. Two independent reviewers extracted relevant data and conducted deviation risk assessment. Our Meta-analysis was performed using STATA software and Review Manager 5.3. ResultsThe C3 levels of 83 lung cancer patients were 1.07 ± 0.34, and 30 healthy people were 0.95 ± 0.17 (the unit is g/l, keep two decimal places after the decimal point), and the p-value for t-test was 0.014 (<0.05). The overall C3 concentrations of cancer patients were significantly higher than the healthy control (SMD:0.30, 95%CI = 0.20 to 0.40 , p-value <0.00001). There was a certain degree of heterogeneity in the article, but it was acceptable (χ² = 31.89, p-value = 0.02, I²= 44%). ConclusionsConcentration analysis and this meta-analysis revealed that the serum C3 concentrations in cancer patients are significantly higher than that of healthy people. Further well-designed, large-scale, randomized controlled trials are needed to confirm this conclusion.