Association Between Baseline C-reactive Protein Level And Survival Outcomes For Cancer Patients Treated With Immunotherapy:A Meta-analysis

Objective: Immune checkpoint inhibitors(ICIs)have been increasingly applied in the treatment of several kinds of malignant tumors.The present meta-analysis aimed to evaluate the prognostic value of baseline C-reactive protein(CRP)level for cancer patients receiving immunotherapy.Methods: The electronic databases,including CNKI,Wanfang,VIP,Pubmed and Embase databases,were systemically searched to identify relevant studies.According to the study inclusion and exclusion criteria,relevant cohort studies reporting the baseline CRP level and ICIs survival outcomes were selected.Thereafter,data were extracted and the study quality was evaluated.Meta-analysis was conducted using the STATA 14.0 software;then,the pooled hazard ratio(HR)and corresponding 95% confidence interval(CI)for overall survival(OS)and progression-free survival(PFS)were calculated using the random-effects or fixed-effects models.Further,subgroup analysis,sensitivity analysis,and publication bias assessment were conducted to examine the relationship between baseline CRP level and survival outcomes of patients treated with ICIs.Results: A total of 13 eligible studies comprising 2387 cancer patients treated with ICIs were included for final analysis.According to the pooled analysis results,the elevated baseline CRP level was significantly associated with poor OS and PFS among patients treated with ICIs(OS: HR=1.62,95%CI: 1.27-2.07,P=0.000;PFS: HR=1.54,95%CI: 1.28-1.84,P=0.000).As suggested by subgroup analysis stratified by cancer type,the elevated baseline CRP level was associated with poor survival outcomes of multiple cancer types.Similar results were observed in subgroup analysis stratified by the CRP cut-off value of 10 mg/L.Besides,a higher mortality risk was reported in cancer patients with CRP≥10 mg/L(HR=2.76,95%CI: 1.70-4.48,P=0.000).Conclusion: Compared with patients with low baseline CRP level,the elevated baseline CRP level was associated with poor OS and PFS in cancer patients receiving ICIs.Furthermore,CRP≥10 mg/L indicated the worse prognosis.Therefore,baseline CRP level might serve as one of the markers for the prognosis of patients with certain solid tumor treated with ICIs.