C-reactive protein is a predictor of prognosis in renal cell carcinoma patients receiving tyrosine kinase inhibitors: A meta-analysis

Background The prognostic value of C-reactive protein (CRP) in metastatic renal cell carcinoma (RCC) patients receiving tyrosine kinase inhibitors (TKIs) has been investigated in previous studies; however, the results remain inconclusive. This study investigated the prognostic value of pretreatment CRP in patients with metastatic RCC treated with TKIs. Methods: PubMed, Embase, Web of Science, and Cochrane databases were searched for studies investigating the relationships between pretreatment CRP and prognosis in patients with metastatic RCC. Hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) were extracted from eligible studies. Heterogeneity was assessed using the I-2 value. The fixed-effects model was used if there was no evidence of heterogeneity; otherwise, the random-effects model was used. Publication bias was evaluated using Begg's funnel plots and Egger's regression test. Results: A total of 1199 patients from nine studies were included in the analysis. The results showed that an elevated CRP level was an effective prognostic marker of both OS (pooled HR = 2.87, 95% confidence interval [CI]: 2.34-3.54, p < 0.001) and PFS (pooled HR = 2.39, 95% CI: 1.75-3.26, p < 0.001). Subgroup analysis revealed that an elevated CRP level significantly predicted poor OS and PFS in studies conducted in Japan (OS, pooled HR = 3.03, 95% CI: 2.29-4.01, p < 0.001; PFS, pooled HR = 3.6, 95% CI: 1.62-8.0, p = 0.002), and in cut-off value of CRP < 0.8 (OS, pooled HR = 2.93, 95% CI: 2.21-3.88, p < 0.001; PFS, pooled HR = 2.57, 95% CI: 1.82-3.65, p < 0.001). Conclusions: This study suggests that an elevated CRP level is correlated with poor prognosis in patients with metastatic RCC receiving TKIs treatment.