Prognostic role of C-reactive protein in breast cancer: A systematic review and meta-analysis

Background: Recent studies have shown that C-reactive protein (CRP) may be associated with breast cancer. The purpose of this study is to summarize the predictive role of CRP for survival in breast cancer as shown in all available studies worldwide. Methods: Related studies were identified and evaluated for quality through multiple search strategies. Data were collected from studies comparing overall, cancer-specific, and disease-free survival (OS, CSS, and DFS) in patients with elevated CRP levels and those having lower levels. Studies were pooled, and combined hazard ratios (HRs) of CRP for survival were calculated. Results: A total of 10 studies (n=4,502) were included for this meta-analysis (9 for OS, 3 for CSS, and 3 for DFS). For overall and disease-free survival, the pooled HRs of CRP were significant at 1.62 (95% confidence interval [95% CI], 1.20-2.18) and 1.81 (95% CI, 1.44-2.26), respectively. For cancer-specific survival, the pooled HR in higher CRP expression in breast cancer was 2.08 (95% CI, 1.48-2.94), which could strongly predict poorer survival in breast cancer. Conclusions: CRP has a critical prognostic value in patients with breast cancer as an inflammation biomarker.