The prognostic value of proliferating cell nuclear antigen expression in colorectal cancer: A meta-analysis

BACKGROUND: A number of studies have attempted to determine the prognostic significance of proliferating cell nuclear antigen (PCNA) in patients with colorectal cancer (CRC), but the reports are controversial and inconsistent. Thus, we conducted a meta-analysis to clarify the value of PCNA in CRC prognosis. METHODS: A systematic search of relevant studies was performed in 4 electronic databases including PubMed, Cochrane Library, Embase, and Web of Science until February 2018. Hazard ratios (HRs) combined with 95% confidence intervals (95% CIs) were used to evaluate the relationship of PCNA expression with overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). RESULTS: A total of 1372 CRC patients in 14 studies were identified eventually in our meta-analysis. The pooled HRs demonstrated that CRC patients with high PCNA expression was significantly correlated with poor OS (HR = 1.81; 95% CI: 1.51–2.17; P = .000), CSS (HR = 1.99; 95% CI: 1.04–3.79; P = .037); but not significantly with DFS (HR = 2.48; 95% CI: 0.98–6.26; P = .055). Sensitivity analysis showed the pooled HRs for OS, CSS, and DFS were stable when the included studies were removed one by one. CONCLUSION: Our meta-analysis suggested that high PCNA expression was associated with poor prognosis, and it could serve as a reliable and prognostic biomarker in CRC patients. More large-scale studies are needed to further support the conclusion.