Prognostic significance of regulatory T lymphocytes in patients with hepatocellular carcinoma.

We investigated the prognostic role of regulatory T cells (Tregs) in patients with hepatocellular carcinoma (HCC). Relevant evidence regarding prognostic significance of Tregs was systematically searched in MEDLINE and Embase databases. A meta-analysis was performed to compare survival in patients with high or low Tregs level (either in peripheral blood or tumor). Eighteen studies were identified that fulfilled for the eligibility criteria and were included for data synthesis. Our pooled hazard ratios (HRs) demonstrated that increased Tregs intratumoral accumulation was significantly associated with worse overall survival (HR=2.04, 95% confidence interval (CI): 1.72-2.42) and disease-free survival (HR=1.82, 95% CI: 1.58-2.09). Three studies evaluated the role of Tregs in peripheral blood, and all of them showed that increased peripheral Tregs correlated with shortened disease-free and overall survival. Collectively, our results showed that the increased Tregs count is tightly associated with the shortened survivals. Its measurement in either primary tumor or even circulation might be a candidate marker of prognostic significance in HCC patients.