Background: This study was carried out to determine the prognostic significance of preoperative peripheral epithelial cell adhesion molecule- positive (EpCAM (+)) circulating tumor cell (CTC) and T regulatory (Treg) cell levels in hepatocellular carcinoma (HCC) patients for the prediction of postoperative recurrence following curative resection.
Methods: A total of 49 patients about to undergo curative resection for HCC were recruited into the study. PCR and FACS were used to detect the preoperative levels of EpCAM (mRNA+) CTCs and CD4(+)CD25(+)Foxp3(+) Treg cells. The prognostic value of EpCAM (mRNA+) CTCs, CD4(+)CD25(+)Foxp3(+) Treg cells, and other clinicopathological factors were analyzed by applying the Kaplan-Meier method and the multivariate Cox proportional hazards model.
Results: The number of EpCAM (mRNA+) CTCs and Treg/CD4(+) cells showed significant correlation as prognostic factors of postoperative HCC recurrence: EpCAM (mRNA+) CTC ≥ 2.22 (P = 0.001) and Treg/CD4(+) ≥ 5.07 (P = 0.045), with EpCAM (mRNA+) CTC ≥ 2.22 (P = 0.003, HR = 6.668) being the most important indicator. Patients with high CTC/Treg levels showed a significantly higher risk of developing postoperative HCC recurrence than those with low CTC/Treg levels (66.7 % vs. 10.3 %, P < 0.001). The high CTC/low Treg group also presented higher 1-year recurrence rates compared with the low CTC/low Treg level group (50.0 % vs. 10.3 %, P = 0.004).
Conclusions: Elevated EpCAM (mRNA+) CTC and Treg/CD4(+) levels were associated with early recurrence of HCC, indicative of poor clinical outcome. The combined detection of EpCAM (mRNA+) CTC and Treg/CD4(+) may therefore provide a novel prognostic predictor for HCC patients.
Keywords: Circulating tumor cells; Epithelial cell adhesion molecule; Hepatocellular carcinoma; Regulatory T cells; Tumor recurrence.