Detection of PD-L1⁽⁺⁾Circulating Tumor Cells Significantly Correlates with Postoperative Recurrence in HCC Patients

Background/Purpose Hepatocellular carcinoma (HCC) is the fifth most common tumor worldwide. Circulating tumor cells (CTCs) are associated with an increased risk of recurrence. Programmed death ligand 1 (PD-L1) is associated with increased tumor aggressiveness. The aim of this work is to evaluate the potential of CTCs with PD-L1 expression (PD-L1⁽⁺⁾CTCs) as prognostic markers in HCC.

Methods Blood samples from 28 patients with HCC who underwent tumor resection were analyzed. Venous blood was taken before and immediately after the surgery to isolate and quantify PD-L1⁽⁺⁾CTCs by flow cytometry. Hepatitis and HIV infection were an exclusion criterion in this study.

Results Twelve HCC patients (42.8 %) had liver cirrhosis. The median overall survival was 27.3 months. The median recurrence-free survival was 15.8 months. PD-L1⁽⁺⁾CTCs (21.4 %, 0.5 PD-L1⁽⁺⁾CTC/ml) could be identified in 6 patients after the surgery. The postoperative detection of PD-L1⁽⁺⁾CTCs correlated with tumor aggressiveness and shorter recurrence-free survival (p = 0.002) as well as with shorter overall survival (p = 0.050).

Conclusion The postoperative detection of PD-L1⁽⁺⁾CTCs correlates with tumor aggressiveness and postoperative recurrence in human hepatocellular carcinoma. The adjuvant administration of checkpoint inhibitors in HCC patients with positive PD-L1⁽⁺⁾CTCs could represent an interesting approach for clinical studies.

Publication History

Article published online:
04 January 2021