PD1 and TIM3 Expression is Associated with Very Early Hepatocellular Carcinoma Recurrence After Percutaneous Thermal Ablation

Abstract

Purpose: Percutaneous thermal ablation (PTA) is a cornerstone in the management of early-stage hepatocellular carcinoma (HCC). However, intrahepatic distant recurrence (IDR) occurs in the majority of patients after PTA. The aim of this study was to evaluate the immune signature associated with very early IDR.

Patients and methods: Thirty-one patients (26 men, 5 women; mean age:72.4 ± 8.6; age range:57-86 years) who underwent PTA for HCC were included in this study. After PTA for HCC, patients were followed and later divided into two groups: a "very early recurrence" group in case of IDR within 12 months after PTA, and a "prolonged recurrence-free" group in case of no recurrence before 12 months of follow-up. Freshly harvested intratumoral and nontumoral liver tissues and peripheral blood were obtained before PTA and explored by multiparametric flow cytometry.

Results: The frequency of PD1⁺CD4⁺ T cells was higher in the early recurrence group than in the prolonged recurrence-free group in the peripheral blood (24.3%, IQR: 22.3-36.5 vs 14.0%, IQR: 11.5-16.4, p<0.0001), in the nontumoral liver (37.9%, IQR: 36.0-50.0 vs 22.5%, IQR: 18.0-29.9, p=0.0004), and in the tumor (37.6%, IQR: 32.3-39.3 vs 24.0%, IQR: 20.0-30.3, p=0.0137). Similarly, the frequency of TIM⁺CD8⁺ T cells was higher in the very early recurrence group in the peripheral blood (p=0.0021), non-tumoral liver (p=0.0012), and tumor (p=0.0239).

Conclusion: The expression of immune checkpoint molecules, such as PD1 and TIM3 on T cells identified HCC patients at risk of very early IDR after PTA who would likely benefit from adjuvant immunotherapy. Thus, our study contributes to a better understanding of the potential association of PTA with adjuvant immunotherapies.

Keywords: hepatocellular carcinoma; immune checkpoint molecules; intrahepatic distant recurrence; percutaneous thermal ablation; predictive factors.

Figure 1

Flowchart of the study.

Figure 2

Immune signature associated with very early HCC recurrence after PTA. (A) Recurrence-free survival of thirty-one patients included in the study: 9 patients (29%) were later categorized into the very early recurrence group and 22 patients (71%) into the prolonged recurrence-free group. The median time between ablation procedure and intrahepatic distant recurrence was 4.5 months [IQR:3.1–9] in the very early recurrence group. (B) The frequencies of circulating PD1+ T cells compared between “prolonged free recurrence group” and “very early recurrence group”. The frequencies of PD1+ T cells, (C) in nontumoral and (D) in tumoral biopsies. (E) The frequencies of circulating TIM3+ T cells. The frequencies of TIM3+ T cells, (F) in nontumoral and (G) in tumoral biopsies. The violin plots show the distribution of the data, with median and quartiles.

Figure 3

Imaging and immunological profiles of representative patients. (A) Arterial phase axial abdominal CT scan in a 73-year-old man (patient No 13) shows a single 28-mm right liver HCC (white arrow) with peripheral perfusional disturbances at baseline. (B) Arterial phase axial abdominal CT scan of the same patient 45 months after percutaneous thermal ablation shows the ablated area (white arrowhead) without any recurrence. (C) and (E) Arterial phase axial abdominal MRI in a 66-year-old man (patient No 5) shows a single 18-mm left liver HCC (white arrow) at baseline. (D and F) Arterial phase axial abdominal CT scan in the same patient 9 months after percutaneous thermal ablation shows no recurrence at the ablated area (white arrowhead) but a very early intrahepatic distant recurrence in segment VIII (white circle). (G) Immunological profiles of patients No 13 and 5 at baseline. Results are expressed as a heat map-based frequency of positive cells compared with the mean frequency of a corresponding subpopulation of cells of the entire cohort; higher than the mean in dark blue.