Endothelial angiopoietin-2 overexpression in explanted livers identifies subjects at higher risk of recurrence of hepatocellular carcinoma after liver transplantation

Abstract

BackgroundThough the precise criteria for accessing LT are consistently being applied, HCC recurrence (HCC-R_LT) still affects more than 15% of the patients. We analyzed the clinical, histopathological, and biological features of patients with HCC to identify the predictive factors associated with cancer recurrence and survival after LT.MethodsWe retrospectively analyzed 441 patients with HCC who underwent LT in our center. Overall, 70 (15.8%) of them developed HCC-R_LT. We matched them by age at transplant and etiology with 70 non-recurrent patients. A comparable cohort from the Liver Transplant Centre of Bologna served as validation. The clinical and biochemical characteristics and pre-LT criteria (Milan, Metroticket, Metroticket_AFP, and AFP model) were evaluated. Histological analysis and immunohistochemistry for angiopoietin-2 in the tumor and non-tumor tissue of explanted livers were performed. Patients’ follow-up was until death, last clinical evaluation, or 31 December 2021. In patients with HCC-R_LT, the date of diagnosis of recurrence and anatomical site has been reported; if a biopsy of recurrence was available, histologic and immunohistochemical analyses were also performed.ResultsPatients were followed up for a mean period of 62.7 ± 54.7 months (median, 39 months). A higher risk of HCC-R_LT was evident for factors related indirectly (AFP) or directly (endothelial angiopoietin-2, microvascular invasion) to biological HCC aggressiveness. In multivariate analysis, only angiopoietin-2 expression was independently associated with recurrence. Extremely high levels of endothelial angiopoietin-2 expression were also found in hepatic recurrence and all different metastatic locations. In univariate analysis, MELD, Metroticket_AFP Score, Edmondson–Steiner grade, microvascular invasion, and endothelial angiopoietin-2 were significantly related to survival. In multivariate analysis, angiopoietin-2 expression, Metroticket_AFP score, and MELD (in both training and validation cohorts) independently predicted mortality. In time-dependent area under receiver operating characteristic curve analysis, the endothelial angiopoietin-2 expression had the highest specificity and sensitivity for recurrence (AUC 0.922, 95% CI 0.876–0.962, p < 0.0001).ConclusionsEndothelial angiopoietin-2 expression is a powerful independent predictor of post-LT tumor recurrence and mortality, highlighting the fundamental role of tumor biology in defining the patients’ prognosis after liver transplantation. The great advantage of endothelial angiopoietin-2 is that it is evaluable in HCC biopsy before LT and could drive a patient’s priority on the waiting list.

Indolent cancer and pattern of progression: Two missing parameters in trial design for hepatology

“…It was firstly validated in a prospective multicenter cohort of patients with HCC treated with sorafenib conducted in Italy, then another in Japan, and also in patients treated with regorafenib, ramucirumab, and radioembolization. [56][57][58][59][60] Additionally, a recent meta-analysis evaluating sorafenib benefit in patients with intermediate/advanced HCC, showed that macro-vascular invasion and extrahepatic spread were significantly associated with rapid progression at multivariable meta-regression analysis. [58] This may seem self-evident since these variables related to tumor burden are those which define the advanced stage according to BCLC classification compared to the intermediate stage.…”

“…In fact, presence or absence of many biological features, that are classically linked to aggressiveness of HCC (microvascular invasion, satellite nodules, diffuse infiltrating growth, poorly differentiated HCC, mixed HCC-cholangiocarcinoma, "poor prognostic molecular signature", and high AFP), are associated with high risk of recurrence after resection or LT, failure of local control with local regional therapies, early progression, and finally lead to poor prognosis. In this line, an Italian study showed that endothelial angiopoietin-2 overexpression in explanted livers independently predicts the risk of HCC recurrence and death after LT. [60] However, except for AFP in the field of LT, which is used as a surrogate to differentiate tumor aggressiveness, there is no consensus on how to incorporate huge molecular heterogeneity into tumor staging.…”

“…The impact of the pattern of progression on the postprogression survival represents a good example of evolutionary events in patients with HCC. It was firstly validated in a prospective multicenter cohort of patients with HCC treated with sorafenib conducted in Italy, then another in Japan, and also in patients treated with regorafenib, ramucirumab, and radioembolization 56–60 . Additionally, a recent meta-analysis evaluating sorafenib benefit in patients with intermediate/advanced HCC, showed that macro-vascular invasion and extrahepatic spread were significantly associated with rapid progression at multivariable meta-regression analysis 58 …”

Differential Impact of Tumor Endothelial Angiopoietin-2 and Podoplanin in Lymphatic Endothelial Cells on HCC Outcomes with Tyrosine Kinase Inhibitor Treatment According to Sex

“…It is clear that these patients, who were only eligible for systemic therapy after failing more curative treatments, were at an advanced stage with expected extra-hepatic spread, which aligns with high podoplanin levels. From this perspective, the elevated endothelial Ang2 levels also indicate aggressive disease [25,26]. Notably, females, showing the highest podoplanin and Ang2 levels, responded better to TKI therapy, had longer overall survival, and remained on treatment longer compared to males, who exhibited lower levels of these markers.…”

Therapeutic Approach to Post-Transplant Recurrence of Hepatocellular Carcinoma: Certainties and Open Issues

“…Patients experiencing HCC recurrence showed significantly increased expression of angiopoietin-2 in tumor endothelium but not in the hepatocyte at explant pathology. Univariate analysis identified BMI, log AFP at transplant, endothelial angiopoietin-2 expression, Milan criteria, Metroticket AFP score, and the AFP model as significantly associated with recurrence, while in multivariate analysis angiopoietin-2 expression was the only independent factor associated with recurrence (HR: 5.634, 95% CI 2.597-12.294, p < 0.001) [50].…”