Role of Intrahepatic Regional Immunity in Post-Transplant Cancer Recurrence

Abstract

Hepatic malignancy is a major indication for liver transplantation; however, post-transplant cancer recurrence is an emerging clinical challenge affecting long-term outcomes. Pre-transplant tumor biology, staging, and post-transplant immunosuppression regimens have been elucidated as risk factors for recurrent liver cancer. However, increasing evidence indicates that hepatic ischemia and reperfusion (IR) injury to allografts are crucial to providing a favorable immunologic microenvironment for cancer cell invasiveness and metastasis after liver transplantation. The association of severe graft injury in marginal grafts, such as small-for-size or fatty grafts, with lower recurrence-free survival rates in living donor liver transplantations, substantiates the correlation between hepatic IR injury and cancer recurrence. IR has been demonstrated to trigger intrahepatic immunological microenvironment remodeling, including pro-inflammatory responses exacerbating graft injury and anti-inflammatory responses promoting tissue repair. However, the role of regional immunity in post-transplant cancer recurrence is not comprehensively understood. This review describes the up-to-date evidence of the intrahepatic humoral microenvironment and regional regulatory immunological microenvironment induced by IR injury, as well as their roles in cancer recurrence after liver transplantation. A comprehensive understanding of regional immunity will provide novel precise diagnostic, therapeutic, and prognostic strategies for post-transplant cancer recurrence.