Transplant Oncology: An Emerging Discipline of Cancer Treatment

Abstract

Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The applications of oncology, transplant medicine, and surgery are the core of transplant oncology to improve patients’ survival and quality of life. The main concept of transplant oncology is to radically cure cancer by removing the diseased organ and replacing it with a healthy one, aiming to improve the survival outcomes and quality of life of cancer patients. Subsequently, it seeks to expand the treatment options and research for hepatobiliary malignancies, which have seen significantly improved survival outcomes after the implementation of liver transplantation (LT). In the case of colorectal cancer (CRC) in the transplant setting, where the liver is the most common site of metastasis of patients who are considered to have unresectable disease, initial studies have shown improved survival for LT treatment compared to palliative therapy interventions. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years beyond Milan criteria in a stepwise manner. However, the outcome improvements and overall patient survival are limited to the specifics of the setting and systematic intervention options. This review aims to illustrate the representative concepts and history of transplant oncology as an emerging discipline for the management of hepatobiliary malignancies, in addition to other emerging concepts, such as the uses of immunotherapy in a peri-transplant setting as well as the use of circulating tumor DNA (ctDNA) for surveillance post-transplantation.

Cholangiocarcinoma: The Current Status of Surgical Options including Liver Transplantation

“…Patients who are ineligible for surgical resection due to factors such as tumor size, location, or liver disease can have OLT as a potential alternative treatment option [ 129 , 130 ]. Although OLT used to be contraindicated in hilar CCA, the introduction of neoadjuvant radio-chemotherapy, which was implemented and supplemented with OLT by the Mayo Clinic, shed light on the role of OLT in CCA management [ 18 , 131 , 132 , 133 , 134 , 135 , 136 , 137 ]. Common reasons for failing to attain R0 resection include difficulties in identifying the hepatic duct and removing implicated adjacent tissues, such as the caudate lobe.…”

“…Historically, OLT was infrequently considered for iCCA due to its aggressive characteristics, with initial data showing a modest 5-year survival rate ranging from 10% to 18%. Currently, HCC predominates as an OLT indication, yet there is a renewed interest in evaluating the suitability of iCCA for OLT [ 16 , 17 , 18 , 20 , 21 , 22 , 137 , 142 , 143 ]. Recent findings indicate that OLT could be a viable choice for individuals with small iCCA tumors.…”

“…These suboptimal results can be attributed to the absence of uniform patient selection criteria and the limited use of neoadjuvant therapies. A significant shift in this landscape emerged when precise patient selection criteria were demonstrated, particularly in enhancing survival outcomes in OLT for early-stage liver cancers [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Therefore, understanding the evolving landscape of surgical treatment options becomes increasingly critical.…”

Dd-cfDNA in liver transplantation: The future of non-invasive liver graft evaluation

“…It is known that liver transplantation is an evidence-based worldwide accepted treatment option for patients with liver tumors [64]. Usually, LT is performed in patients with hepatocellular cancer (HCC) according to Milan criteria, but in recent years, it has been applied in a series of patients with cholangiocarcinoma as well [65][66][67].…”

Utilization of Immunotherapy as a Neoadjuvant Therapy for Liver Transplant Recipients with Hepatocellular Carcinoma

“…Orthotopic liver transplantation (OLT) has emerged as a highly effective treatment option for unresectable HCC in patients meeting the Milan criteria, which specify a maximum tumor diameter of 5 cm for a single lesion or no more than three tumors, each less than or equal to 3 cm, without vascular invasion or extrahepatic metastases [ 5 , 6 , 7 ]. However, in the US, the United Network for Organ Sharing (UNOS) exception points are available to patients within Milan or to those whose tumors have been successfully downstaged and are subsequently eligible for deceased donor allocation.…”