Transplant Oncology: An Emerging Discipline of Cancer Treatment

Simple Summary Transplant oncology is an evolving treatment ideal for patients suffering from various cancers with poor prognoses. The concept essentially is the complete removal and replacement of a diseased organ with that of a healthy donor, in order to improve the patient's lifespan and quality of life. To attain this goal, multiple disciplines within the transplant field have converged to improve treatment plans by adjusting drug regimens and surgical techniques throughout multiple studies to increase survival results. Several of these studies have focused on hepatobiliary illnesses and therefore shown significant benefits to patient's after receiving liver transplantation, in varying disease settings including, but not limited to hepatocellular carcinoma and colorectal cancer. As well as, expanding systematic drug therapies in different settings of cancer treatment, before curative surgery to allow a greater population to reach Milan criteria, and ultimately qualify for transplantation, and afterward in cases of disease recurrence. This article is a review of the current outlook of the transplant field for hepatobiliary cancers including treatment management, the history of emerging radical surgery, as well as the drug regimens, and other innovations that are also improving quality of life and patient survival.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.