Transplant Oncology: An Evolving Field in Cancer Care

SIMPLE SUMMARY: Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The application of oncology, transplant medicine, and surgery to improve patients’ survival and quality of life is the core of transplant oncology. This review illustrates the concept and history of transplant oncology as an evolving field for the management of hepatocellular carcinoma, intrahepatic biliary cancer, and liver-only metastasis of non-hepatobiliary carcinoma. The utility of immunotherapy in the transplant setting is discussed as well as the feasibility of using circulating tumor DNA for surveillance post-transplantation. As transplant oncology continues to evolve as a promising field in cancer management, it is expected that there will be improved outcomes and expansion of transplant eligibility through the consolidation of multidisciplinary and collaborative efforts. Liver transplantation is increasingly associated with improved survival outcomes in patients with liver malignancies. Eligibility criteria for liver transplantation has expanded over the years to include more patients with cancer. In addition, immunotherapy and ctDNA are two emerging concepts that are highly applicable to transplant oncology treatment. Immunotherapy may be used as neoadjuvant “bridging” therapy pre- liver transplantation and possibly in the palliative setting post-transplantation. Liquid biopsy to assess ctDNA post-transplantation can potentially be used as a biomarker to detect minimal residual disease and disease recurrence. ABSTRACT: Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The application of oncology, transplant medicine, and surgery to improve patients’ survival and quality of life is the core of transplant oncology. Hepatobiliary malignancies have been treated by liver transplantation (LT) with significant improved outcome. In addition, as the liver is the most common site of metastasis for colorectal cancer (CRC), patients with CRC who have stable unresectable liver metastases are good candidates for LT, and initial studies have shown improved survival compared to palliative systemic therapy. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years in a stepwise manner; however, they have only been shown to improve patient survival in the setting of limited systemic therapy options. This review illustrates the concept and history of transplant oncology as an evolving field for the management of hepatocellular carcinoma, intrahepatic biliary cancer, and liver-only metastasis of non-hepatobiliary carcinoma. The utility of immunotherapy in the transplant setting is discussed as well as the feasibility of using circulating tumor DNA for surveillance post-transplantation.