Transplant Oncology: An Evolving Field in Cancer Care

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.

Keywords: cholangiocarcinoma; circulating tumor DNA; colorectal cancers; hepatocellular carcinoma; immunotherapy; liver metastases; liver transplantation; neuroendocrine tumor; transplant oncology.

Figure 1

Concept map of transplant oncology. Multidisciplinary collaborative approach to maximize the care of cancer patients through transplantation.

Figure 2

Historical expansions of the Milan criteria for liver transplantation in patients with hepatocellular carcinoma. yr: year; OS, overall survival; RFS, relapse-free survival; ∑, summation; AFP, alpha-fetoprotein; TTV, total tumor volume; ml, milliliters; cm, centimeters; ng, nanograms.

Figure 3

Current prospective trials on liver transplantation for colorectal liver metastases. NCT, National Clinical Trial; CT, chemotherapy; LDLT, living donor liver transplantation; CRLM, colorectal Liver Metastases; LT, liver transplantation; TACE, transarterial chemoembolization; S, stage; SIRT, selective Internal Radiation Therapy; RCT, randomized controlled trial; RPVL, right portal vein ligation; A-E, name of countries as flagged off.

Figure 4

Utility of ctDNA in HCC for minimal residual disease evaluation and surveillance: pros and cons in comparison with tissue biopsy. (+) advantages (−) disadvantages.