Liver transplantation for primary and secondary liver tumors: Patient-level meta-analyses compared to UNOS conventional indications

Background and Aims: Liver transplant (LT) for transplant oncology (TO) indications is being slowly adopted worldwide and has been recommended to be incorporated cautiously due to concerns about mid-long-term survival and its impact on the waiting list. Approach and Results: We conducted 4 systematic reviews of all series on TO indications (intrahepatic cholangiocarcinoma and perihilar cholangiocarcinoma [phCC]) and liver metastases from neuroendocrine tumors (NETs) and colorectal cancer (CRLM) and compared them using patient-level meta-analyses to data obtained from the United Network for Organ Sharing (UNOS) database considering conventional daily-practice indications. Secondary analyses were done for specific selection criteria (Mayo-like protocols for phCC, SECA-2 for CRLM, and Milan criteria for NET). A total of 112,014 LT were analyzed from 2005 to 2020 from the UNOS databases and compared with 345, 721, 494, and 103 patients obtained from meta-analyses on intrahepatic cholangiocarcinoma and phCC, and liver metastases from NET and CRLM, respectively. Five-year overall survival was 53.3%, 56.4%, 68.6%, and 53.8%, respectively. In Mantel-Cox one-to-one comparisons, survival of TO indications was superior to combined LT, second, and third LT and not statistically significantly different from LT in recipients >70 years and high BMI. Conclusions: Liver transplantation for TO indications has adequate 5-year survival rates, mostly when performed under the selection criteria available in the literature (Mayo-like protocols for phCC, SECA-2 for CRLM, and Milan for NET). Despite concerns about its impact on the waiting list, some other LT indications are being performed with lower survival rates. These oncological patients should be given the opportunity to have a definitive curative therapy within validated criteria.