Transplantation for Hepatocellular Carcinoma: Is There a Tumor Size Limit?

The advent of tumor-size-based criteria (Milan and University of California, San Francisco [UCSF]) for the transplantation of hepatocellular carcinomas (HCC) has facilitated tumor patients' access to transplantation. Recent success in transplanting patients with larger tumors (beyond UCSF) necessitates an understanding of the patient, the tumor, and biological criteria that determine successful outcomes for HCC transplantation across all size criteria.

We analyzed 11,928 patients who received OLT between 2002 and 2013 from the United Network for Organ Sharing Standard Transplant Analysis and Research file. Clinical outcomes were compared by tumor size at transplant; Milan (n = 11,555), beyond Milan within UCSF (n = 291), and beyond both Milan and UCSF (n = 82). A statistical analysis was conducted to determine the factors impacting survival.

There were no statistically significant differences in the 1-, 3-, and 5-year survival rates between the 3 patient groups (within Milan 91.1%, 74.8%, and 60.3%; beyond Milan within UCSF, 92.7%, 71.1%, and 51.6%; and beyond Milan and UCSF 95.8%, 75.9%, and 58.1%). In a multivariate analysis, factors significantly affecting survival included, AA race, AFP >3000, and hepatitis C infection, while age, diabetes and largest tumor diameter had a more modest impact. Total tumor burden and time to transplantation were not significant predictors of survival.

These data indicate that, based on current clinical selection criteria, a small number of large tumors can be successfully treated by transplantation and points to the need to include markers of HCC biologic behavior beyond size and tumor burden to transplant criteria.