Liver transplantation beyond or downstaging within the Milan criteria for hepatocellular carcinoma

Unresectable hepatocellular carcinoma (HCC) is a common indication for liver transplantation (LT). The Milan criteria became standard criteria but expansion beyond the Milan criteria (tumor size and number) have resulted in similar post-transplant outcomes, thus suggesting LT is a viable treatment option for HCC presenting beyond the Milan criteria Areas covered: Expanded criteria and the use of downstaging therapies to meet Milan criteria are reviewed. Surrogates of tumor biology (including biomarkers and response to therapy) are described in detail. The controversy regarding treatment of HCV infection prior to transplant for HCC is addressed. Predictors of post-transplant recurrence and therapeutic options are explored. English-language manuscripts pertaining to LT criteria for HCC, downstaging, and tumor prognosis were reviewed. Effort was made to include manuscripts from throughout the world to ensure the reader a broad international perspective. Expert commentary: Patients can be successfully transplanted with HCC beyond Milan criteria, or patients beyond Milan criteria can be downstaged to within Milan criteria and achieve successful post-liver transplant outcomes. The current reliance on tumor burden (size and number) alone ignores the mounting data supporting the prognostic use of additional surrogates of tumor biology in identifying appropriate candidates.