The Impact of Liver Transplantation on Hepatocellular Carcinoma Mortality in the United States.

Hepatocellular carcinoma (HCC) carries a poor prognosis. Liver transplantation (LT) is potentially curative for localized HCC. We evaluated the impact of LT on US general population HCC-specific mortality rates. The Transplant Cancer Match Study links the US transplant registry with 17 cancer registries. We calculated age-standardized incidence (1987-2017) and incidence-based mortality (IBM) rates (1991-2017) for adult HCCs. We partitioned population-level IBM rates by cancer stage and calculated counterfactual IBM rates assuming transplanted cases had not received a transplant. Among 129,487 HCC cases, 45.9% had localized cancer. HCC incidence increased on average 4.0% annually (95%CI=3.6%-4.5%). IBM also increased for HCC overall (2.9% annually; 95%CI=1.7%-4.2%) and specifically for localized stage HCC (4.8% annually; 95%CI=4.0%-5.5%). The proportion of HCC-related transplants jumped sharply from 6.7% (2001) to 18.0% (2002), and further increased to 40.0% (2017). HCC-specific mortality declined among both non-transplanted and transplanted cases over time. In the absence of transplants, IBM for localized HCC would have increased at 5.3% instead of 4.8% annually. LT has provided survival benefit to patients with localized HCC. However, diagnosis of many cases at advanced stages, limited availability of donor livers, and improved mortality for non-transplanted patients have limited the impact of transplantation on general population HCC-specific mortality rates. Though LT rates continue to rise, better screening and treatment modalities are needed to halt the rising HCC mortality rates in the US. Copyright ©2020, American Association for Cancer Research.