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

BACKGROUND: Hepatocellular carcinoma (HCC) carries a poor prognosis. Liver transplantation (LT) is potentially curative for localized HCC. We evaluated the impact of LT on U.S. general population HCC-specific mortality rates.
METHODS: The Transplant Cancer Match Study links the U.S. 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.
RESULTS: Among 129,487 HCC cases, 45.9% had localized cancer. HCC incidence increased on average 4.0% annually [95% confidence interval (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 nontransplanted 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.
CONCLUSIONS: 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 patients without transplants have limited the impact of transplantation on general population HCC-specific mortality rates. IMPACT: Although LT rates continue to rise, better screening and treatment modalities are needed to halt the rising HCC mortality rates in the United States.See related commentary by Zhang and Thrift, p. 435. ©2020 American Association for Cancer Research.