Liver transplant for combined hepatocellular-cholangiocarcinoma: United States outcomes and influence of the MMaT-3 policy: United States outcomes and influence of the MMaT-3 policy

Introduction: There is absence of updated population-level data for liver transplantation (LT) for combined hepatocellular–cholangiocarcinoma (cHCC-CCA) and on the impact of current allocation practices, including the Median MELD at Transplant minus 3 (MMaT-3) policy era. Methods: Using the UNOS registry, we compared adult LT candidates and recipients with cHCC-CCA, hepatocellular carcinoma (HCC), and cholangiocarcinoma (CCA). Outcomes included waitlist mortality (WM), waitlist dropout (WD), graft survival (GS), and patient survival (PS), analyzed using Kaplan–Meier, multivariable Cox regression, and Fine–Gray competing risk models stratified by policy era. Results: 309 candidates had cHCC-CCA. At 3 years, cHCC-CCA had the lowest WM (4.6%) and WD (29.0%) compared with CCA (27.7%, 64.9%) and HCC (15.6%, 39.8%) (P < 0.001). After adjustment, cHCC-CCA was associated with reduced WD (HR 0.56, P = 0.008) and WM (HR 0.33, P = 0.028). Conversely, 15-year GS (25.5%) and PS (27.3%) were lowest for cHCC-CCA (both P < 0.001), with higher adjusted risk of graft loss (HR 1.79) and mortality (HR 1.67). Notably, cHCC-CCA post-LT survival improved from the pre-MMaT-3 to the post-MMaT-3 era. Conclusion: cHCC-CCA exhibits favorable waitlist, yet lower long-term post-LT survival compared with HCC and CCA. The improved outcomes observed in the MMaT-3 era suggest that refined selection may have optimized post-LT survival in cHCC-CCA.