AUTHOR=Kang Woo-Hyoung , Hwang Shin , Moon Deok-Bog , Kim Ki-Hun , Ahn Chul-Soo , Ha Tae-Yong , Song Gi-Won , Jung Dong-Hwan , Park Gil-Chun , Yoon Young-In , Na Byeong-Gon , Kim Sang-Hoon , Kim Sung-Min , Lee Sung-Gyu 
  
TITLE=ABO-incompatibility and hepatocellular carcinoma recurrence after living donor liver transplantation: stratified by tumor burden
  
JOURNAL=Transplant International
  
VOLUME=Volume 39 - 2026
  
YEAR=2026
  
URL=https://www.frontierspartnerships.org/journals/transplant-international/articles/10.3389/ti.2026.17121
  
DOI=10.3389/ti.2026.17121
  
ISSN=1432-2277
  
ABSTRACT=ABO-incompatible (ABOi) living donor liver transplantation (LDLT) requires rituximab-based desensitization and intensified early immunosuppression, and whether this promotes hepatocellular carcinoma (HCC) recurrence remains controversial. We hypothesized that this effect depends on tumor burden, assessed morphologically (Milan criteria) and biologically (ADV score). In this single-center study, we analyzed 1,573 adults transplanted for HCC (ABOi, n = 316; ABO-compatible [ABOc], n = 1,257); the primary endpoint was recurrence-free survival (RFS). Crude recurrence was similar (21.8% vs. 20.7%; P = 0.64) despite a lower tumor burden in ABOi recipients. In a propensity score-matched cohort, RFS did not differ overall (hazard ratio 1.11, 95% CI 0.82–1.48), but beyond Milan recurrence was higher in ABOi recipients (53.7% vs. 38.5%; adjusted HR 1.45, 95% CI 1.00–2.09), whereas within Milan it was identical (13.3% vs. 13.4%). The same pattern held for tumor biology: recurrence was higher in ABOi only at ADV ≥5log (64.0% vs. 44.6%; P = 0.022). Higher early tacrolimus exposure in ABOi recipients was associated with recurrence. Overall survival was similar (P = 0.91). ABO-incompatibility did not compromise survival. Recurrence was higher in ABOi recipients with a high tumor burden by either measure, although the formal interaction tests were not significant (P = 0.23 and P = 0.088). These exploratory subgroup findings are hypothesis-generating and support closer early surveillance.