Post‐transplant lymphoproliferative disorders after liver transplantation: A retrospective cohort study including 1,954 transplants

Post-transplant lymphoproliferative disorders (PTLDs) are life-threatening neoplasms after organ transplantation. Due to their rarity and multiple grades of malignancy, the incidence, outcomes, and clinicopathological features affecting patient survival after liver transplantation (LT) remain unclear. We reviewed our 1,954 LTs in 1,849 recipients (1990-2020), including 886 pediatric (<18 years) and 963 adult recipients. The following clinicopathological factors were studied: age, gender, liver etiologies, malignancy grades, Epstein-Barr virus status, performance status (PS), Ann Arbor stage, international prognostic index, and histopathological diagnosis. Of 1,849 recipients, 79 PTLD lesions (4.3%) were identified in 70 patients (3.8%). After excluding incidentally-found three autopsy cases, 67 (45 pediatric [5.1%] and 22 adult [2.3%]) patients were finally enrolled. Comorbid PTLDs significantly worsened recipient survival compared with non-complicated cases (P <0.001). The 3-/5-/10-year overall survival rates after PTLD diagnosis were 74%/66%/58%, respectively. Notably, the incidence of LT-PTLDs was significantly higher (P <0.001) with earlier onset (P =0.002) in children, while patient survival was significantly worse in adults (P =0.002). Univariate and multivariate analyses identified the following three prognostic factors: age at PTLD diagnosis ≥ 18 years (HR: 11.2, 95%CI: 2.63-47.4, P =0.001), PS ≥ 2 at diagnosis (HR: 6.77 [1.56-29.3], P =0.01), and monomorphic type (HR: 6.78 [1.40-32.9], P =0.02). A prognostic index, "LT-PTLD Score", consisting of these three factors effectively stratified patient survival and progression-free survival (P =0.003 and <0.001, respectively). In conclusion, comorbid PTLDs significantly worsened patient survival after LT. Age ≥ 18 years and PS ≥ 2 at PTLD diagnosis, and monomorphic type are independent prognostic factors, and LT-PTLD Score consisting of these three factors may allow to distinguish high-risk cases and to guide adequate interventions.