Transplantation for Peri-Hilar and Intrahepatic Cholangiocarcinoma With mTOR Immunosuppression

Abstract

Background: Cholangiocarcinoma (CCA) has rising incidence and mortality rates. Outcomes from combination systemic, loco-regional therapy (LRT) and liver transplantation (LT) are improving, but more granular data are needed to inform evidence-based management, including patient selection and immunosuppression. Methods: Patients with peri-hilar (PH) and intrahepatic (IH) CCA who underwent LT at a single center between January 2008 and February 2023 were reviewed retrospectively. Primary outcomes were overall survival (OS) and recurrence-free survival (RFS) with significance determined by Cox proportional hazards model. Results: During the study period, 53 patients underwent LT for either PH (n = 27), or IH (26). Cohort had mean age 58.5 years old (IQR, 47.0-63.0), body mass index (BMI) 25.9 (IQR, 22.9-30.0) kg/m2, and mean biologic MELD 9 (IQR, 7-17). Most frequent etiology was PSC (n = 12, 22.6%). Forty-nine patients (92.5%) received neoadjuvant therapy, including systemic (n = 48, 90.6%) and locoregional therapy (LRT) (n = 22, 41.5%), to which PH tumors were both most and least responsive (P = .03). On explant pathology, tumor were a median size of 3.5 cm and lympho-vascular invasion (LVI) was present in 13 (24.5%) cases. Median follow-up post-transplant was 910 days (IQR, 407-1509). Probabilities of OS and RFS at 3-years post-LT were 69.2% (95% CI, 56.9%-84.2%) and 57.4% (95% CI, 43.7%-75.4%). In multivariable analysis, OS was associated with tumor type and LVI, and RFS with age, BMI, PSC and LRT. After a median post-LT period of 38 days (IQR, 27-79.5), 39 (71.7%) patients started mTOR inhibition with lowered tacrolimus goal. Cox proportional hazard model showed significant association of OS with mTOR inhibition, though this was not validated by a time-dependent co-variate approach. Conclusions: In this single center cohort of CCA, post-LT outcomes were significantly greater for patients with IH tumors and no LVI. Immunosuppression with mTOR inhibition was not consistently associated with outcomes.