Methods

This single-center study included consecutive patients with liver cancer who underwent LT at the Nanjing Drum Tower Hospital in China during the January 2018-September 2020 period. Inclusion criteria included receiving liver transplantation(LT) for the first time, diagnosis of liver cancer (HCC, CC, or other types) confirmed by histopathology of the resected liver, and age>18 years. Exclusion criteria were death within the first month after LT and a switch to non-Tac based immunosuppression. Tacrolimus TTR was calculated using linear interpolation from the date of transplantation until recurrence or the last follow-up according to target ranges recommended in the Chinese guideline and intemational expert consensus.

Result

The differences in CET90, mean Tac trough level, CTTR, and ITTR between the recurrence and nonrecurrence groups are illustrated in Figure 1. Only CTTR results were significant (z = 4.208, P＜0.001). Receiver-operating characteristic curve analysis demonstrated a higher AUC for CTTR, compared with that of ITTR (0.795 vs. 0.604, respectively; x² = 4.91, P = 0.027).

The recipients were subsequently divided into high-TTR and low-TTR groups according to the CTTR and ITTR cutoff values. The Kaplan–Meier survival curves shown in Figure 3 indicated that the recurrence-free time of both the high-CTTR and high-ITTR groups was significantly higher than that of the low-TTR group (log-rank test: P ＜0.001 for CTTR and P = 0.025 for ITTR).

CTTR and mean Tac trough level were independent predictors of post-LT recurrence of liver cancer (Table 2).

TTR predicts liver cancer recurrence in liver transplant recipients. The range of tacrolimus concentrations recommended in the Chinese guideline was more beneficial than that recommended in the international consensus for Chinese patients undergoing liver transplantation for liver cancer. This study suggests that maintaining Tac levels within therapeutic ranges is crucial for postoperative management.