Are Ki-67 and Procalcitonin Expression Levels Useful in Predicting the Biological Behavior of Hepatocellular Carcinoma After Liver Transplantation?

: Examinations of procalcitonin (PCT) and Ki-67 expression levels in hepatocellular carcinoma (HCC) patients who have undergone liver transplantation (LT) through immunohistochemical analyses of tumor tissue may reveal the biological characteristics of the tumor, thus informing the selection of HCC patients for LT. : Hepatectomy specimens from 86 HCC patients who underwent LT were obtained and analyzed immunohistochemically for the expression of PCT and Ki-67. The percentage and intensity of PCT staining, as well as the percentage of Ki-67 expression, were assessed for each patient. The impacts of PCT and Ki-67 expression on disease-free survival, overall survival, and the recurrence rate were studied, as well as their correlations with other clinicopathological features. : The recurrent HCC group showed a higher Ki-67 level ( < 0.001), larger maximum dominant tumor diameter ( < 0.001), and higher rate of vascular invasion ( = 0.001). The pre-transplant AFP ( = 0.001), maximum dominant tumor diameter ( < 0.001), number of tumor nodules ( < 0.001), rate of vascular invasion ( = 0.001), and Ki-67 level ( = 0.044) were higher in patients beyond the Milan criteria. Similarly, the pre-transplant AFP ( < 0.001); maximum dominant tumor diameter ( < 0.001); number of tumor nodules ( < 0.001); rates of portal vein tumor thrombus ( = 0.002), poor differentiation ( = 0.021), and vascular invasion ( < 0.001); and Ki-67 level ( = 0.010) were higher in patients beyond the expanded Malatya criteria. The maximum dominant tumor diameter ( = 0.006); Ki-67 level ( = 0.003); rates of vascular invasion ( < 0.001), cases beyond the Milan criteria ( = 0.042) and the expanded Malatya criteria ( = 0.027), and portal vein tumor thrombus ( = 0.020); and presence of recurrence ( < 0.001) were higher in HCC patients with mortality. The Kaplan-Meier estimates indicated that Ki-67 levels exceeding 5% significantly affected DFS and OS. Although the Kaplan-Meier estimates indicated that a PCT staining percentage of ≥25% did not have a statistically significant effect on DFS or OS, the outcomes may be considered clinically significant. : This study demonstrated that the Ki-67 proliferation index can be used as a predictive biomarker of the biological behavior of HCC. Furthermore, we claim that PCT expression over a particular threshold might impact recurrence and survival, and we believe that further multicenter prospective studies focused on standardized PCT antibody staining are crucial in order to determine its potential as a biomarker for HCC.