The predictive role of preoperative serum glutamate dehydrogenase levels in microvascular invasion and hepatocellular carcinoma prognosis following liver transplantation-a single center retrospective study

Background: As a critical metabolic substrate, glutamine is not only involved in the progression of many cancers but is also related to angiogenesis. Glutamate dehydrogenase (GLDH), a key enzyme in glutamine metabolism, has been reported to regulate tumor proliferation; however, its relationship with microvascular invasion (MVI) is unclear. This study evaluated the ability of preoperative serum GLDH levels to predict MVI and the long-term survival of hepatocellular carcinoma (HCC) patients after liver transplantation (LT). Methods: HCC patients that underwent LT from January 2015 to May 2020 at the First Affiliated Hospital of Sun Yat-Sen University were enrolled in our retrospective analysis. Clinicopathological variables were extracted from medical records. A receiver operating characteristic curve was created to determine the optimal cut-off value of GLDH for MVI. Results: Preoperative GLDH was significantly elevated in the MVI-positive group (U = 454.00, p = 0.000). The optimal cut-off value of GLDH for MVI was 7.45 U/L, with an area under the curve of 0.747 (95% CI [0.639-0.856], p = 0.000). The sensitivity was 79.3%, while the specificity was 64.5%. GLDH > 7.45 U/L (p = 0.023) and maximum diameter >5 cm (p = 0.001) were independent risk factors for the presence of MVI. Patients with GLDH > 7.45 U/L had significantly poorer overall survival (p = 0.001) and recurrence-free survival (p = 0.001) after LT than patients with GLDH ≤ 7.45 U/L. Similarly, patients with MVI were associated with poor survival (p = 0.000). Conclusions: Preoperative elevated serum GLDH levels predict MVI and poorer long-term survival for HCC after LT.