Objective  To investigate the clinical prognosis of the liver transplant recipients diagnosed with hepatocellular carcinoma (HCC) complicated with microvascular invasion (MVI).

  Methods  Clinical data of 3 447 HCC recipients undergoing liver transplantation were extracted from Surveillance, Epidemiology, and End Results (SEER) database of American National Cancer Institute. According to the incidence of MVI, all recipients were divided into MVI (n=376) and non-MVI groups (n=3 071). The clinical prognosis of liver transplant recipients was statistically compared between two groups by analyzing the 1-, 3- and 5-year overall survival (OS) and liver cancer specific survival (LCSS). Relevant clinical data including age, gender, race, pathological staging, tumor size, lymph node metastasis, distant metastasis, tumor-node-metastasis (TNM) staging and MVI were recorded in two groups. The independent risk factors of clinical prognosis of HCC recipients undergoing liver transplantation were analyzed by multivariate Cox regression model. The nomogram for predicting the clinical prognosis of the recipients was delineated. The accuracy of the prediction model was evaluated by the consistency index.

  Results  In the non-MVI group, the 1-, 3-, 5-year OS and LCSS were 93.5%, 82.1%, 75.3% and 98.3%, 93.8%, 90.7%, significantly higher than 88.8%, 72.1%, 68.4% and 95.3%, 83.1%, 80.4% in the MVI group (all P < 0.05). Multivariate regression analysis showed that pathological staging, tumor size, lymph node metastasis, distant metastasis, TNM staging and MVI were the independent risk factors of OS and LCSS in HCC recipients undergoing liver transplantation (all P < 0.05). The nomogram consistency index was calculated as 0.624 (0.602-0.648).

  Conclusions  MVI is an independent risk factor of the clinical prognosis of HCC recipients undergoing liver transplantation, which is significantly correlated with poor prognosis of the recipients. The nomogram based on MVI can predict the clinical prognosis of these recipients.