Abstract: Objective To analyze the feasibility of identifying the origin of ultra-late recurrence of liver cancer after liver transplantation  by short tandem repeat (STR) genotype. Methods The primary and recurrent lesion samples of one patient with ultra-advanced tumor recurrence after orthotopic liver transplantation in Zhongshan Hospital, Fudan University, were retrospective collected. 15 STR loci were amplified by PCR in vitro, and identified by analyzing the consistency of STR loci. Results The detection and comparison results of STR loci showed that 15 STR loci (D3S1358, vWA, D8S1179, D21S11, D18S51, D2S441, D19S433, TH01, FGA, D22S1045, D5S818, D13S317, D10S1248, D1S1656, and D12S391) in recurrent lesions were identical to those in primary lesions. with 2.28×1018 likelihood ratio. Thus, the possibility that the recurrent lesions was a new tumor was ruled out, and instead it was confirmed to be the recurrent tumor from primary lesion. Conclusions STR genotyping technology can effectively identify the origin of ultra-late recurrence after liver transplantation.

Key words: Hepatocellular carcinoma, Orthotopic liver transplantation, Ultra-late recurrence, Short tandem repeat genotyping