Liver cancer understaging in liver transplantation in the current era of radiologic imaging and newer generation locoregional therapies

Background: Discordance in hepatocellular carcinoma (HCC) staging between pre-transplant imaging and explant pathology is associated with an increased risk of recurrence and death. Our aim was to evaluate variables that predicted concordance/discordance in the era of new generation locoregional therapies (LRT) and improved radiologic technology in diagnosis. Methods: A single-center retrospective study was performed on patients who received a liver transplant for HCC between 2008-2019. Pre- and post-LT variables, including type of LRT, downstaging (DS), transplant time period, and radiologic response to LRT, were analyzed for concordance/discordance. Kaplan-Meier analysis was used to assess post-LT survival. Results: Of 146 patients transplanted within Milan Criteria (MC), discordance rates (understaged) were 45%. Discordance was associated with ≥ 3 HCC lesions at diagnosis but not newer generation LRT (transarterial radioembolization/ stereotactic body radiation therapy), traditional LRT or combination. No differences in discordance were seen between transplant periods (2008-2013 vs. 2014-2019), but those within MC in the earlier period had higher concordance rates. A trend was observed between DS and discordance. Conclusion: HCC stage discordance remains common and poorly predictable. Discordance was associated with three or more HCC lesions at the time of diagnosis. Patients within MC transplanted between 2008-2013 was associated with concordance, while a trend was noted between DS and discordance. No other pre- or post- LT variables predicted discordance/ concordance. Discordance was associated with decreased survival.