Transplantation for hepatocellular carcinoma: More haste, less speed?
Authors: Tian Yang, Wan Yee Lau, Bin Huang, Myron Schwartz, Feng Shen
Journal: Hepatology (2015)

Potential conflict of interest: This study was supported by the National Natural Science Foundation of China (Nos. 81472284, 81172020 and 81372262 for Tian Yang and Jun‐Hua Lu) and State Key Project on Infectious Diseases of China (2012ZX10002‐016). To the Editor: We read with great interest the recent article by Halazun et al.1 As with what the Chinese proverb says "more haste less speed," the authors provided evidence that expediting patients with hepatocellular carcinoma (HCC) to transplant at too fast a rate may adversely affect patient outcomes. The results of this study are in marked contrast to the traditional assumption that early transplantation for HCC patients would produce better survival outcomes. We appreciate the authors' comprehensive analyses using three patient cohorts. However, we would like to raise the following comments. In this study, by comparing with the short waiting time regions (SWTRs), the long waiting time regions (LWTRs) had significantly better survivals, and the authors assumed that the better results were owing to differences in tumor biology between the two groups. The biggest limitation of this study is the lack of the data on tumor biology based on pathological examination, such as macro‐ and microscopic vascular invasions, satellites, and tumor differentiation, which have been demonstrated to be independently associated with recurrence‐free or overall survivals after transplantation for HCC.2 It is uncertain whether by enrolling these important confounding variables into the survival analyses the survival differences between the LWTRs and the SWTRs would disappear. The authors gave another explanation for the better survivals in the LWTRs: There was a higher proportion of patients who received transarterial chemoembolization (TACE) during the waiting period in this cohort. However, we should recognize that the decision to perform TACE or not varies among not only various regions and transplant centers, but also various surgeons and even individual patients with different waiting time in one same transplant center. Additionally, as a matter of fact, this study did not identify the significance of pretransplant TACE on long‐term survivals after transplantation for HCC by multivariate analyses. The propensity‐score–matched analysis has generally been used in retrospective observational studies. This analysis offers investigators the ability to balance two groups of patients across all putative risk factors, and it facilitates easy inspection of achieved balance across the measured variables.3 Therefore, it is suggested that this method be applied in this study to reduce any potential bias coming from confounding variables between the LWTRs and the SWTRs, including the variable of pretransplant TACE use during the waiting period, as well as the variables of mean donor age, expanded criteria donor, and T3 tumor at listing (which all have a P value <0.0001 in this study [Table 1]1). In conclusion, even though the data of those confounding variables concerning tumor biology based on pathological examination could not be attained from the United Network for Organ Sharing database, the propensity‐score–matched method should at least be used to decrease as much bias as possible.