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How far can we go with hepatocellular carcinoma in living donor liver transplantation?

Limkemann, Ashley J.P.; Abreu, Phillipe; Sapisochin, Gonzalo

Current Opinion in Organ Transplantation: October 2019 - Volume 24 - Issue 5 - p 644–650
doi: 10.1097/MOT.0000000000000692
HOT TOPICS IN LIVING DONOR LIVER TRANSPLANTATION: Edited by Henrik Petrowsky
Free

Purpose of review Living donor liver transplantation (LDLT) in the setting of hepatocellular carcinoma (HCC) has been adopted worldwide over the past decade. Many centers have implemented LDLT because of the limited supply of deceased organs, which has also provided an opportunity for centers to expand the indication for transplantation for patients with HCC.

Recent findings Center-specific expanded HCC criteria have proven to be well tolerated in terms of overall and disease-free survival when compared with the standard, Milan criteria. There is a need to overcome size and number as the sole limiters. New technologies to better predict outcomes after liver transplantation for HCC, response to treatments and/or bridging therapies while waiting for a liver transplantation, along with determining tumour behaviour are being incorporated into criteria. Improved outcomes of LDLT for all causes has increased utilization of the procedure for HCC patients worldwide.

Summary LDLT has become a great treatment option for HCC patients. Progressively better understanding of tumour behaviour and different surrogates of tumour biology assessments will allow better patient selection for LDLT.

Multi-Organ Transplant Program, Department of Surgery, University Health Network/University of Toronto, Toronto, Ontario, Canada

Correspondence to Gonzalo Sapisochin, MD, PhD, MSc, 585 University Avenue, Toronto, ON, Canada M5G 2N2. Tel: +1 416 340 5169; e-mail: gonzalo.sapisochin@uhn.ca

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INTRODUCTION

Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer with increasing incidence, ranking sixth amongst all cancers in incidence and fourth for cancer-related mortality worldwide [1]. Liver transplantation is potentially curative by removing the cancer and diseased liver. For decades, restricting HCC patients from liver transplantation with Milan criteria for recipient selection was used to ensure low recurrence posttransplantation and maintaining an acceptable postliver transplantation survival. In contrast to deceased donor liver transplantation (DDLT), recipient selection for living donor liver transplantation (LDLT) is not limited by organ allocation systems. Subsequently, many centers have developed center-specific expanded criteria with acceptable results, including University of California San Francisco criteria, Extended Toronto criteria, amongst others [2–4].

Box 1

Box 1

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RECIPIENT CONSIDERATIONS

Many patients with HCC listed for transplantation die from cancer progression while waiting for a deceased organ because of limited organ supply. This varies among jurisdictions but can be as high as 40% [5–7]. LDLT is, therefore, an attractive option to decrease waitlist times and theoretically limiting HCC progression. With advances in liver surgery and improvements in surgical technique, results after liver transplantation have progressively improved with excellent 1-year survival despite relatively high incidence of morbidity [8]. However, not all HCC patients should be transplanted, even with the availability of a living donor. The treatment decision depends on factors related to the patient and the tumour. The goal is to define transplant eligibility beyond the simple criteria of size and number of lesions, understand the biologic behaviour of the tumour, and identify patients with less aggressive tumours (irrespective of tumour burden) that will benefit most from LDLT.

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Benefits of living donor liver transplantation

Outcomes after LDLT versus DDLT have been extensively studied, with publications showing the absence of difference between treatments [5,9]. LDLT results are comparable with DDLT for both donation after circulatory death (DCD) and donation after brain death (DBD), as published by Kollmann et al.[10] that demonstrated similar 5-year overall patient survival of 71.6% for DCD, 83% for DBD, 88.8% for LDLT, and graft survival of 69.2% for DCD, 79.9% for DBD, and 84.7% for LDLT among 1054 patients from a single center (P = 0.14).

Specifically for HCC, the results of LDLT and DDLT have been compared in several studies as shown in Table 1[6,11,13]. Initially some of these studies showed higher recurrence in patients transplanted with living donor and investigators hypothesized that liver regeneration could be the reason for this finding [17,18]. However, these studies evaluated the outcomes after transplantation without an intention-to-treat (ITT) analysis (i.e. from the time of listing). In a recent meta-analysis by Zhu et al. of 29 studies with 5376 patients, they suggested that LDLT was not inferior to DDLT for perioperative and survival outcomes. However, in terms of 5-year ITT overall survival (OS), LDLT was a possibly better choice for HCC patients than DDLT [relative risk = 1.11, 95% confidence interval (CI) = 1.01–1.22, P = 0.04] [19]. Azoulay et al.[6] analyzed 861 patients listed for liver transplantation for HCC (79 LDLT and 782 DDLT) and found no difference in 5-year ITT-OS (73.2% for LDLT versus 66.7% for DDLT, P = 0.06) and no difference in recurrence rates (10.9% for LDLT versus 11.2% for DDLT, P = 0.75). Additionally, Bhangui et al.[20] found comparable recurrence and OS for DDLT and LDLT in an ITT analysis among a cohort of 183 HCC patients after liver transplantation. However, the mean wait list time was significantly less for the LDLT group (2.6 versus 7.9 months, P = 0.001).

Table 1

Table 1

Goldaracena et al.[14▪▪] published the benefit in terms of OS and disease-free survival for patients who had a potential donor for LDLT in an ITT analysis with a 5-year OS of 68% for LDLT versus 57% for DDLT (P = 0.02), reflecting a reduction in the dropout rate from 27.5% for DDLT versus 14.6% for LDLT (P < 0.001). Similarly, Wong et al.[16▪▪] described a survival benefit for LDLT in an ITT and propensity score matching analysis of 375 patients with 5-year OS of 81.4% for LDLT versus 40.8% for DDLT (P < 0.001). Table 2 summarizes different criteria utilized to select patients with HCC beyond Milan criteria for LDLT.

Table 2

Table 2

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Results of recipients beyond Milan criteria and how far we can go

In the last 2 years, centers have published their center-specific data in LDLT for HCC. In December 2017, Kyushu University published results of a prospective study using center-specific criteria, the Kyushu University criteria, largest tumour less than 5 cm or des-γ-carboxy prothrombin (DCP) level less than 300 mAU/ml without gross vascular invasion or extrahepatic metastasis on imaging studies, irrespective of the number of tumours [28]. Uchiyama et al.[28] published no significant difference in 5-year recurrence-free survival probabilities and 5-year overall patient survival of patients within-Milan and beyond-Milan patients meeting Kyushu criteria.

Shimamura et al.[29] performed a retrospective analysis of LDLT for HCC in Japan from 1998 to 2009 and based on their outcomes proposed a selection criteria for transplantation that achieved a 5-year survival rate over 70% and 5-year recurrence rate of less than 10%. They proposed the 5-5-500 rule: largest nodule size 5 cm or less in diameter, nodule number 5 or less, and alpha-fetoprotein (AFP) value 500 ng/ml or less as a new expanded criteria for LDLT for HCC and combined with Milan criteria (patients meeting either criteria) would increase patients with HCC eligible for transplantation by 19% [30].

In 2018, Pavel et al. published Barcelona's outcomes comparing recipients within Milan criteria and recipients fulfilling the Barcelona Clinic Liver Cancer (BCLC) Group expanded criteria, which is a single lesion 7 cm or less, up to three nodules 5 cm or less, or five nodules 3 cm or less [31,32]. Although small number of patients in each group (16 recipients within the Milan criteria and 26 in the BCLC expanded criteria) all received LDLT. There was no significant difference in 5-year and 10- year overall and disease-free survival between patients within Milan and those beyond Milan but within the BCLC expanded criteria [31]. Due to deceased organ donation scarcity in Asia, most centers perform mainly LDLT for HCC patients using varying criteria, but most beyond Milan. Yoon and Lee [33▪] recently reported the experience with LDLT for HCC in Asia demonstrating a 5-year overall survival ranging from 80 to 85.2%.

LDLT in patients with macrovascular invasion has gained interest. In a cohort of 282 patients, Lee et al. analyzed the outcomes of 11 patients with macrovascular invasion. The overall 5-year survival was 63.6% and 5-year disease-free survival was 45.5%. In the univariate survival analysis, the level of portal vein tumor thrombosis (PVTT) extending to the main portal vein was a significant factor for recurrence (P < 0.01). Although a very small number, the results challenge the current paradigm of macrovascular invasion being a contraindication to transplantation and the authors suggest that PVTT not extending into the main portal vein would be considered for curative intent treatment with LDLT [34]. This concept needs to be further explored in clinical trials.

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TUMOUR CONSIDERATIONS

Although some authors argue LDLT decreases HCC progression by decreasing wait time, others have shown that LDLT may increase recurrence rates and decrease cancer outcomes related to aggressive HCC that potentially would drop out waiting for a deceased organ. Some patients will have an unfavourable outcome regardless of the treatment received because of the individual characteristics of the tumour. In this case, liver transplantation would not be an effective treatment option and potentially preventing another patient from receiving a deceased organ or potentially undue harm to a living donor.

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Tumour characteristics

Tumour characteristics and evaluating tumour biology for predicting survival and posttransplant tumour recurrence in selecting patients who would benefit from transplant is not well known. Zhao et al.[35] showed a significant effect of tumour grade of differentiation on long-term prognosis of HCC after liver transplantation in a multivariable analysis of 802 Chinese patients with a hazard ratio of death of 2.62 for poorly differentiated tumours. These results justify the exclusion of such patients from liver transplantation, as used in the Extended Toronto criteria [36]. On the other hand, there is significant heterogeneity within a single HCC lesion with tumour structural variation within the same sample from a single needle biopsy, which suggests that preliver transplantation tumour histologic assessment may play a limited role in predicting tumour behaviour as the biopsy may not capture more aggressive tumour cells [37].

Efforts are focused on the identification of surrogates of tumour biology to define ways to predict results after liver transplantation for HCC. Among these strategies, response to bridging/downstaging therapies proved to be a potential predictor. As recently published by DiNorcia et al.[38▪], among 3439 HCC patients post liver transplantation, 802 patients with complete pathological response (cPR) after bridging therapies had a 5-year recurrence rate of only 5.2%, as compared with patients who do not achieve cPR (16.4%, P < 0.001). However, this study was based from the United States Multicenter HCC Transplant Consortium database and did not have granular data to assess stratification of the impact the specific percentage of tumour necrosis on outcomes, but only assessed the dichotomous cPR variable. Additionally, Doyle et al.[39] observed that outcomes of potentially transplantable patients undergoing ablation may vary significantly according to tumour size with patients with HCC larger than 2 cm and higher serum AFP being at greater risk of recurrence beyond transplant criteria. Also, liver transplantation was proven to be equally effective as salvage therapy for patients following ablation or surgery as primary treatment, expanding the indication of liver transplantation for HCC [40]. Conversely, response to locoregional therapy as a predictor of outcomes may be supplemented by response of serum AFP. Halazun et al.[41▪] found that among 1450 patients from three United States centers, the serum AFP response to treatment during the wait-list could predict posttransplantation outcomes and should be incorporated into HCC selection criteria to allow its expansion.

In a retrospective cohort of 455 patients listed for liver transplantation for HCC based on total tumour volume (TTV) 115 cm3 or less and AFP 400 ng/ml or less criteria, Toso et al. found that among patients downstaged to Milan, those originally beyond TTV115/AFP400 (n = 27) had similar outcomes as those originally beyond Milan but within TTV115/AFP400 (n = 53). However, the likelihood of being within Milan at transplant was lower for patients with more advanced initial HCC (P < 0.0001) [42]. Overall, despite an expected increase in posttransplant HCC recurrence, similar survivals could be achieved with and without downstaging even when including patients with advanced initial HCC, which reinforces the importance of treatment response as surrogate of tumour biology.

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Future prospects

Recent studies have identified new strategies of predicting tumour behaviour using a noninvasive technique. Radiomics is the process of converting medical images into high-dimensional, mineable data via high-throughput extraction of quantitative features, followed by subsequent data analysis. These radiomic features may be correlated with pathologic and genomics features, time to HCC recurrence, and survival by preliver transplantation image assessment. Zhou et al.[43] published the use of radiomics signature to predict early recurrence of HCC among 215 patients with a predictive area under the curve of 0.83 when combined with a clinical model. MacParland et al.[44] found an intrahepatic cellular immunologic heterogeneity using single-cell RNA that may point to understanding different tumour behaviour among patients. Finally, circulating tumour cells and cell-free DNA, also known as liquid biopsy, may be the key to understanding HCC tumour behaviour puzzle over the next few years [45,46]. Graf et al.[47] demonstrated with a national survey that pediatric transplant programs are already including genetic assessment of patients when evaluating for liver transplantation. All these advancements will likely play a role in selecting patients with HCC for LDLT beyond size and number of tumours.

Considering systemic therapies, sorafenib was the first drug approved for the treatment of HCC and is the standard of care when other treatments are not possible. Many agents tested in phase 3 trials failed to improve or even parallel the efficacy of sorafenib. Insufficient antitumoural activity, toxicity in the context of cirrhosis, and inadequate patient selection has been attributed to these failures. Sorafenib remained the sole systemic therapy until lenvatinib showed antitumoural activity in a noninferiority trial [48]. There is a positive trend in trials over recent years with an increasing optimism towards systemic treatment improvements for HCC. Induction therapy with these new drugs may be an alternative to test tumour responsiveness to treatment prior to LDLT. However, this needs to be investigated in prospective trials.

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DONOR SAFETY

Multiple studies have demonstrated the benefit of having a live donor for recipients with HCC with decreased waitlist times, decreased dropout rates, and improved overall survival for recipients with liver cancer [14▪▪,16▪▪,20]. The proportion of liver transplantation performed for HCC is increasing. For example, in Asia, the proportion of adult LDLT recipients with HCC has recently increased to 30–40%, and 90% of these transplants are LDLT [33▪]. Careful consideration is required whenever evaluating a patient for liver donation, given the potential harm and no physical benefit to the donor. LDLT is a well tolerated procedure for donors. Lee et al. analyzed the Korean Organ Transplant Registry of 832 LDLT donors over a period of 2 years and found an incidence of overall, biliary, and major complications of 9.3, 1.7 and 1.9%, respectively, and no deaths. Biliary complications were the most common types of major morbidity [49▪]. Gorgen et al. presented a postoperative mortality rate of 0% over 589 patients after donor right hepatectomy in a single center. After stratifying patients over time by eras based on the year in which the surgery was performed, the only predictor of postoperative complications was volume of donor hepatectomies in the previous 12 months, associating volume as a predictor of success [50▪].

Due to better results in surgical techniques and reconstructions, the risks to recipients has less of an impact on the decision to proceed with LDLT. But even after two decades of experience in complex laparoscopic hepatobiliary procedures, data on purely laparoscopic approach for donor hepatectomy in adult LDLT are limited. Shehta et al.[51] published in early 2019 of an expert consensus statement that laparoscopic adult living donor hepatectomy is considered in the development phase and not recommended for wide introduction at that time but shows promise application in the future.

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ETHICAL ASPECTS

Ethics surrounding LDLT for both the donor and recipient must be addressed balancing risk to the donor to recipient benefit. There are concerns regarding the validity of informed consent given by the donor. Organ trading is strictly prohibited, yet transplant tourism has flourished in some countries in spite of the existence of strict laws [52]. Although donations to nonrelative patients may initially seem to be altruistic, it is important to apply careful scrutiny.

Traditionally for DDLT based on Milan criteria, outcomes of 5-year OS greater than 70% and recurrence rate less than 10% are gold standards but these rates may not be attainable when transplanting patients with more advanced HCC. Given no data available, what is an acceptable 5-year OS and 5-year recurrence rate for HCC patients undergoing LDLT beyond Milan?

Additionally, ethical dilemmas arise when patients transplanted for HCC outside standard criteria who develop early graft loss or late graft complications after LDLT require re-transplantation. Re-transplanting with a deceased organ may prevent a patient meeting standard criteria from receiving a graft. Should patients with tumours outside standard criteria undergoing LDLT be prevented from receiving a deceased organ from the donor pool if they need re-transplantation emergently early postoperatively?

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CONCLUSION

Over the last 2 years, studies support a greater indication of LDLT for HCC beyond the standard Milan criteria with the development of new technologies that aid in predicting the long-term oncological outcomes with cautiously balancing the risks of harm to otherwise healthy donors. Expanding the indication for LDLT for HCC will provide a potential curable procedure to patients who otherwise have limited treatment options.

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Acknowledgements

None.

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Financial support and sponsorship

None.

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Conflicts of interest

There are no conflicts of interest.

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REFERENCES AND RECOMMENDED READING

Papers of particular interest, published within the annual period of review, have been highlighted as:

  • ▪ of special interest
  • ▪▪ of outstanding interest
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REFERENCES

1. Ferlay J, Soerjomataram I, Dikshit R, et al. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN. Int J Cancer 2015; 136:E359–E386.
2. Mazzaferro V, Llovet JM, Miceli R, et al. Metroticket Investigator Study GroupPredicting survival after liver transplantation in patients with hepatocellular carcinoma beyond the Milan criteria: a retrospective, exploratory analysis. Lancet Oncol 2009; 10:35–43.
3. Yao FY, Xiao L, Bass NM, et al. Liver transplantation for hepatocellular carcinoma: validation of the UCSF-expanded criteria based on preoperative imaging. Am J Transpl 2007; 7:2587–2596.
4. Sapisochin G, Goldaracena N, Laurence JM, et al. The extended Toronto criteria for liver transplantation in patients with hepatocellular carcinoma: A prospective validation study. Hepatology 2016; 64:2077–2088.
5. Ninomiya M, Shirabe K, Facciuto ME, et al. Comparative study of living and deceased donor liver transplantation as a treatment for hepatocellular carcinoma. J Am Coll Surg 2015; 220:297.e3–304.e3.
6. Azoulay D, Audureau E, Bhangui P, et al. Living or brain-dead donor liver transplantation for hepatocellular carcinoma: a multicenter, Western, intent-to-treat cohort study. Ann Surg 2017; 266:1035–1044.
7. Chen J, Xu X, Wu J, et al. The stratifying value of Hangzhou criteria in liver transplantation for hepatocellular carcinoma. PLoS One 2014; 9:e93128.
8. Majella MB, Majella MB, Muller X, et al. Defining benchmarks in liver transplantation: a multicenter outcome analysis determining best achievable results defining benchmarks in liver transplantation. Ann Surg 2018; 267:419–425.
9. Ogawa K, Takada Y. Living vs. deceased-donor liver transplantation for patients with hepatocellular carcinoma. Transl Gastroenterol Hepatol 2016; 1:35.
10. Kollmann D, Sapisochin G, et al. Expanding the donor pool: donation after circulatory death and living liver donation do not compromise the results of liver transplantation. Liver Transpl 2017; 24:779–789.
11. Lo CM, Fan ST, Liu CL, et al. Living donor versus deceased donor liver transplantation for early irresectable hepatocellular carcinoma. Br J Surg 2007; 94:78–86.
12. Lee SG, Hwang S, Moon DB, et al. Expanded indication criteria of living donor liver transplantation for hepatocellular carcinoma at one large-volume center. Liver Transpl 2008; 14:935–945.
13. Hu Z, Qian Z, Wu J, et al. Clinical outcomes and risk factors of hepatocellular carcinoma treated by liver transplantation: a multicentre comparison of living donor and deceased donor transplantation. Clin Res Hepatol Gastroenterol 2016; 40:315–326.
14▪▪. Goldaracena N, Gorgen A, Doyle A, et al. Live donor liver transplantation for patients with hepatocellular carcinoma offers increased survival vs. deceased donation. J Hepatol 2019; 70:666–673.

This is a large volume North American single-center intention-to-treat analysis of HCC patients postliver transplantation demonstrating survival benefit of LDLT when a living donor is available.

15. Goldaracena N, Barbas AS, Galante A, et al. Live donor liver transplantation with older donors: increased long-term graft loss due to HCV recurrence. Clin Transplant 2018; 32:e13304.
16▪▪. Wong TCL, Ng KKC, Fung JYY, et al. Long-term survival outcome between living donor and deceased donor liver transplant for hepatocellular carcinoma: intention-to-treat and propensity score matching analyses. Ann Surg Oncol 2019; 26:1454–1462.

This is a large volume Asian single center intention-to-treat analysis of HCC patients comparing LDLT to DDLT in a propensity score matching analysis showing the survival advantage of LDLT.

17. Park M-S, Lee K-W, Suh S-W, et al. Living-donor liver transplantation associated with higher incidence of hepatocellular carcinoma recurrence than deceased-donor liver transplantation. Transplantation 2014; 97:71–77.
18. Kulik LM, Fisher RA, Rodrigo DR, et al. A2ALL Study GroupOutcomes of living and deceased donor liver transplant recipients with hepatocellular carcinoma: results of the A2ALL cohort. Am J Transpl 2012; 12:2997–3007.
19. Zhu B, Wang J, Li H, et al. Living or deceased organ donors in liver transplantation for hepatocellular carcinoma: a systematic review and meta-analysis. Hpb 2019; 21:133–147.
20. Bhangui P, Vibert E, Majno P, et al. Intention-to-treat analysis of liver transplantation for hepatocellular carcinoma: living versus deceased donor transplantation. Hepatology 2011; 53:1570–1579.
21. Yao FY, Ferrell L, Bass NM, et al. Liver transplantation for hepatocellular carcinoma: expansion of the tumor size limits does not adversely impact survival. Hepatology 2001; 33:1394–1403.
22. Kaido T, Ogawa K, Mori A, et al. Usefulness of the Kyoto criteria as expanded selection criteria for liver transplantation for hepatocellular carcinoma. Surgery 2013; 154:1053–1060.
23. Kim JM, Kwon CHD, Joh J-W, et al. Expanded criteria for liver transplantation in patients with hepatocellular carcinoma. Transplant Proc 2014; 46:726–729.
24. Akamatsu N, Sugawara Y, Kokudo N. Living-donor vs deceased-donor liver transplantation for patients with hepatocellular carcinoma. World J Hepatol 2014; 6:626–631.
    25. Lee SD, Lee B, Kim SH, et al. Proposal of new expanded selection criteria using total tumor size and (18)F-fluorodeoxyglucose - positron emission tomography/computed tomography for living donor liver transplantation in patients with hepatocellular carcinoma: the National Cancer Center Korea criteria. World J Transplant 2016; 6:411–422.
      26. Uchiyama H, Itoh S, Yoshizumi T, et al. Living donor liver transplantation for hepatocellular carcinoma: results of prospective patient selection by Kyushu University Criteria in 7 years. HPB (Oxford) 2017; 19:1082–1090.
      27. Tan CHN, Yu Y, Tan YRN, et al. Bridging therapies to liver transplantation for hepatocellular carcinoma: a bridge to nowhere? Ann Hepato-Biliary-Pancreatic Surg 2018; 22:27–35.
        28. Uchiyama H, Itoh S, Yoshizumi T, et al. Living donor liver transplantation for hepatocellular carcinoma: results of prospective patient selection by Kyushu University Criteria in 7 years. Hpb 2017; 19:1082–1090.
        29. Shimamura T, Akamatsu N, Fujiyoshi M, et al. Expanded living-donor liver transplantation criteria for patients with hepatocellular carcinoma based on the Japanese nationwide survey: the 5-5-500 rule - a retrospective study. Transpl Int 2019; 32:356–368.
        30. Shimamura T, Akamatsu N, Fujiyoshi M, et al. Japanese Liver Transplantation SocietyExpanded living-donor liver transplantation criteria for patients with hepatocellular carcinoma based on the Japanese nationwide survey: the 5-5-500 rule - a retrospective study. Transpl Int 2019; 32:356–368.
        31. Pavel MC, Sanchez Cabus S, Crespo G, et al. Role of adult living donor liver transplantation in the treatment of hepatocellular carcinoma within and beyond milan criteria: a comparative study. Transplant Proc 2018; 50:1386–1395.
        32. Llovet JM, Pavel M, Rimola J, et al. Pilot study of living donor liver transplantation for patients with hepatocellular carcinoma exceeding Milan Criteria (Barcelona Clinic Liver Cancer extended criteria). Liver Transplant 2018; 24:369–379.
        33▪. Yoon Y-I, Lee S-G. Living donor liver transplantation for hepatocellular carcinoma: an Asian perspective. Dig Dis Sci 2019; 64:993–1000.

        This is a comparative review of outcomes after LDLT for HCC from different Asian centers with varying criteria.

        34. Lee K-W, Suh S-W, Choi Y, et al. Macrovascular invasion is not an absolute contraindication for living donor liver transplantation. Liver Transplant 2017; 23:19–27.
        35. Zhao J, Mao J, Li W. Association of tumor grade with long-term survival in patients with hepatocellular carcinoma after liver transplantation. Transplant Proc 2019; 51:813–819.
        36. Sapisochin G, Goldaracena N, Laurence JM, et al. The extended Toronto criteria for liver transplantation in patients with hepatocellular carcinoma: a prospective validation study. Hepatology 2016; 64:2077–2088.
        37. Ho DW, Tsui YM, Sze KM, et al. Single-cell transcriptomics reveals the landscape of intra-tumoral heterogeneity and stemness-related subpopulations in liver cancer. Cancer Lett 2019; 459:176–185.
        38▪. DiNorcia J, Florman SS, Haydel B, et al. Pathologic response to pretransplant locoregional therapy is predictive of patient outcome after liver transplantation for hepatocellular carcinoma. Ann Surg 2019; 1: doi: 10.1097/SLA.0000000000003253. [Epub ahead of print].

        The study analyzed HCC patients who achieved complete pathologic response after bridging therapies prior to liver transplantation and reinforces the importance of tumor biology rather than solely size and number for patient selection for liver transplantation.

        39. Doyle A, Gorgen A, Muaddi H, et al. Outcomes of radiofrequency ablation as first-line therapy for hepatocellular carcinoma less than 3 cm in potentially transplantable patients. J Hepatol 2019; 70:866–873.
        40. Muaddi H, Al-Adra DP, Beecroft R, et al. Liver transplantation is equally effective as a salvage therapy for patients with hepatocellular carcinoma recurrence following radiofrequency ablation or liver resection with curative intent. Ann Surg Oncol 2018; 25:991–999.
        41▪. Halazun KJ, Tabrizian P, Najjar M, et al. Is it time to abandon the Milan Criteria? Results of a bicoastal US collaboration to redefine hepatocellular carcinoma liver transplantation selection policies. Ann Surg 2018; 268:690–699.

        This is an important recent study with multicenter data from the United States evaluating the effect of response to bridging therapies by serum biomarkers and the importance of including in patient selection criteria.

        42. Toso C, Meeberg G, Andres A, et al. Downstaging prior to liver transplantation for hepatocellular carcinoma: advisable but at the price of an increased risk of cancer recurrence - a retrospective study. Transpl Int 2019; 32:163–172.
        43. Zhou Y, He L, Huang Y, et al. CT-based radiomics signature: a potential biomarker for preoperative prediction of early recurrence in hepatocellular carcinoma. Abdom Radiol 2017; 42:1695–1704.
        44. MacParland SA, Liu JC, Ma X-Z, et al. Single cell RNA sequencing of human liver reveals distinct intrahepatic macrophage populations. Nat Commun 2018; 9:4383.
        45. Wang S, Zheng Y, Liu J, et al. Analysis of circulating tumor cells in patients with hepatocellular carcinoma recurrence following liver transplantation. J Investig Med 2018; 66:1–6.
        46. Amado V, Rodríguez-Perálvarez M, Ferrín G, De la Mata M. Selecting patients with hepatocellular carcinoma for liver transplantation: incorporating tumor biology criteria. J Hepatocell Carcinoma 2018; 6:1–10.
        47. Graf M, Char D, Hanson-Kahn A, Magnus D. Use of genetic risks in pediatric organ transplantation listing decisions: a national survey. Pediatr Transplant 2019; 23:e13402.
        48. Villanueva A. Hepatocellular carcinoma. N Engl J Med 2019; 380:1450–1462.
        49▪. Lee JG, Lee K-W, Kwon CHD, et al. Donor safety in living donor liver transplantation: the Korean Organ Transplantation Registry Study. Liver Transplant 2017; 23:999–1006.

        In this national data analysis from South Korea, a large number of patients was analyzed to assess safety of living donor hepatectomy with discussion of technique and feasibility of LDLT.

        50▪. Gorgen A, Goldaracena N, Zhang W, et al. Surgical complications after right hepatectomy for live liver donation: largest single-center western world experience. Semin Liver Dis 2018; 38:134–144.

        This study demonstrates good outcomes of right donor hepatectomy in the largest Western living liver donor transplant program to date.

        51. Shehta A, Lee J, Lee K, et al. Pure laparoscopic living-donor hepatectomy for donors with right portal vein anatomical variations. Liver Transplant 2019; lt.25582: doi: 10.1002/lt.25582. [Epub ahead of print].
        52. Shazi L, Abbas Z. Ethical dilemmas related to living donor liver transplantation in Asia. Irish J Med Sci 2019; doi: 10.1007/s11845-019-01989-7. [Epub ahead of print].
        Keywords:

        hepatocellular carcinoma; living donor liver transplant; outcomes; survival; transplant criteria

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