When to call it off: defining transplant candidacy limits in liver donor liver transplantation for hepatocellular carcinoma

Poorly differentiated hepatocellular carcinoma: resection is equivalent to transplantation in patients with low liver fibrosis

BACKGROUND

Organ allocation criteria for liver transplantation focus on tumor size and multifocality while tumor differentiation and existing liver damage are omitted. This study analyzes the impact of hepatocellular carcinoma (HCC) grade and liver fibrosis comparing resection (SX) to transplantation (LT).

METHODS

The National Cancer Database was queried between 2004 and 2016 for solitary HCC meeting Milan criteria undergoing SX vs LT. Two groups were created: low fibrosis (LF) vs high fibrosis (HF) and stratified by grade. Cox multivariable regression models, Kaplan-Meier survival analyses and log-rank tests were performed.

RESULTS

1515 patients were identified; 780 had LT and 735 had SX. Median overall survival (mOS) was 39.7 months; LT mOS was 47.9 months vs SX mOS of 34.9 months (P < .001). Multivariate analysis revealed SX, no chemotherapy, longer hospital stays, and age to be associated with worse survival. However, while transplantation conferred survival benefit for well-moderately differentiated tumors, SX vs LT did not impact survival for poorly differentiated HCC in LF patients, independent of tumor size.

DISCUSSION

HCC differentiation and liver fibrosis, but not size, synergistically determine efficacy of SX vs LT. Therefore, current HCC transplantation criteria should incorporate tumor grade or liver fibrosis for optimal organ allocation.

Liver transplantation for hepatocellular carcinoma: Improving eligibility without compromising outcomes

Background

In the context of liver transplantation for hepatocellular carcinoma (HCC), traditional transplant criteria appear restrictive. The objective of the current study was to determine risk factors for recurrence and improve transplant eligibility in patients with HCC.

Materials and methods

This was a retrospective study of patients who underwent living donor liver transplant (LDLT) for HCC (n = 219). Largest tumor diameter, tumor number, AFP and neutrophil to lymphocyte ratio were assessed. Multivariate analysis was performed to develop risk scores. The new model was compared with seven previously published transplant criteria using receiver operator curves.

Results

Largest tumor size >3.7 cm [HR:2.6, P = 0.02], and AFP > 600 ng/ml [HR:4.7, P = 0.001] were independent predictors of recurrence. Patients with risk scores of 0, 1–3, 4–6 and 7–9 had recurrence rate of 5.9%, 12.5%, 25% and 58.4% respectively. When compared with Milan criteria, Metro ticket 2.0, AFP model and Samsung criteria; transplant eligibility increased by 31.5%, 22.9%, 8.7%, and 7% respectively. Recurrence rate with the current model was 16/199 (8%) (P < 0.0001) and was comparable with other transplant criteria (6.9–9.1%). On ROC analysis, only Milan criteria (AUC = 0.7, P = 0.001) and the current model (AUC = 0.66, P = 0.01) showed significance for recurrence. All patients with high risk scores within Milan criteria had recurred at 3 years (P = 0.03).

Conclusions

Low AFP can be used to select patients for LDLT outside traditional criteria for HCC, with comparable recurrence rates.

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There is an unmet need to expand transplant pool for hepatocellular carcinoma.

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We developed a model, based on tumor size cutoff of 3.7 cm, any tumor number, and AFP cutoff of 600 ng/ml; and compared it with other transplant criteria.

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There was considerable expansion in transplant pool with comparable outcomes.

Living donor liver transplantation for advanced hepatocellular carcinoma including macrovascular invasion

Background

The indications for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) continue to evolve. The aim of this study was to report outcomes in patients who underwent living donor liver transplantation (LDLT) for HCC outside traditional criteria including macrovascular invasion (MVI).

Methods

We reviewed outcomes in patients who met the University of California San Francisco (UCSF) criteria (n = 159) and our center-specific criteria (UCSF+) (largest tumor diameter ≤ 10 cm, any tumor number, AFP ≤ 1000 ng/ml) (n = 58). We also assessed outcomes in patients with MVI (n = 27).

Results

The median follow was 28 (10.6–42.7) months. The 5 year overall survival and risk of recurrence (RR) in the UCSF and UCSF + group was 71% vs 69% (P = 0.7) and 13% vs 36% (P = 0.1) respectively. When patients with AFP > 600 ng/ml were excluded from the UCSF + group, RR was 27% (P = 0.3). Among patients with MVI who had downstaging (DS), 4/5(80%) in low-risk group (good response and AFP ≤ 100 ng/ml) and 2/10 (20%) in the high-risk group (poor response or AFP > 100 ng/ml) were alive at the last follow-up. When DS was not feasible, 3/3 (100%) in the low-risk group (AFP ≤ 100 ng/ml + Vp1-2 MVI) and 1/9 (9.1%) in the high-risk group (AFP > 100 or Vp3 MVI) were alive. The 5 year OS in the low-risk MVI group was 85% (P = 0.003).

Conclusion

With inclusion of AFP, response to downstaging and degree of MVI, acceptable survival can be achieved with LDLT for HCC outside traditional criteria.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03665-9.

Revisiting Surgical Strategies for Hepatocellular Carcinoma With Microvascular Invasion

Although liver resection (LR) and liver transplantation (LT) are widely considered as potentially curative therapies for selected patients with hepatocellular carcinoma (HCC); however, there is still high risk of tumor recurrence in majority of HCC patients. Previous studies demonstrated that the presence of microvascular invasion (MVI), which was defined as the presence of tumor emboli within the vessels adjacent to HCC, was one of the key factors of early HCC recurrence and poor surgical outcomes after LR or LT. In this review, we evaluated the impact of current MVI status on surgical outcomes after curative therapies and aimed to explore the surgical strategies for HCC based on different MVI status with evidence from pathological examination. Surgical outcomes of HCC patients with MVI have been described as a varied range after curative therapies due to a broad spectrum of current definitions for MVI. Therefore, an international consensus on the validated definition of MVI in HCC is urgently needed to provide a more consistent evaluation and reliable prediction of surgical outcomes for HCC patients after curative treatments. We concluded that MVI should be further sub-classified into MI (microvessel invasion) and MPVI (microscopic portal vein invasion); for HCC patients with MPVI, local R0 resection with a narrow or wide surgical margin will get the same surgical results. However, for HCC patients with MI, local surgical resection with a wide and negative surgical margin will get better surgical outcomes. Nowadays, MVI status can only be reliably confirmed by histopathologic evaluation of surgical specimens, limiting its clinical application. Taken together, preoperative assessment of MVI is of utmost significance for selecting a reasonable surgical modality and greatly improving the surgical outcomes of HCC patients, especially in those with liver cirrhosis.

Clinical value of artificial intelligence in hepatocellular carcinoma: Current status and prospect

Hepatocellular carcinoma (HCC) is the most commonly diagnosed type of liver cancer and the fourth leading cause of cancer-related mortality worldwide. The early identification of HCC and effective treatments for it have been challenging. Due to the sufficient compensatory ability of early patients and its nonspecific symptoms, HCC is more likely to escape diagnosis in the incipient stage, during which patients can achieve a more satisfying overall survival if they undergo resection or liver transplantation. Patients at advanced stages can profit from radical therapies in a limited way. In order to improve the unfavorable prognosis of HCC, diagnostic ability and treatment efficiency must be improved. The past decade has seen rapid advancements in artificial intelligence, underlying its unique usefulness in almost every field, including that of medicine. Herein, we sought and reviewed studies that put emphasis on artificial intelligence and HCC.

Living Donor Liver Transplantation for Hepatocellular Carcinoma: Appraisal of the United Network for Organ Sharing Modified TNM Staging

Background: In deceased donor liver transplantation (DDLT), transplant eligibility for T3–T4 HCC requires successful downstaging (DS). Living donor liver transplantation (LDLT) can be considered selectively in these patients without DS, but its role is not defined. The objective of the current study was to assess outcomes of LDLT for HCC based on UNOS staging with no prior DS.

Materials and Methods: Patients who underwent LDLT for HCC (n = 262) were staged based on modified UNOS TNM staging. High-risk factors were identified and 5-year recurrence free survival was compared in patients with T2–T4 HCC.

Results: Median follow-up was 30.2 (16.4–46.3) months. Recurrence rate in T1, T2, T3, T4a, and T4b HCC was 0, 10.1, 16.1, 5.9, and 37.5% (P = 0.02), respectively. On multivariate analysis, AFP > 600 ng/mL [HR:11.7, P < 0.001] and T4b HCC (macrovascular invasion) [HR = 5.6, P = 0.03] were predictors of recurrence. After exclusion of AFP > 600 ng/mL, 5-year RFS for T2, T3, and T4a HCC was 94, 86, and 92% (P = 0.3). Rate of microvascular invasion between T2 and T3 HCC was 24.3 vs. 53.6% (P = 0.005), and between T2 and T4a HCC was 24.3 vs. 36.7% (P = 0.2). Overall, 26 (19.4%) patients were overstaged and 23 (17.1%) were understaged on preoperative imaging. The 5-year RFS in patients with identical preoperative and histopathological staging was 94, 87, and 94% (P = 0.6).

Conclusion: LDLT without prior DS leads to comparable survival for UNOS T2, T3, and T4a HCC as long as AFP is < 600 ng/mL.

Risk Score Model for Liver Transplant Outcomes after Preoperative Locoregional Therapy for Hepatocellular Carcinoma

PURPOSE

The role of preoperative locoregional therapy (LRT) for hepatocellular carcinoma (HCC) before liver transplantation (LT) remains unclear. Moreover, LRT in the setting of living donor liver transplantation (LDLT) merits further exploration. The objective of the current study was to determine risk factors for poor outcomes after LDLT in patients who received locoregional therapy (LRT).

METHODS

We reviewed patients (n = 46) who underwent LDLT after LRT. Multivariate analysis was performed to determine independent predictors of recurrence-free survival (RFS). Risk scores were developed to define prognostic groups.

RESULTS

Median tumor size was 3.7 (1.2-12) cm and tumor number was 1 (1-6). Macrovascular invasion was seen in 10/46 (21.7%) patients. There was a significant difference in 5-year RFS with > 3 tumor nodules (P = 0.005), tumors outside University of California San Francisco criteria (P = 0.03), bilobar disease (P = 0.002), AFP > 600 ng/ml (P = 0.006), and poor response to LRT (P = 0.007). On multivariate analysis, bilobar disease (HR = 2.9, P = 0.01), AFP > 600 ng/ml (HR = 2.3 P = 0.008), and poor response to LRT (HR = 2, P = 0.02) were predictors of 5-year RFS. The 5-year RFS in low risk (score = 0), intermediate risk (score = 1-3), and high risk (score = 4-7) groups was 86%, 76%, and 9% (P < 0.0001). There was no recurrence seen in 4/4 (100%) patients with macrovascular invasion in the low-intermediate risk group. The 5-year RFS in the low-intermediate risk group within and outside Milan criteria was 100% and 74% (P = 0.1).

CONCLUSIONS

LDLT can provide excellent long-term RFS in patients after preoperative LRT in the low and intermediate risk groups.