Significance of preoperative fluorodeoxyglucose-positron emission tomography in prediction of tumor recurrence after liver transplantation for hepatocellular carcinoma patients: a Japanese multicenter study

Predictive Value of Preoperative 18 Fludeoxyglucose Positron Emission Tomography-Computed Tomography for Survival in Liver Transplantation Due to Hepatocellular Cancer

BACKGROUND

We aimed to study the predictive value of preoperative perform [18F] Fludeoxyglucose positron emission tomography-computed tomography ([18] FDG PET-CT) for survival in liver transplantation due to hepatocellular cancer.

METHODS

Ninety-six patients who underwent liver transplantation for hepatocellular cancer (HCC) after preoperative PET-CT evaluation were examined for the study. All patients' ages, genders, body mass index, blood groups, Child-Pugh and Model for End-Stage Liver Disease scores, etiologies, median Alpha Fetoprotein values, Milan Criteria and T stages, grades, macrovascular and microvascular invasions, multicentricities, maximum and total tumor sizes, tumor number findings in explant specimens, and recurrence rates were analyzed statistically.

RESULTS

Statistically, microvascular (P = .002) and macrovascular invasions (P = .034) were observed more frequently in patients who are PET-CT (+) compared with patients who are PET-CT (-). PET-CT positivity was associated with shortened disease-free survival (DFS) statistically (P = .004).

CONCLUSION

Positron emission tomography-CT positivity may be important for predicting prognostic markers such as DFS and vascular invasion in the preoperative evaluation. Before transplantation, PET-CT should be applied to all patients with HCC.

Impact of metabolic indices of 18F-fluorodeoxyglucose positron emission tomography/computed tomography on post transplantation recurrence of hepatocellular carcinoma

BACKGROUND

Tumor recurrence is the leading cause of death after liver transplantation in patients with hepatocellular carcinoma. There is an ongoing debate as to whether metabolic indices such as tumor to liver standardized uptake value ratio in ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography of the primary tumor can identify patients outside the Milan criteria with as low recurrence rates as patients inside Milan and thus should be added to the established prognostic factors.

METHODS

This retrospective study analyzes 103 consecutive patients who underwent ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography before liver transplantation for hepatocellular carcinoma using data of clinical tumor registry. Primary endpoints were overall survival and 10-year cumulative recurrence rates.

RESULTS

Tumor to liver standardized uptake value ratio of the primary tumor was statistically significant higher in Milan out tumors, "up-to-seven" out tumors, grade 3 tumors, α- fetoprotein level >400 ng/ml and lesions > 5cm in diameter. Factors with statistically significant influence on the 10- year overall survival in the univariate analysis were Milan, up-to-seven" criteria, number of lesions and pT-category. COX regression analysis did not show independently statistically significant factors for 10-year overall survival. Milan, "up-to-seven" criteria, grade, pV, number of lesions, size of lesion, pT-category, tumor to liver standardized uptake value ratio influenced 10-year cumulative recurrence rates statistically significant. Tumor to liver standardized uptake value ratio, grade and pT-category proved to be independently statistically significant factors for 10-year cumulative recurrence rates.

CONCLUSIONS

Our study suggests that tumor to liver standardized uptake value standardized uptake value ratio in ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography is an independent prognostic factor in transplanted patients with hepatocellular carcinoma. If we focus on preoperative findings, such as tumor size, tumor number and AFP value adding the information given by TLR of ¹⁸F-FDG PET/CT allows to estimate the risk of tumor recurrence more accurate than the established classifications Milan and UTS. Therefore, it may add valuable information to other preoperative findings, such as tumor size, tumor number and AFP level.

Predicting Overall Survival with Deep Learning from 18F-FDG PET-CT Images in Patients with Hepatocellular Carcinoma before Liver Transplantation

Positron emission tomography and computed tomography with 18F-fluorodeoxyglucose (18F-FDG PET-CT) were used to predict outcomes after liver transplantation in patients with hepatocellular carcinoma (HCC). However, few approaches for prediction based on 18F-FDG PET-CT images that leverage automatic liver segmentation and deep learning were proposed. This study evaluated the performance of deep learning from 18F-FDG PET-CT images to predict overall survival in HCC patients before liver transplantation (LT). We retrospectively included 304 patients with HCC who underwent 18F-FDG PET/CT before LT between January 2010 and December 2016. The hepatic areas of 273 of the patients were segmented by software, while the other 31 were delineated manually. We analyzed the predictive value of the deep learning model from both FDG PET/CT images and CT images alone. The results of the developed prognostic model were obtained by combining FDG PET-CT images and combining FDG CT images (0.807 AUC vs. 0.743 AUC). The model based on FDG PET-CT images achieved somewhat better sensitivity than the model based on CT images alone (0.571 SEN vs. 0.432 SEN). Automatic liver segmentation from 18F-FDG PET-CT images is feasible and can be utilized to train deep-learning models. The proposed predictive tool can effectively determine prognosis (i.e., overall survival) and, thereby, select an optimal candidate of LT for patients with HCC.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Prediction models of hepatocellular carcinoma recurrence after liver transplantation: A comprehensive review

Liver transplantation (LT) is one of the most effective treatments for hepatocellular carcinoma (HCC). Although LT eliminates HCC and greatly reduces recurrence, some patients experience recurrence after LT. Criteria and models for screening patients with a high probability of HCC recurrence after LT, starting with the Milan criteria, have been published. These models have changed over time, but a standard has not been established. We summarized HCC prediction models after LT by focusing on the application of radiologic, serologic, and pathologic factors and recent trends. This review will look at studies that are based on living donor LT and deceased donor LT, as well as studies that downstaging procedures have been performed preoperatively. This ultimately aims to help make decisions for evaluating the HCC state and selecting candidates for LT according to the circumstances of each transplantation center.

Current status of liver transplantation for non-B non-C liver cirrhosis and hepatocellular carcinoma

Recently, non-B non-C chronic liver diseases, including alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), have markedly increased worldwide. Liver transplantation (LT) is an effective curative therapy for hepatocellular carcinoma (HCC) as well as decompensated liver cirrhosis. In Japan, where the source of liver grafts is strongly dependent on living donors, efforts have been made to unify the indications for eligibility of HCC patients for LT, leading to the development of 5-5-500 criteria. Along with the expansion of eligibility for LT, the current changing trends in underlying liver diseases of LT recipients, which are related to the rising tide of non-B non-C cirrhosis and HCC, are highlighting the importance of peri-transplant management of patients with various comorbidities. The post-LT prognosis of patients with ALD is significantly affected by de novo malignancies and metabolic syndrome-related complications as well as posttransplant alcohol relapse. NAFLD/NASH patients often suffer from obesity, type 2 diabetes mellitus, and other metabolic syndrome-related disorders, and nonneoplastic factors such as cardiovascular events and recurrence of NAFLD/NASH have a significant impact on post-LT outcomes. Patient management in the peri-transplant period as well as risk assessment for LT are key to improving post-LT outcomes in the era of a growing number of cases of LT for non-B non-C liver diseases.

Patient Selection for Downstaging of Hepatocellular Carcinoma Prior to Liver Transplantation—Adjusting the Odds?

Background and Aims: Morphometric features such as the Milan criteria serve as standard criteria for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC). Since it has been recognized that these criteria are too restrictive and do not adequately display the tumor biology, additional selection parameters are emerging.

Methods: Concise review of the current literature on patient selection for downstaging and LT for HCC outside the Milan criteria.

Results: The major task in patients outside the Milan criteria is the need for higher granularity with patient selection, since the benefit through LT is not uniform. The recent literature clearly shows that beneath tumor size and number, additional selection parameters are useful in the process of patient selection for and during downstaging. For initial patient selection, the alpha fetoprotein (AFP) level adds additional information to the size and number of HCC nodules concerning the chance of successful downstaging and LT. This effect is quantifiable using newer selection tools like the WE (West-Eastern) downstaging criteria or the Metroticket 2.0 criteria. Also an initial PET-scan and/or tumor biopsy can be helpful, especially in the high risk group of patients outside the University of California San Francisco (UCSF) criteria. After this entry selection, the clinical course during downstaging procedures concerning the tumor and the AFP response is of paramount importance and serves as an additional final selection tool.

Conclusion: Selection criteria for liver transplantation in HCC patients are becoming more and more sophisticated, but are still imperfect. The implementation of molecular knowledge will hopefully support a more specific risk prediction for HCC patients in the future, but do not provide a profound basis for clinical decision-making at present.

Liver Transplantation for Hepatocellular Carcinoma: How Should We Improve the Thresholds?

Simple Summary

The ideal treatment for hepatocellular carcinoma (HCC) is liver transplantation (LT), which both eliminates the HCC and cures the diseased liver. Once considered an experimental treatment with dismal survival rates, LT for HCC entered a new era with the establishment of the Milan criteria over 20 years ago. However, over the last two decades, the Milan criteria, which are based on tumor morphology, have come under intense scrutiny and are now largely regarded as too restrictive, and limit the access of transplantation for many patients who would otherwise achieve good clinical outcomes. The liver transplant community has been making every effort to reach a goal of establishing more reliable selection criteria. This article addresses how the criteria have been extended, as well as the concept of pre-transplant down-staging to maximize the eligibility.

Abstract

Hepatocellular carcinoma (HCC) is the third highest cause of cancer-related mortality, and liver transplantation is the ideal treatment for this disease. The Milan criteria provided the opportunity for HCC patients to undergo LT with favorable outcomes and have been the international gold standard and benchmark. With the accumulation of data, however, the Milan criteria are not regarded as too restrictive. After the implementation of the Milan criteria, many extended criteria have been proposed, which increases the limitations regarding the morphological tumor burden, and incorporates the tumor’s biological behavior using surrogate markers. The paradigm for the patient selection for LT appears to be shifting from morphologic criteria to a combination of biologic, histologic, and morphologic criteria, and to the establishment of a model for predicting post-transplant recurrence and outcomes. This review article aims to characterize the various patient selection criteria for LT, with reference to several surrogate markers for the biological behavior of HCC (e.g., AFP, PIVKA-II, NLR, 18F-FDG PET/CT, liquid biopsy), and the response to locoregional therapy. Furthermore, the allocation rules in each country and the present evidence on the role of down-staging large tumors are addressed.

Clinical application of advances and innovation in radiation treatment of hepatocellular carcinoma

Background:

Hepatocellular carcinoma (HCC) management has evolved over the past two decades, with the development of newer treatment modalities. While various options are available, unmet needs are reflected through the mixed treatment outcome for intermediate-stage HCC. As HCC is radiosensitive, radiation therapies have a significant role in management. Radiation therapies offer local control for unresectable lesions and for patients who are not surgical candidates. Radiotherapy also provides palliation in metastatic disease, and acts as a bridge to resection and transplantation in selected patients. Advancements in radiotherapy modalities offer improved dose planning and targeted delivery, allowing for better tumor response and safer dose escalations while minimizing the risks of radiation-induced liver damage. Radiotherapy modalities are broadly classified into external beam radiation therapy and selective internal radiation therapy. With emerging modalities, radiotherapy plays a complementary role in the multidisciplinary care of HCC patients.

Aim:

We aim to provide an overview of the role and clinical application of radiation therapies in HCC management.

Relevance for Patients:

The continuous evolution of radiotherapy techniques allows for improved therapeutic outcomes while mitigating unwanted adverse effects, making it an attractive modality in HCC management. Rigorous clinical studies, quality research and comprehensive datasets will further its application in the present era of evidence-based practice in Medicine.

Liver Transplantation in Patients with Hepatocellular Carcinoma beyond the Milan Criteria: A Comprehensive Review

The Milan criteria (MC) were developed more than 20 years ago and are still considered the benchmark for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC). However, the strict application of MC might exclude some patients who may receive a clinical benefit of LT. Several expanded criteria have been proposed. Some of these consider pretransplant morphological and biological variables of the tumor, others consider post-LT variables such as the histology of the tumor, and others combine pre- and post-LT variables. More recently, the HCC response to locoregional treatments before transplantation emerged as a surrogate marker of the biological aggressiveness of the tumor to be used as a better selection criterion for LT in patients beyond the MC at presentation. This essential review aims to present the current data on the pretransplant selection criteria for LT in patients with HCC exceeding the MC at presentation based on morphological and histological characteristics of the tumor and to critically discuss those that have been validated in clinical practice. Moreover, the role of HCC biological markers and the tumor response to downstaging procedures as new tools for selecting patients with a tumor burden outside of the MC for LT is evaluated.

68Ga-PSMA PET/CT Versus 18F-FDG PET/CT for Imaging of Hepatocellular Carcinoma

Objectives:

This study aimed to compare the metabolic parameters obtained from ¹⁸fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) and gallium-68 (⁶⁸Ga)-prostate-specific membrane antigen (PSMA) PET/CT and investigate the relationship between serum alpha-fetoprotein and PET scan parameters in patients with hepatocellular carcinoma.

Methods:

Fourteen patients were recruited after dynamic magnetic resonance imaging (MRI) of the upper abdomen, and ¹⁸F-FDG and ⁶⁸Ga-PSMA PET/CT imaging studies were conducted. Regions of interest (ROIs) were drawn from lesion-free liver tissue, abdominal aorta (A), and right medial gluteal muscle (G) for the background activity. Maximum standard uptake value (SUV_max) of these regions were compared with the SUV_max of primary tumor (T).

Results:

On visual assessment, five patients (36%) experienced low ¹⁸F-FDG uptake in the primary lesion, three patients (21%) experienced moderate uptake, and six patients (43%) experienced high uptake. However, only one patient (7%) showed low ⁶⁸Ga-PSMA uptake, two patients (14%) showed moderate uptake, and 11 patients (79%) showed high uptake. Four patients with a low ¹⁸F-FDG uptake showed high ⁶⁸Ga-PSMA uptake, while one patient exhibited low uptake with both ¹⁸F-FDG and ⁶⁸Ga-PSMA. The number of lesions on ⁶⁸Ga-PSMA PET/CT and MRI was significantly higher than ¹⁸F-FDG PET/CT (p=0.042 and 0.026, respectively). T/A and T/G values were significantly higher in ⁶⁸Ga-PSMA than ¹⁸F-FDG (p=0.002 and 0.002, respectively).

Conclusion:

⁶⁸Ga-PSMA PET/CT is superior to ¹⁸F-FDG PET/CT in the staging of hepatocellular carcinoma. High ⁶⁸Ga-PSMA uptake could be promising for PSMA-targeted radionuclide treatments.

Investigating the value of pre-treatment 18F-FDG PET/CT in predicting the pathological characteristic of hepatocellular carcinoma and recurrence after liver transplantation

PURPOSE

The aim of this study is to investigate the value of pre-treatment ¹⁸F-FDG PET/CT in predicting the pathological characteristic of HCC and recurrence after liver transplantation (LT).

METHODS

A total of 34 patients who underwent ¹⁸F-FDG PET/CT before LT for HCC and did not receive any other treatment were retrospectively enrolled in the study. The maximal standard uptake value of the tumor (T-SUVmax), normal liver tissues (L-SUVmax), and mediastinal blood pool (B-SUVmax) were derived, followed by the calculations of the T-SUVmax/L-SUVmax (T/L) and the T-SUVmax/B-SUVmax (T/B) ratios. Combined with the post-transplantation pathological results and ROC curve, the performance in predicting the pathological characteristic and the recurrence after LT were evaluated.

RESULTS

The AUCs for T-SUVmax, T/L, and T/B in predicting the pathological grade of tumors were 0.820, 0.784, and 0.806, respectively. Alternatively, the AUCs for T-SUVmax, T/L, and T/B in predicting the recurrence after LT were 0.865, 0.899, and 0.931, respectively. The individual cutoff values were 5.0, 1.7, and 2.2, corresponding to a predication accuracy of 88.2%, 85.3%, and 88.2%, respectively. In addition, the AUCs for T/B in predicting microvascular invasion (mVI) and liver capsular invasion (LCI) were 0.825 and 0.788, respectively.

CONCLUSION

The pre-treatment ¹⁸F-FDG PET/CT is effective for predicting recurrence of HCC after LT. In addition, it demonstrates values for predicting the pathological characteristic of HCC such as pathological grade, mVI, and LCI.

An FDG PET/CT metabolic parameter-based nomogram for predicting the early recurrence of hepatocellular carcinoma after liver transplantation

PURPOSE

To construct an FDG PET/CT metabolic parameter-based model to predict early recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT).

METHODS

A total of 62 patients with HCC after LT were enrolled with a follow-up period of 1 year. Basic clinical, pathology, and laboratory data, CT features (CPLC), and PET metabolic parameters (CPLCP) were collected for model construction. A CPLC nomogram without metabolic parameters and a CPLCP nomogram with metabolic parameters were established. The net reclassification index (NRI) and integrated discrimination improvement (IDI) of the two models were calculated. The constructed model was compared with Milan criteria and University of California San Francisco (UCSF) criteria. The time-dependent area under the receiver operating characteristic curve (time-AUC) was used to compare the efficiency of the models, and the bootstrap method was used to for verification. Harrell's concordance index (C-index) was used to evaluate the performance of these models. Decision curve analysis (DCA) was used to evaluate the clinical practicability of each model.

RESULTS

Thirty out of 62 patients experienced a recurrence during the 1-year follow-up. BCLC stage (P = 0.009), MVI (P = 0.032), AFP (P = 0.004), CTdmax (P = 0.033), and MTV (P = 0.039) were the independent predictors. The CPLC nomogram and the CPLCP nomogram were established. Compared with the CPLC nomogram, the NRI of the CPLCP nomogram increased by 38.98% (95% CI = -18.77-60.43%) and the IDI increased by 4.40% (95% CI = -1.00-16.62%). The AUC value of the CPLCP nomogram was higher than those of Milan criteria and UCSF criteria in the time-AUC curve. Moreover, the CPLCP nomogram had a higher C-index (0.774) than other models. Finally, the DCA curve showed that clinical practicability of the CPLCP nomogram outperformed the Milan criteria and UCSF criteria.

CONCLUSIONS

The CPLCP nomogram combining basic clinical data, pathology data, laboratory data, CT features, and PET metabolic parameters showed good efficacy and high clinical practicability in predicting the early recurrence of HCC after LT.

Incorporating Tumor Biology to Predict Hepatocellular Carcinoma Recurrence in Patients Undergoing Living Donor Liver Transplantation Using Expanded Selection Criteria

Conventional selection criteria for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) are based on tumour size/number only, and do not consider vital surrogates of tumor biology such as alpha-fetoprotein (AFP) and tumor [¹⁸ F]fluorodeoxyglucose positron emission tomography ([¹⁸ F]FDG PET) avidity. We analyzed survival outcomes, and predictors of HCC recurrence in 405 patients with cirrhosis and HCC (HCC-cirr) who underwent living donor LT (LDLT) using our expanded selection criteria: no extrahepatic disease or major vascular invasion, irrespective of tumor size/number. Fifty-one percent patients had tumours beyond Milan, and 43% beyond the University of California San Francisco [UCSF] criteria. The 5-year overall survival (OS) and recurrence-free survival (RFS) were 64% and 70%, respectively. Three preoperatively available factors predicted recurrence: pre-LT AFP ≥100 ng/mL (P = 0.005; hazard ratio [HR], 2.190), tumor burden beyond the UCSF criteria (P = 0.001; HR, 2.640), and [¹⁸ F]FDG PET avidity (P = 0.004; HR, 2.442). A prognostic model based on the number and combination of the aforementioned preoperative risk factors was developed using a competing-risk RFS model. Three risk groups were identified: low (none or a single risk factor present, 9.3% recurrence), moderate (AFP ≥100 ng/mL and [¹⁸ F]FDG PET avidity, or beyond UCSF tumor and [¹⁸ F]FDG PET avidity, 25% recurrence), and high (AFP ≥100 ng/mL and beyond UCSF, or presence of all 3 risk factors, 46% recurrence). Acceptable long-term outcomes were achieved using our expanded selection criteria. Our prognostic model to predict recurrence based on preoperative biological and morphological factors could guide pretransplant management (downstaging versus upfront LDLT) with the aim of reducing post-LDLT recurrence.

The Real Impact of Bridging or Downstaging on Survival Outcomes after Liver Transplantation for Hepatocellular Carcinoma

INTRODUCTION

There is no consensus regarding selection criteria on liver transplantation (LT) for hepatocellular carcinoma (HCC), especially for living donor liver transplantation, although emerging evidence has been found for the effectiveness of bridging or downstaging.

OBJECTIVE

We evaluated the long-term outcomes of patients who underwent LT with or without bridging or downstaging for HCC.

METHODS

This retrospective study included 896 LT recipients with HCC between June 2005 and May 2015. Recurrence-free survival (RFS), overall survival (OS), and their associated factors were evaluated.

RESULTS

The 5-year RFS in the full cohort of 896 patients was 82.4%, and the OS was 85.3%. In patients with initial Organ Procurement and Transplantation Network (OPTN) T1 and T2, the 5-year RFS and OS did not significantly differ between LT groups with and without bridging (all p ≥ 0.05). The 5-year RFS and OS of OPTN T3 patients with successful downstaging were not significantly different from those of patients with OPTN T2 with primary LT (p = 0.070 and p = 0.185), but were significantly higher than in patients with OPTN T3 with downstaging failure and initial OPTN T1 or T2 with progression (all p < 0.001). In the multivariate analysis, last alpha-fetoprotein before LT ≥70 ng/mL (hazard ratio [HR]: 1.77, p = 0.001; HR: 1.72, p = 0.004), pretransplant HCC status exceeding the Milan criteria (HR: 5.12, p < 0.001; HR: 3.31, p < 0.001), and positron emission tomography positivity (HR: 2.57, p < 0.001; HR: 2.57, p < 0.001) were independent predictors for worse RFS and OS.

CONCLUSIONS

The impact of bridging therapy on survival outcomes is limited in patients with early-stage HCC, whereas OPTN T1 or T2 with progression provides worse prognosis. OPTN T3 should undergo LT after successful downstaging, and OPTN T3 with successful downstaging allows for acceptable long-term posttransplant outcomes.

Four gene intrahepatic metastasis-risk signature predicts hepatocellular carcinoma malignant potential and early recurrence from intrahepatic metastasis

BACKGROUND

Hepatocellular carcinoma has a high recurrence rate even after curative surgery, and hepatocellular carcinoma risk-predictive biomarkers will enable identification of patients who most need close monitoring and cancer-preventive intervention. Hepatocellular carcinoma has 2 different recurrence patterns-a multicentric recurrence and an intrahepatic metastasis. We have reported that the molecular gene signature from the gene expression of adjacent liver can be used to predict multicentric recurrence of hepatocellular carcinoma, but the signature to predict recurrence from intrahepatic metastasis has not been established. We aimed to identify the recurrence from intrahepatic metastasis gene signature from the gene expression of tumor to predict recurrence from intrahepatic metastasis.

METHODS

The intrahepatic metastasis-risk signature was created based on the exhaustive analysis using a microarray transcriptome database of hepatocellular carcinoma. The intrahepatic metastasis-risk signature was measured in a cohort of 80 hepatocellular carcinoma patients, and the correlation with hepatocellular carcinoma recurrence and overall survival and each gene signature were analyzed and validated.

RESULTS

The gene signature assay classified the patients into high- (n = 20), intermediate- (n = 40), and low-risk (n = 20) groups. The high-risk prediction was independently associated with higher early hepatocellular carcinoma recurrence (hazard ratio = 3.7, P = .03) in multivariable modeling adjusted by tumor size, tumor number, and microvascular invasion. Gene set enrichment analysis demonstrates that the gene sets associated with "cell cycle" or "histone modulation" are highly enriched in the high intrahepatic metastasis gene signature group CONCLUSION: The intrahepatic metastasis gene signature predicts early recurrence and is associated with malignant potential related to the promoted cell cycle.

Positron-emission tomography for hepatocellular carcinoma: Current status and future prospects

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality worldwide. Various imaging modalities provide important information about HCC for its clinical management. Since positron-emission tomography (PET) or PET-computed tomography was introduced to the oncologic setting, it has played crucial roles in detecting, distinguishing, accurately staging, and evaluating local, residual, and recurrent HCC. PET imaging visualizes tissue metabolic information that is closely associated with treatment. Dynamic PET imaging and dual-tracer have emerged as complementary techniques that aid in various aspects of HCC diagnosis. The advent of new radiotracers and the development of immuno-PET and PET-magnetic resonance imaging have improved the ability to detect lesions and have made great progress in treatment surveillance. The current PET diagnostic capabilities for HCC and the supplementary techniques are reviewed herein.

Hepatocellular carcinoma recurrence after liver transplantation: Risk factors, screening and clinical presentation

Liver transplantation is the best treatment option for cirrhotic patients with early-stage hepatocellular carcinoma, but it faces the problem of scarcity of donors and the risk of tumor recurrence, which affects between 15% and 20% of the cases, despite the use of restrictive criteria. The risk of recurrence depends on a number of factors, related to the tumor, the patient, and the treatment, which are discussed in this review. Some of these factors are already well established, such as the histopathological characteristics of the tumor, Alpha-fetoprotein (AFP) levels, and waiting time. Other factors related to the biological behavior of the tumor and treatment should be recognized because they can be used in the refinement of the selection criteria of transplant candidates and in an attempt to reduce recurrence. This review also discusses the clinical presentation of recurrence and its prognosis, contributing to the identification of a subgroup of patients who may have better survival, if they are timely identified and treated. Development of recurrence after the first year, with AFP levels ≤ 100 ng/mL, and single site capable of locoregional therapy are associated with better survival after recurrence.

Emerging role of 18F-fluorodeoxyglucose positron emission tomography for guiding management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of major causes of cancer mortality worldwide. For decades, ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been widely used for staging, predicting prognosis, and detecting cancer recurrence in various types of malignant diseases. Due to low sensitivity of FDG PET for detecting intrahepatic HCC lesions, the clinical value of FDG PET in HCC patients has been limited. However, recent studies with diverse analytic methods have shown that FDG PET has promising role in aiding management of HCC patients. In this review, we will discuss the clinical role of FDG PET for staging, predicting prognosis, and evaluating treatment response in HCC. Further, we will focus on recent clinical studies regarding implication of volumetric FDG PET parameters, the significance of FDG uptake in HCC for selecting treatment and predicting treatment response, and the use of radiomics of FDG PET in HCC.

18F-fludeoxyglucose positron emission tomography for diagnosis of HCC: implications for therapeutic strategy in curative and non-curative approaches

Hepatocellular carcinoma (HCC) is a global health issue with increasing incidence and high mortality rate. Depending on the tumor load and extent of underlying liver cirrhosis, aggressive surgical treatment by hepatectomy or liver transplantation (LT) may lead to cure, whereas different modalities of liver-directed locoregional or systemic tumor treatments are currently available for a noncurative approach. Apart from tumor burden and grade of liver dysfunction, assessment of prognostic relevant biological tumor aggressiveness is vitally important for establishing a promising multimodal therapeutic strategy and improving the individual treatment-related risk/benefit ratio. In recent years, an increasing body of clinical evidence has been presented that ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET), which is a standard nuclear imaging device in oncology, may serve as a powerful surrogate for tumor invasiveness and prognosis in HCC patients and, thereby, impact individual decision making on most appropriate therapy concept. This review describes the currently available data on the prognostic value of ¹⁸F-FDG PET in patients with early and advanced HCC stages and the resulting implications for treatment strategy.

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

Expansion of the liver transplantation indication criteria for patients with hepatocellular carcinoma (HCC) has long been debated. Here we propose new, expanded living-donor liver transplantation (LDLT) criteria for HCC patients based on a retrospective data analysis of the Japanese nationwide survey. A total of 965 HCC patients undergoing LDLT were included, 301 (31%) of whom were beyond the Milan criteria. Here, we applied the Greenwood formula to investigate new criteria enabling the maximal enrollment of candidates while securing a 5-year recurrence rate (95% upper confidence limit) below 10% by examining various combinations of tumor numbers and serum alpha-fetoprotein values, and maintaining the maximal nodule diameter at 5 cm. Finally, new expanded criteria for LDLT candidates with HCC, the 5-5-500 rule (nodule size ≤5 cm in diameter, nodule number ≤5, and alfa-fetoprotein value ≤500 ng/ml), were established as a new regulation with a 95% confidence interval of a 5-year recurrence rate of 7.3% (5.2-9.3) and a 19% increase in the number of eligible patients. In addition, the 5-5-500 rule could identify patients at high risk of recurrence, among those within and beyond the Milan criteria. In conclusion, the new criteria - the 5-5-500 rule - might provide rational expansion for LDLT candidates with HCC.

Role of pre-transplant 18F-FDG PET/CT in predicting hepatocellular carcinoma recurrence after liver transplantation

The last two decades have seen a paradigm shift in the selection of patients with hepatocellular carcinoma (HCC) for liver transplantation. Microvascular invasion and differentiation have been the most significant factors affecting post-transplant recurrence; however, because of inherent disadvantages of pre-transplant biopsy, histological criteria never gained popularity. Recently, the selection criteria evolved from morphological to biological criteria, such as biomarkers and response to loco-regional therapy. With the introduction of multimodality imaging, combination of computed tomography with nuclear medicine imaging, particularly, 18F-fluorodeoxyglucose positron emission tomography fulfilled an unmet need and rapidly became a critical component of HCC management. This review article will focus on the use of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography in the pre-transplant evaluation of HCC patients with special discussion on its ability to predict HCC recurrence after liver transplantation.

Evolutionary Distance Predicts Recurrence After Liver Transplantation in Multifocal Hepatocellular Carcinoma

Background

Liver transplantation (LTx) is a potentially curative treatment option for hepatocellular carcinoma (HCC) in cirrhosis. However, patients, where HCC is already a systemic disease, LTx may be individually harmful and has a negative impact on donor organ usage. Thus, there is a need for improved selection criteria beyond nodule morphology to select patients with a favorable outcome for LTx in multifocal HCC. Evolutionary distance measured from genome-wide single-nucleotide polymorphism data between tumor nodules and the cirrhotic liver may be a prognostic marker of survival after LTx for multifocal HCC.

Methods

In a retrospective multicenter study, clinical data and formalin-fixed paraffin-embedded specimens of the liver and 2 tumor nodules were obtained from explants of 30 patients in the discovery and 180 patients in the replication cohort. DNA was extracted from formalin-fixed paraffin-embedded specimens followed by genome wide single-nucleotide polymorphism genotyping.

Results

Genotype quality criteria allowed for analysis of 8 patients in the discovery and 17 patients in the replication set. DNA concentrations of a total of 25 patients fulfilled the quality criteria and were included in the analysis. Both, in the discovery (P = 0.04) and in the replication data sets (P = 0.01), evolutionary distance was associated with the risk of recurrence of HCC after transplantation (combined P = 0.0002). In a univariate analysis, evolutionary distance (P = 7.4 × 10⁻⁶) and microvascular invasion (P = 1.31 × 10⁻⁵) were significantly associated with survival in a Cox regression analysis.

Conclusions

Evolutionary distance allows for the determination of a high-risk group of recurrence if preoperative liver biopsy is considered.

The authors of this multicenter retrospective study assess whether the evolutionary distance measured from genome-wide single nucleotide polymorphism (SNP) data between tumor nodules and the cirrhotic liver may be a prognostic marker of survival after liver transplantation for multifocal hepatocellular carcinoma. Supplemental digital content is available in the text.

Combining 18F-FDG positron emission tomography with Up-to-seven criteria for selecting suitable liver transplant patients with advanced hepatocellular carcinoma

The Up-to-seven (UTS) criteria (sum of tumor size and number not exceeding 7) for indicating liver transplantation (LT) in hepatocellular carcinoma (HCC) were originally based on explant pathology features and absence of microvascular invasion (MVI). ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) was shown to indicate the risk of MVI and tumor recurrence. The aim of this study was to analyze the prognostic significance of the clinical UTS criteria when being combined with PET-status of the tumor. Data of 116 liver transplant patients were subject to retrospective analysis. Five-year recurrence-free survival (RFS) rates in patients meeting (n = 85) and exceeding (n = 21) the radiographic UTS criteria were 81% and 55.1%, respectively (p = 0.014). In the UTS In subset, RFS was significantly better in PET-negative (94.9%) than in PET-positive patients (48.3%; p < 0.001). In the UTS Out subset, 5-year RFS rates were 87.1% and 19% in patients with non- ¹⁸F-FDG-avid and ¹⁸F-FDG-avid tumors (p < 0.001), respectively. Positive PET-status was identified as the only independent clinical predictor of tumor recurrence in beyond UTS patients (Hazard ratio [HR] 19.25; p < 0.001). Combining radiographic UTS criteria with FDG-PET may safely expand the HCC selection criteria for LT.

18F-FDG-PET for Assessing Biological Viability and Prognosis in Liver Transplant Patients with Hepatocellular Carcinoma

Liver transplantation (LT) has become standard of care in patients with non-resectable early stage hepatocellular carcinoma (HCC) in liver cirrhosis. Currently, patient selection for LT is strictly based on tumor size and number, provided by the Milan criteria. This may, however, exclude patients with advanced tumor load but favourable biology from a possibly curative treatment option. It became clear in recent years that biological tumor viability rather than tumor macromorphology determines posttransplant outcome. In particular, microvascular invasion and poor grading reflect tumor aggressiveness and promote the risk of tumor relapse. Pretransplant biopsy is not applicable due to tumor heterogeneity and risk of tumor cell seeding. ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET), an established nuclear imaging device in oncology, was demonstrated to non-invasively correlate with unfavorable histopathologic features. Currently, there is an increasing amount of evidence that ¹⁸F-FDG-PET is very useful for identifying eligible liver transplant patients with HCC beyond standard criteria but less aggressive tumor properties. In order to safely expand the HCC selection criteria and the pool of eligible liver recipients, tumor evaluation with ¹⁸F-FDG-PET should be implemented in pretransplant decision process.

Liver transplantation for intermediate hepatocellular carcinoma: An adaptive approach

Hepatocellular carcinoma is becoming an increasing indication for liver transplantation, but selection and allocation of patients are challenging because of organ shortages. Conventional Milan criteria are the reference for the selection of patients worldwide, but many expanded criteria, like University of California San Francisco criteria and up-to-7 criteria, have demonstrated that survival and recurrence results are lower than those for restricted indications. Correct staging is crucial and should include surrogate markers of biological aggressiveness (α-fetoprotein, response to loco-regional treatments). Successful down-staging can select between patients with tumor burden initially beyond transplantation criteria those with a more favorable biology, provided a 3-mo stability in meeting the transplantation criteria. Allocation rules are constantly adjusted to minimize the imbalance between the priorities of candidates with and without hepatocellular carcinoma, and take into account local donor rate and waitlist dynamics. Recently, Mazzaferro et al proposed a benefit-oriented “adaptive approach”, in which the selection and allocation of patients are based on their response to non-transplantation treatments: low priority for transplantation in case of complete response, high priority in case of partial response or recurrence, and no listing in case of progression beyond transplantation criteria.