Surveillance for HCC After Liver Transplantation: Increased Monitoring May Yield Aggressive Treatment Options and Improved Postrecurrence Survival

SIMAP500: A novel risk score to identify recipients at higher risk of hepatocellular carcinoma recurrence following liver transplantation

BACKGROUND

Recurrence of hepatocellular carcinoma (HCC) following liver transplantation (LT) has a devastating influence on recipients’ survival; however, the risk of recurrence is not routinely stratified. Risk stratification is vital with a long LT waiting time, as that could influence the recurrence despite strict listing criteria.

AIM

This study aims to identify predictors of recurrence and develop a novel risk prediction score to forecast HCC recurrence following LT.

METHODS

A retrospective review of LT for HCC recipients at University Hospitals Birmingham between July 2011 and February 2020. Univariate and multivariate analyses were performed to identify recurrence predictors, based on which the novel SIMAP500 (satellite nodules, increase in size, microvascular invasion, AFP > 500, poor differentiation) risk score was proposed.

RESULTS

234 LTs for HCC were performed with a median follow-up of 5.3 years. Recurrence developed in 25 patients (10.7%). On univariate analyses, RETREAT score > 3, α-fetoprotein (AFP) at listing 100-500 and > 500, bridging, increased tumour size between imaging at the listing time and explant histology, increase in the size of viable tumour between listing and explant, presence of satellite nodules, micro- and macrovascular invasion on explant and poor differentiation of tumours were significantly associated with recurrence, based on which, the SIMAP500 risk score is proposed. The SIMAP500 demonstrated an excellent predictive ability (c-index = 0.803) and outperformed the RETREAT score (c-index = 0.73). SIMAP500 is indicative of the time to disease recurrence.

CONCLUSION

SIMAP500 risk score identifies the LT recipients at risk of HCC recurrence. Risk stratification allows patient-centric post-transplant surveillance programs. Further validation of the score is recommended.

Delayed brain metastasis in recurrent hepatocellular carcinoma following liver transplantation: a case report highlighting the predictive value of microvascular invasion

Recurrent hepatocellular carcinoma (HCC) poses a significant challenge after liver transplantation, affecting approximately 10-23% of patients with a median onset of 13 months post-transplantation. Extrahepatic involvement, such as lung, bone, adrenal glands, peritoneum, lymph nodes, and central nervous system (CNS), is commonly observed among transplant recipients with HCC recurrence. Notably, vascular invasion (VI), including microvascular invasion (MiVI) and macrovascular invasion (MVI), substantially increase the risk of recurrence by 2.42- and 7.82-fold, respectively. This article presents a unique case of a 72-year-old male patient with a history of HCV-related cirrhosis and HCC who underwent orthotopic liver transplantation (OLT). Six years later, he presented to the emergency department following a fall, which led to the discovery of a pathologic fracture of T7 and an incidental intracranial mass during imaging. Subsequent biopsy confirmed metastatic HCC in the T7 lesion, while magnetic resonance imaging revealed two enhancing brain masses. One mass measured 4.8 cm in the left occipitotemporal lobe, and the other measured 1.7 cm in the right frontal gyrus. Notably, the patient had exhibited MiVI and a mildly elevated alpha-fetoprotein level (AFP) of 7.6 ng/mL at the time of his OLT. This case underscores the predictive value of MiVI in HCC recurrence post-OLT. Accordingly, extended post-transplantation surveillance is crucial for patients with HCC and MiVI. Moreover, this report highlights the uncommon occurrence of delayed brain metastasis following OLT in a patient with HCC.

Post-transplant inflammatory cytokine signature adds value for predicting tumor recurrence after liver transplantation for hepatocellular carcinoma

BACKGROUND

Cytokines are key regulators of post-transplant inflammation responses which reconstitute post-transplant hepatic and systemic environments to influence the likelihood of tumor relapse. This study investigated the prognostic value of post-transplant cytokines on tumor recurrence after liver transplantation (LT) for hepatocellular carcinoma (HCC).

METHODS

A retrospective analysis was conducted in prospectively collected 150 adult HCC patients who received liver transplantation from 1997 to 2015. The post-transplant 41 inflammatory cytokines were quantified by multiplexing analysis and determined their prognostic value for predicting post-LT tumor recurrence by receiver operative characteristic analysis. A prediction model for post-LT tumor recurrence was generated by the logistic regression and internally validated Bootstrapping and compared with external prediction models.

RESULTS

Post-transplant circulating CCL11, IFNα2, and IL17A cytokines were identified to be significant predictors of post-LT tumor recurrence and survival. A prediction score composed of the post-transplant 3-cytokine (P3C) signature, UCSF criteria, and pre-LT AFP was established. The P3C-UCSF-AFP score significantly predicted post-LT tumor recurrence and poor survival both in deceased donor liver transplantation (DDLT) and living donor liver transplantation (LDLT). The P3C-UCSF-AFP score was validated to significantly predict post-LT 2-year and 5-year tumor recurrence, outperforming the RETREAT score, French AFP model, up-to-seven, UCSF criteria, and Milan criteria. Importantly, the P3C-UCSF-AFP score could cost-effectively stratify high-risk recipients subjected to a refinement of post-recurrence survival.

CONCLUSION

The integrated P3C-UCSF-AFP score not only compensated for the pre-LT unpredictability and predicted post-LT tumor recurrence accurately, but also guided the clinical refinements of post-LT surveillance and therapeutic strategies in transplant oncology.

Development and validation of a REcurrent Liver cAncer Prediction ScorE (RELAPSE) following liver transplantation in patients with hepatocellular carcinoma: Analysis of the US Multicenter HCC Transplant Consortium

HCC recurrence following liver transplantation (LT) is highly morbid and occurs despite strict patient selection criteria. Individualized prediction of post-LT HCC recurrence risk remains an important need. Clinico-radiologic and pathologic data of 4981 patients with HCC undergoing LT from the US Multicenter HCC Transplant Consortium (UMHTC) were analyzed to develop a REcurrent Liver cAncer Prediction ScorE (RELAPSE). Multivariable Fine and Gray competing risk analysis and machine learning algorithms (Random Survival Forest and Classification and Regression Tree models) identified variables to model HCC recurrence. RELAPSE was externally validated in 1160 HCC LT recipients from the European Hepatocellular Cancer Liver Transplant study group. Of 4981 UMHTC patients with HCC undergoing LT, 71.9% were within Milan criteria, 16.1% were initially beyond Milan criteria with 9.4% downstaged before LT, and 12.0% had incidental HCC on explant pathology. Overall and recurrence-free survival at 1, 3, and 5 years was 89.7%, 78.6%, and 69.8% and 86.8%, 74.9%, and 66.7%, respectively, with a 5-year incidence of HCC recurrence of 12.5% (median 16 months) and non-HCC mortality of 20.8%. A multivariable model identified maximum alpha-fetoprotein (HR = 1.35 per-log SD, 95% CI,1.22-1.50, p < 0.001), neutrophil-lymphocyte ratio (HR = 1.16 per-log SD, 95% CI,1.04-1.28, p < 0.006), pathologic maximum tumor diameter (HR = 1.53 per-log SD, 95% CI, 1.35-1.73, p < 0.001), microvascular (HR = 2.37, 95%-CI, 1.87-2.99, p < 0.001) and macrovascular (HR = 3.38, 95% CI, 2.41-4.75, p < 0.001) invasion, and tumor differentiation (moderate HR = 1.75, 95% CI, 1.29-2.37, p < 0.001; poor HR = 2.62, 95% CI, 1.54-3.32, p < 0.001) as independent variables predicting post-LT HCC recurrence (C-statistic = 0.78). Machine learning algorithms incorporating additional covariates improved prediction of recurrence (Random Survival Forest C-statistic = 0.81). Despite significant differences in European Hepatocellular Cancer Liver Transplant recipient radiologic, treatment, and pathologic characteristics, external validation of RELAPSE demonstrated consistent 2- and 5-year recurrence risk discrimination (AUCs 0.77 and 0.75, respectively). We developed and externally validated a RELAPSE score that accurately discriminates post-LT HCC recurrence risk and may allow for individualized post-LT surveillance, immunosuppression modification, and selection of high-risk patients for adjuvant therapies.

Cell-Free DNA as a Surveillance Tool for Hepatocellular Carcinoma Patients after Liver Transplant

The liver is the world's sixth most common primary tumor site, responsible for approximately 5% of all cancers and over 8% of cancer-related deaths. Hepatocellular carcinoma (HCC) is the predominant type of liver cancer, accounting for approximately 75% of all primary liver tumors. A major therapeutic tool for this disease is liver transplantation. Two of the most significant issues in treating HCC are tumor recurrence and graft rejection. Currently, the detection and monitoring of HCC recurrence and graft rejection mainly consist of imaging methods, tissue biopsies, and alpha-fetoprotein (AFP) follow-up. However, they have limited accuracy and precision. One of the many possible components of cfDNA is circulating tumor DNA (ctDNA), which is cfDNA derived from tumor cells. Another important component in transplantation is donor-derived cfDNA (dd-cfDNA), derived from donor tissue. All the components of cfDNA can be analyzed in blood samples as liquid biopsies. These can play a role in determining prognosis, tumor recurrence, and graft rejection, assisting in an overall manner in clinical decision-making in the treatment of HCC.

Screening, Surveillance, and Management of Hepatocellular Carcinoma During the COVID-19 Pandemic: a Narrative Review

PURPOSE

The COVID-19 pandemic has been a burden to the global community as a whole but the healthcare community had bore the brunt of it. The pandemic resulted in policy changes that interfered with effective healthcare delivery. The healthcare community attempted to cope with the pandemic by triaging and prioritizing emergency conditions especially COVID related, ahead of elective conditions like cancer care. There was also fear that patients with cancer were at an increased risk of sever COVID-19 with increased mortality. Hepatocellular carcinoma (HCC) was also affected by these policies.

METHODS

We reviewed the modified measures adopted in screening, surveillance, and management of HCC during the pandemic using PubMed, Medline, Index Medicus, EMBASE, SCOPUS, and Google Scholar databases.

RESULT

The main modification in surveillance and screening for HCC during the pandemic includes limiting the surveillance to those with very high risk of HCC. The interval between surveillan was also delayed by few months in some cases. The adoption of teleconferencing for multidisciplinary team meetings and patient consultation is one of the highlights of this pandemic all in an effort to reduce contact and spread of the virus. The treatment of early-stage HCC was also modified as needed. The role of ablative therapy in the management of early HCC was very prominent during the pandemic as the surgical therapy was significantly affected by the lacks of ventilators and intensive care unit space resulting from the pandemic. Transplantation, especially living donor liver transplantation, was suspended in few centers because of the risk of infection to the living donors.

CONCLUSION

As we gradually recover from the pandemic, we should prepare for the fallout from the pandemic as we may encounter increased presentation of those patients deferred from screening during the pandemic.

Resected Tumor Outcome and Recurrence (RESTORE) Index for Hepatocellular Carcinoma Recurrence after Resection

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the fourth most common cause of cancer-related death worldwide [...].

Main factors influencing long-term outcomes of liver transplantation in 2022

Liver transplant (LT) outcomes have markedly improved in the recent decades, even if long-term morbidity and mortality are still considerable. Most of late deaths are independent from graft function and different comorbidities, including complications of metabolic syndrome and de novo neoplasms, seem to play a key role in determining long-term outcomes in LT recipients. This review discusses the main factors associated with late mortality and suggests possible strategies to improve long-term management and follow-up after liver transplantation. In particular, the reduction of drug toxicity, the use of tools to identify high-risk patients, and setting up a multidisciplinary team also for long-term management of LT recipients may further improve survival after liver transplantation.

Posttransplant Hepatocellular Carcinoma Surveillance: A Cost-effectiveness and Cost-utility Analysis

OBJECTIVE

Assess cost-effectiveness and -utility associated with posttransplant HCC surveillance compared to standard follow-up.

SUMMARY OF BACKGROUND DATA

Despite lack of prospective clinical data, expert consensus recommends posttransplant surveillance to detect HCC recurrence in a latent phase, while it might be amenable to curative-intent therapy.

METHODS

A Markov-based transition model was created to estimate life expectancy and quality-of-life among liver transplant patients undergoing HCC surveillance. Models were built for 2 cohorts: 1 undergoing HCC surveillance with contrast-enhanced computed tomography of chest and abdomen and serum alpha-fetoprotein analysis and the other receiving standard posttransplant follow-up. Primary model outputs included LY and QALY gains, incremental cost-effectiveness ratio, and incremental cost-utility ratio. Willingness-to-pay for a QALY gain (cost-effectiveness threshold) was used to estimate efficiency.

RESULTS

Surveillance was marginally more effective versus no surveillance, resulting in means of 0.069 LYs and 0.026 QALYs gained. Costs for surveillance were increased by an average of 988.32€, resulting in incremental cost-effectiveness ratio 14,410.15€/LY and incremental cost-utility ratio 37,547.97€/QALY. Surveillance did not seem cost-effective in our setting, considering willingness-to-pay threshold of 25,000€/QALY. Probabilistic sensitivity analysis indicated surveillance might be cost-effective in 42% of cases, but degree of uncertainty in the analysis was high.

CONCLUSIONS

Performing posttransplant HCC surveillance offers marginal clinical benefits and increases costs. Although expert consensus supports surveillance, results of this decision analysis raise doubt regarding the utility of such recommendations and support ongoing need for prospective clinical trials.

Machine Learning Models for Prediction of Posttreatment Recurrence in Early-Stage Hepatocellular Carcinoma Using Pretreatment Clinical and MRI Features: A Proof-of-Concept Study

BACKGROUND. Posttreatment recurrence is an unpredictable complication after liver transplant for hepatocellular carcinoma (HCC) that is associated with poor survival. Biomarkers are needed to estimate recurrence risk before organ allocation. OBJECTIVE. This proof-of-concept study evaluated the use of machine learning (ML) to predict recurrence from pretreatment laboratory, clinical, and MRI data in patients with early-stage HCC initially eligible for liver transplant. METHODS. This retrospective study included 120 patients (88 men, 32 women; median age, 60.0 years) with early-stage HCC diagnosed who were initially eligible for liver transplant and underwent treatment by transplant, resection, or thermal ablation between June 2005 and March 2018. Patients underwent pretreatment MRI and posttreatment imaging surveillance. Imaging features were extracted from postcontrast phases of pretreatment MRI examinations using a pretrained convolutional neural network. Pretreatment clinical characteristics (including laboratory data) and extracted imaging features were integrated to develop three ML models (clinical model, imaging model, combined model) for predicting recurrence within six time frames ranging from 1 through 6 years after treatment. Kaplan-Meier analysis with time to recurrence as the endpoint was used to assess the clinical relevance of model predictions. RESULTS. Tumor recurred in 44 of 120 (36.7%) patients during follow-up. The three models predicted recurrence with AUCs across the six time frames of 0.60-0.78 (clinical model), 0.71-0.85 (imaging model), and 0.62-0.86 (combined model). The mean AUC was higher for the imaging model than the clinical model (0.76 vs 0.68, respectively; p = .03), but the mean AUC was not significantly different between the clinical and combined models or between the imaging and combined models (p > .05). Kaplan-Meier curves were significantly different between patients predicted to be at low risk and those predicted to be at high risk by all three models for the 2-, 3-, 4-, 5-, and 6-year time frames (p < .05). CONCLUSION. The findings suggest that ML-based models can predict recurrence before therapy allocation in patients with early-stage HCC initially eligible for liver transplant. Adding MRI data as model input improved predictive performance over clinical parameters alone. The combined model did not surpass the imaging model's performance. CLINICAL IMPACT. ML-based models applied to currently underutilized imaging features may help design more reliable criteria for organ allocation and liver transplant eligibility.

Antitumor Effect of Low-Dose of Rapamycin in a Transgenic Mouse Model of Liver Cancer

PURPOSE

We investigate whether low-dose rapamycin is effective in preventing hepatocellular carcinoma (HCC) growth and treating HCC after tumor development in transgenic mice.

MATERIALS AND METHODS

We established transgenic mice with HCC induced by activated HrasG12V and p53 suppression. Transgenic mice were randomly assigned to five experimental groups: negative control, positive control, tacrolimus only, rapamycin only, and tacrolimus plus rapamycin. The mice were further divided into two groups according to time to commencement of immunosuppressant treatment: de novo treatment and post-tumor development.

RESULTS

In the de novo treatment group, marked suppression of tumor growth was observed in the rapamycin only group. In the post-tumor development group, the rapamycin only group displayed no significant suppression of tumor growth, compared to the positive control group. In T lymphocyte subset analysis, the numbers of CD4⁺ effector T cells and CD4⁺ regulatory T cells were significantly lower in the positive control, tacrolimus only, and tacrolimus plus rapamycin groups than the negative control group. Immunohistochemical analysis revealed significantly higher expression of phosphorylated-mTOR, 4E-BP1, and S6K1 in the positive control group than in the rapamycin only group.

CONCLUSION

Low-dose rapamycin might be effective to prevent HCC growth, but may be ineffective as a treatment option after HCC development.

Association between vessels that encapsulate tumour clusters vascular pattern and hepatocellular carcinoma recurrence following liver transplantation

BACKGROUND

Vessels that encapsulate tumor clusters (VETC) is a novel vascular pattern seen on hepatocellular carcinoma (HCC) histology which has been shown to independently predict tumor recurrence and survival after liver resection. Its prognostic value in HCC patients receiving liver transplantation (LT) is unclear.

METHODS

We retrospectively studied consecutive adults who underwent deceased-donor LT with active HCC found on explant between 2010-2019. Tumor tissue was stained for CD34 and quantified for VETC. Primary and secondary endpoints were time to recurrence (TTR) and recurrence-free survival (RFS).

RESULTS

During the study period, 158 patients received LT where HCC was present on explant. VETC pattern was seen in 76.5% of explants. Patients with VETC-positive tumors spent longer on the waitlist (6.4 vs. 4.1 months, P=0.048), had higher median tumor numbers (2 vs. 1, P=0.001) and larger tumor sizes (20mm vs. 13mm, P<0.001) on explant pathology compared to those with VETC-negative tumors. Correspondingly, VETC-positive patients were more likely to be outside of accepted LT criteria for HCC. After 56.4 months median follow-up, 8.2% of patients developed HCC recurrence post-LT. On multivariable Cox regression, presence of VETC pattern did not predict TTR or RFS. However, the number of VETC-positive tumors on explant was an independent predictor of TTR (hazard ratio [HR] 1.411, P=0.001) and RFS (HR 1.267, P=0.014) after adjusting for other significant variables.

CONCLUSION

VETC pattern is commonly observed in HCC patients undergoing LT. The number of VETC-positive tumors, but not its presence, is an independent risk factor for TTR and RFS post-LT.

Delayed Hepatocellular Carcinoma Recurrence After Liver Transplantation: Comprehensive Clinical Characterization of Case Series

Purpose

Liver transplantation (LT) is the definite curative treatment for hepatocellular carcinoma (HCC), but recurrence can occur even under stringent criteria. “Delayed” HCC recurrence (>3 years after LT) is not common. Here, we present the clinical features of patients who developed delayed HCC recurrence after LT.

Patients and Methods

We reviewed the data of eligible patients from February 1999 to December 2020 from medical records.

Results

From among 195 (17%) HCC patients who received LT, 34 experienced HCC recurrence, with 5 (15%) delayed recurrence. These five explant tumors were staged T1b–T2, graded II–III, with two vascular invasion and four beyond the Milan criteria. The median time to recurrence was 6.1 years, with the longest interval being nearly 18 years. Recurrence patterns included two extrahepatic, one intrahepatic, and two mixed extrahepatic and intrahepatic recurrences. A drastic increase in serum alpha-fetoprotein levels was observed in four cases 1 year before recurrence. Management of recurrence included locoregional (surgssical resection in three, radiotherapy in three, transarterial chemoembolization in one, radiofrequency ablation in one) and systemic sorafenib use in three. Two patients died within 12–18 months, one died within 18–24 months, and two are still alive until the end of the study, with respective 13.5- and 16.5-month survival.

Conclusion

Delayed HCC recurrence could occur over 10 years. Therefore, continual surveillance for recurrence is justified, but biomarkers and intervals or intensities specific for delayed recurrence are not validated, which warrants further validation to facilitate personalized medical care.

Therapeutic strategies for post-transplant recurrence of hepatocellular carcinoma

Despite stringent selection criteria, hepatocellular carcinoma recurrence after liver transplantation (LT) still occurs in up to 20% of cases, mostly within the first 2–3 years. No adjuvant treatments to prevent such an occurrence have been developed so far. However, a balanced use of immunosuppression with minimal dose of calcineurin inhibitors and possible addition of mammalian target of rapamycin inhibitors is strongly advisable. Moreover, several pre- and post-transplant predictors of recurrence have been identified and may help determine the frequency and duration of post-transplant follow-up. When recurrence occurs, the outcomes are poor with a median survival of 12 mo according to most retrospective studies. The factor that most impacts survival after recurrence is timing (within 1–2 years from LT according to different authors). Several therapeutic options may be chosen in case of recurrence, according to timing and disease presentation. Surgical treatment seems to provide a survival benefit, especially in case of late recurrence, while the benefit of locoregional treatments has been suggested only in small retrospective studies. When systemic treatment is indicated, sorafenib has been proved safe and effective, while only few data are available for lenvatinib and regorafenib in second line. The use of immune checkpoint inhibitors is controversial in this setting, given the safety warnings for the risk of acute rejection.

Different Models to Predict the Risk of Recurrent Hepatocellular Carcinoma in the Setting of Liver Transplantation

Simple Summary

Liver transplantation is considered the first-choice curative therapy for hepatocellular carcinoma in the early phase of the disease, when surgical resection is not possible. Even when implementing restrictive criteria to select patients for liver transplantation, there is a risk of recurrence in the transplanted liver, influencing the long-term outcome and prognosis. As it is challenging to predict the individual risk of recurrence, there is a need for validated and predictive scoring systems to use to stratify patients before and/or after liver transplantation. Most of the proposed scorings include biological markers for tumour behavior, in addition to the number and size of tumoral nodules. In this review, we discuss different published models to assess the risk of recurrent hepatocellular carcinoma after transplantation. Our aim is to refine clinical decisions about prioritization and listing for liver transplantation, to better inform patients and provide an appropriate surveillance strategy to influence their prognosis.

Abstract

Liver transplantation is the preferred therapeutic option for non-resectable hepatocellular carcinoma in early-stage disease. Taking into account the limited number of donor organs, liver transplantation is restricted to candidates with long-term outcomes comparable to benign indications on the waiting list. Introducing the morphometric Milan criteria as the gold standard for transplant eligibility reduced the recurrence rate. Even with strict patient selection, there is a risk of recurrence of between 8 and 20% in the transplanted liver, and this is of even greater importance when using more expanded criteria and downstaging protocols. Currently, it remains challenging to predict the risk of recurrence and the related prognosis for individual patients. In this review, the recurrence-risk-assessment scores proposed in the literature are discussed. Currently there is no consensus on the optimal model or the implications of risk stratification in clinical practice. The most recent scorings include additional biological markers for tumour behavior, such as alfa-foetoprotein, and the response to locoregional therapies, in addition to the number and diameter of tumoral nodules. The refinement of the prediction of recurrence is important to better inform patients, guide decisions about prioritization and listing and implement individualized surveillance strategies. In the future, this might also provide indications for tailored immunosuppressive therapy or inclusion in trials for adjuvant treatment.

Liver transplantation for patients with hepatocellular carcinoma: Its current status and advances

Liver transplantation is one of the best treatment options for selected patients with hepatocellular carcinoma (HCC). The Milan criteria (a single tumor with a maximum size of 5 cm or two or three tumors with a maximum size of 3 cm without evidence of vascular or extrahepatic involvement or metastasis) are one of the most common criteria to select patients with HCC for transplantation, though they are considered too restrictive. A moderate expansion of the criteria has been found to yield comparable recurrence-free survival rates. HCC will recur in approximately 10% of patients, and mostly within the first 2 years after transplantation. The preoperative level of alpha-fetoprotein, macrovascular invasion, tumor size, and tumor number are prognostic factors for recurrence. Recurrence of HCC after transplantation results in a poor prognosis.

Prognostic Factors for 10-Year Survival in Patients With Hepatocellular Cancer Receiving Liver Transplantation

Background

Long-term survival after liver transplantation (LT) for hepatocellular cancer (HCC) continues to increase along with the modification of inclusion criteria. This study aimed at identifying risk factors for 5- and 10-year overall and HCC-specific death after LT.

Methods

A total of 1,854 HCC transplant recipients from 10 European centers during the period 1987-2015 were analyzed. The population was divided in three eras, defined by landmark changes in HCC transplantability indications. Multivariable logistic regression analyses were used to evaluate the significance of independent risk factors for survival.

Results

Five- and 10-year overall survival (OS) rates were 68.1% and 54.4%, respectively. Two-hundred forty-two patients (13.1%) had HCC recurrence. Five- and 10-year recurrence rates were 16.2% and 20.3%. HCC-related deaths peaked at 2 years after LT (51.1% of all HCC-related deaths) and decreased to a high 30.8% in the interval of 6 to 10 years after LT. The risk factors for 10-year OS were macrovascular invasion (OR = 2.71; P = 0.001), poor grading (OR = 1.56; P = 0.001), HCV status (OR = 1.39; P = 0.001), diameter of the target lesion (OR = 1.09; P = 0.001), AFP slope (OR = 1.63; P = 0.006), and patient age (OR = 0.99; P = 0.01). The risk factor for 10-year HCC-related death were AFP slope (OR = 4.95; P < 0.0001), microvascular (OR = 2.13; P < 0.0001) and macrovascular invasion (OR = 2.32; P = 0.01), poor tumor grading (OR = 1.95; P = 0.001), total number of neo-adjuvant therapies (OR = 1.11; P = 0.001), diameter of the target lesion (OR = 1.11; P = 0.002), and patient age (OR = 0.97; P = 0.001). When analyzing survival rates in function of LT era, a progressive improvement of the results was observed, with patients transplanted during the period 2007-2015 showing 5- and 10-year death rates of 26.8% and 38.9% (vs. 1987-1996, P < 0.0001; vs. 1997-2006, P = 0.005).

Conclusions

LT generates long-term overall and disease-free survival rates superior to all other oncologic treatments of HCC. The role of LT in the modern treatment of HCC becomes even more valued when the follow-up period reaches at least 10 years. The results of LT continue to improve even when prudently widening the inclusion criteria for transplantation. Despite the incidence of HCC recurrence is highest during the first 5 years post-transplant, one-third of them occur later, indicating the importance of a life-long follow-up of these patients.

Scoring systems for the management of oncological hepato-pancreato-biliary patients

Oncological scoring systems in surgery are used as evidence-based decision aids to best support management through assessing prognosis, effectiveness and recurrence. Currently, the use of scoring systems in the hepato-pancreato-biliary (HPB) field is limited as concerns over precision and applicability prevent their widespread clinical implementation. The aim of this review was to discuss clinically useful oncological scoring systems for surgical management of HPB patients. A narrative review was conducted to appraise oncological HPB scoring systems. Original research articles of established and novel scoring systems were searched using Google Scholar, PubMed, Cochrane, and Ovid Medline. Selected models were determined by authors. This review discusses nine scoring systems in cancers of the liver (CLIP, BCLC, ALBI Grade, RETREAT, Fong's score), pancreas (Genç's score, mGPS), and biliary tract (TMHSS, MEGNA). Eight models used exclusively objective measurements to compute their scores while one used a mixture of both subjective and objective inputs. Seven models evaluated their scoring performance in external populations, with reported discriminatory c-statistic ranging from 0.58 to 0.82. Selection of model variables was most frequently determined using a combination of univariate and multivariate analysis. Calibration, another determinant of model accuracy, was poorly reported amongst nine scoring systems. A diverse range of HPB surgical scoring systems may facilitate evidence-based decisions on patient management and treatment. Future scoring systems need to be developed using heterogenous patient cohorts with improved stratification, with future trends integrating machine learning and genetics to improve outcome prediction.

R3-AFP score is a new composite tool to refine prediction of hepatocellular carcinoma recurrence after liver transplantation

Background & Aims

Patients with hepatocellular carcinoma (HCC) are selected for liver transplantation (LT) based on pre-LT imaging ± alpha-foetoprotein (AFP) level, but discrepancies between pre-LT tumour assessment and explant are frequent. Our aim was to design an explant-based recurrence risk reassessment score to refine prediction of recurrence after LT and provide a framework to guide post-LT management.

Methods

Adult patients who underwent transplantation between 2000 and 2018 for HCC in 47 centres were included. A prediction model for recurrence was developed using competing-risk regression analysis in a European training cohort (TC; n = 1,359) and tested in a Latin American validation cohort (VC; n=1,085).

Results

In the TC, 76.4% of patients with HCC met the Milan criteria, and 89.9% had an AFP score of ≤2 points. The recurrence risk reassessment (R3)-AFP model was designed based on variables independently associated with recurrence in the TC (with associated weights): ≥4 nodules (sub-distribution of hazard ratio [SHR] = 1.88, 1 point), size of largest nodule (3–6 cm: SHR = 1.83, 1 point; >6 cm: SHR = 5.82, 5 points), presence of microvascular invasion (MVI; SHR = 2.69, 2 points), nuclear grade >II (SHR = 1.20, 1 point), and last pre-LT AFP value (101–1,000 ng/ml: SHR = 1.57, 1 point; >1,000 ng/ml: SHR = 2.83, 2 points). Wolber’s c-index was 0.76 (95% CI 0.72–0.80), significantly superior to an R3 model without AFP (0.75; 95% CI 0.72–0.79; p = 0.01). Four 5-year recurrence risk categories were identified: very low (score = 0; 5.5%), low (1–2 points; 15.1%), high (3–6 points; 39.1%), and very high (>6 points; 73.9%). The R3-AFP score performed well in the VC (Wolber’s c-index of 0.78; 95% CI 0.73–0.83).

Conclusions

The R3 score including the last pre-LT AFP value (R3-AFP score) provides a user-friendly, standardised framework to design post-LT surveillance strategies, protocols, or adjuvant therapy trials for HCC not limited to the Milan criteria.

Clinical Trials Registration

NCT03775863.

Lay summary

Considering discrepancies between pre-LT tumour assessment and explant are frequent, reassessing the risk of recurrence after LT is critical to further refine the management of patients with HCC. In a large and international cohort of patients who underwent transplantation for HCC, we designed and validated the R3-AFP model based on variables independently associated with recurrence post-LT (number of nodules, size of largest nodule, presence of MVI, nuclear grade, and last pre-LT AFP value). The R3-AFP model including last available pre-LT AFP value outperformed the original R3 model only based on explant features. The final R3-AFP scoring system provides a robust framework to design post-LT surveillance strategies, protocols, or adjuvant therapy trials, irrespective of criteria used to select patients with HCC for LT.

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Discrepancies between pretransplant tumour assessment and liver explant are frequent.

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The R3-AFP predictive model of recurrence was designed and validated in a large and international cohort of patients transplanted for HCC.

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The components of the final model are the following: number of nodules, size of the largest nodule, presence of MVI, nuclear grade, and last pre-LT AFP value.

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The R3-AFP model including the last available pre-LT AFP value outperformed the original R3 model only based on explant features.

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The final R3-AFP scoring system provides a standardised framework to refine post-LT management of patients, irrespective of criteria used to select patients with HCC for LT.

Artificial Intelligence in Liver Transplantation

BACKGROUND

Advancements based on artificial intelligence have emerged in all areas of medicine. Many decisions in organ transplantation can now potentially be addressed in a more precise manner with the aid of artificial intelligence.

METHOD/RESULTS

All elements of liver transplantation consist of a set of input variables and a set of output variables. Artificial intelligence identifies relationships between the input variables; that is, how they select the data groups to train patterns and how they can predict the potential outcomes of the output variables. The most widely used classifiers to address the different aspects of liver transplantation are artificial neural networks, decision tree classifiers, random forest, and naïve Bayes classification models. Artificial intelligence applications are being evaluated in liver transplantation, especially in organ allocation, donor-recipient matching, survival prediction analysis, and transplant oncology.

CONCLUSION

In the years to come, deep learning-based models will be used by liver transplant experts to support their decisions, especially in areas where securing equitability in the transplant process needs to be optimized.

The Importance of the Immunosuppressive Regime on Hepatocellular Carcinoma Recurrence After Liver Transplantation

PURPOSE

Hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT) occurs in approximately 20% of recipients and these patients have median about one year survival after diagnosis. Some immunosuppressive drugs can cause development of HCC recurrence, on the other hand some immunosuppressive drugs may have a positive effect for preventing HCC recurrence. Thus, immunosuppression (IS) modification may play a role in preventing HCC recurrence.

METHODS

In this review, we analyzed IS treatment strategy in two parts: before HCC recurrence following LT and after HCC recurrence following LT, and after HCC recurrence following LT.

RESULTS

There is no proven, optimal IS protocol to prevent HCC recurrence after transplantation. Therefore, individualized immunosuppressive treatments should be tailored to the biological behaviour of HCC. Forcing the immune tolerance in terms of recurrence can probably be expressed as the most appropriate post LT period. Once HCC recurrence has developed after transplantation, again, there is no commonly accepted, optimal IS treatment, but there is a tendency to switch to IS modifications that include mTORi by minimizing CNIs and MMF.

CONCLUSION

There is a need for well-designed, randomized, controlled clinical studies with larger numbers of patients on this subject.

THE MANAGEMENT OF POST-TRANSPLANTATION RECURRENCE OF HEPATOCELLULAR CARCINOMA

The annual incidence of hepatocellular carcinoma (HCC) continues to rise. Over the last two decades, liver transplantation (LT) has become the preferable treatment of HCC, when feasible and strict selection criteria are met. With the rise in HCC-related LT, compounded by downstaging techniques and expansion of transplant selection criteria, a parallel increase in number of post-transplantation HCC recurrence is expected. Additionally, in the context of an immunosuppressed transplant host, recurrences may behave aggressively and more challenging to manage, resulting in poor prognosis. Despite this, no consensus or best practice guidelines for post-transplantation cancer surveillance and recurrence management for HCC currently exist. Studies with adequate population sizes and high-level evidence are lacking, and the role of systemic and locoregional therapies for graft and extrahepatic recurrences remains under debate. This review seeks to summarize the existing literature on post-transplant HCC surveillance and recurrence management. It highlights the value of early tumour detection, re-evaluating the immunosuppression regimen, and staging to differentiate disseminated recurrence from intrahepatic or extrahepatic oligo-recurrence. This ultimately guides decision-making and maximizes treatment effect. Treatment recommendations specific to recurrence type are provided based on currently available locoregional and systemic therapies.

Management of Hepatocellular Carcinoma Recurrence after Liver Transplantation

Simple Summary

Hepatocellular carcinoma (HCC) is an increasingly important indication for liver transplantation (LT) worldwide. However, LT in the setting of liver cancer is burdened by the risk of tumor recurrence. The prognosis of patients with post-LT HCC recurrence is still very poor and several areas of uncertainty remain in the management of these patients. In this paper, we provide a comprehensive evaluation of available evidence regarding the management of HCC recurrence after LT, starting from the pre- and post-transplant stratification criteria and encompassing post-LT surveillance, preventive strategies and treatment. Much work has been done in the last several years but further effort is still needed in order to improve the outcome of these patients.

Abstract

Recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT), occurring in 10–15% of cases, is a major concern. A lot of work has been done in order to refine the selection of LT candidates with HCC and to improve the outcome of patients with recurrence. Despite this, the prognosis of these patients remains poor, partly due to the several areas of uncertainty in their management. Even if surveillance for HCC recurrence is crucial for early detection, there is currently no evidence to support a specific and cost-effective post-LT surveillance strategy. Concerning preventive measures, consensus on the best immunosuppressive drugs has not been reached and not enough data to support adjuvant therapy are present. Several therapeutic approaches (surgical, locoregional and systemic treatments) are available in case of recurrence, but there are still few data in the post-LT setting. Moreover, the use of immune checkpoint inhibitors is controversial in transplant recipients considered the risk of rejection. In this paper, the available evidence on the management of HCC recurrence after LT is comprehensively reviewed, considering pre- and post-transplant risk stratification, post-transplant surveillance, preventive strategies and treatment options.

HCC and Molecular Targeting Therapies: Back to the Future

Hepatocellular carcinoma (HCC) is one of the leading causes of death from cancer in the world. Recently, the effectiveness of new antiviral therapies and the HBV vaccine have reduced HCC’s incidence, while non-alcoholic steato-hepatitis is an emerging risk factor. This review focuses on antiangiogenic molecules and immune checkpoint inhibitors approved for HCC treatment and possible future approaches. Sorafenib was the first drug approved for the treatment of advanced HCC (aHCC) and it has been shown to increase survival by a few months. Lenvatinib, a multikinase inhibitor, has shown non-inferiority in survival compared with sorafenib and an improvement in progression-free survival (PFS). The combination of atezolizumab (an anti-PDL1 antibody) and bevacizumab (an anti-VEGF antibody) was the first drug combination approved for HCC, demonstrating improved survival compared with sorafenib (19.2 vs. 13.4 months). As a second line of therapy, three regimens (regorafenib, cabozantinib, and ramucirumab) have been approved for the treatment of aHCC after progression on sorafenib according to guidelines. Furthermore, nivolumab, pembrolizumab, and nivolumab plus ipilimumab have been approved by the FDA (2017, 2018, and 2020, respectively). Finally, immune target therapy, cancer vaccines, and epigenetic drugs represent three new possible weapons for the treatment of HCC.

Minimization of Immunosuppressive Therapy Is Associated with Improved Survival of Liver Transplant Patients with Recurrent Hepatocellular Carcinoma

Simple Summary

Liver transplantation is a curative treatment option for a subset of patients with hepatocellular carcinoma (HCC). However, about twenty percent of patients develop recurrence in the graft or at extrahepatic sites, which is associated with limited therapeutic options and poor survival. To date, management of the immunosuppressive regimen after recurrence and its impact on survival are unknown. In this retrospective study, we analyzed a cohort of liver recipients with HCC recurrence. Our findings indicate that reduction of immunosuppressive therapy after diagnosis of recurrence has a beneficial impact on patient survival. Therefore, we propose further investigation into the management of immunosuppressive therapy following recurrence.

Abstract

Introduction: Recurrence of hepatocellular carcinoma (rHCC) after liver transplantation (LT) is associated with limited survival. Therefore, identification of factors that prolong survival in these patients is of great interest. Surgical resection, radiotherapy, and transarterial chemoembolization (TACE) are established interventions to improve outcomes in these patients; however, the impact of immunosuppression is unknown. Methods: All patients diagnosed with rHCC in the follow-up after LT were identified from a database of liver recipients transplanted between 1988 and 2019 at our institution (Charité Universitätsmedizin Berlin, Germany). Based on the immunosuppressive regimen following diagnosis of rHCC and the oncological treatment approach, survival analysis was performed. Results: Among 484 patients transplanted for HCC, 112 (23.1%) developed rHCC in the follow-up. Recurrent HCC was diagnosed at a median interval of 16.0 months (range 1.0–203.0), with the majority presenting early after transplantation (63.0%, <2 years). Median survival after rHCC diagnosis was 10.6 months (0.3–228.7). Reduction of immunosuppression was associated with improved survival, particularly in patients with palliative treatment (8.4 versus 3.0 months). In addition, greater reduction of immunosuppression seemed to be associated with greater prolongation of survival. Graft rejection after reduction was uncommon (n = 7, 6.8%) and did not result in any graft loss. Patients that underwent surgical resection showed improved survival rates (median 19.5 vs. 8.7 months). Conclusion: Reduction of immunosuppressive therapy after rHCC diagnosis is associated with prolonged survival in LT patients. Therefore, reduction of immunosuppression should be an early intervention following diagnosis. In addition, surgical resection should be attempted, if technically feasible and oncologically meaningful.

Detection of circulating tumour cells enables early recurrence prediction in hepatocellular carcinoma patients undergoing liver transplantation

BACKGROUND & AIMS

Liver transplantation (LTx) is one of the most effective treatments for hepatocellular carcinoma (HCC); however, tumour recurrence after LTx often leads to poor outcomes. This study investigated the value of circulating tumour cells (CTCs) as a predictor of recurrence following LTx in patients with HCC.

METHODS

This analysis included 193 patients with HCC who underwent LTx at our institute and accepted pre- and post-operative CTC detection; 38 were selected for serial CTC monitoring. The predictive value of CTCs for tumour recurrence in patients with HCC following LTx was evaluated. Single-cell whole genome sequencing was used to characterize CTCs.

RESULTS

Overall, the CTC burden decreased after LTx (P < .05). Post-operative CTC count ≥ 1 per 5 mL peripheral blood was identified as a potential biomarker for predicting tumour recurrence after LTx, especially in patients with no detectable CTCs prior to LTx and negative tumour serological biomarkers. The predictive value of post-operative CTC count ≥ 1 per 5 mL blood was retained in patients who did not meet the Milan criteria, University of California San Francisco (UCSF) criteria, or Fudan criteria (all P < .05). Furthermore, post-operative serial CTC detection may be useful in post-surgical surveillance for HCC recurrence.

CONCLUSIONS

CTCs may be a useful biomarker to evaluate recurrence risk following LTx in patients with HCC. Evaluation based on CTC detection may enhance the post-transplant management of HCC, and improve the therapeutic efficacy of LTx.

Postoperative imaging surveillance for hepatocellular carcinoma: How much is enough?

BACKGROUND

The objective of the current study was to define trends in postoperative surveillance imaging following liver-directed treatment of hepatocellular carcinoma (HCC), and characterize the impact of high-intensity surveillance on long-term survival.

METHODS

Patients who underwent liver- directed therapy for HCC between 2004 and 2016 were identified using the SEER-Medicare database. Trends in surveillance intensity over time, factors associated with high surveillance intensity and the impact of surveillance on long-term outcomes were examined.

RESULTS

Utilization of high-intensity surveillance abdominal imaging (≥6 scans over 2 years) following liver-directed therapy of HCC decreased over time (2004-2007: n = 130, 36.1% vs. 2008-2011: n = 181, 29.5% vs. 2012-2016: n = 111, 24.5%; p_trend  < 0.001). History of chronic viral hepatitis (hepatitis B: odds ratio [OR], 1.98; 95% confidence interval [CI]: 1.15-3.43; hepatitis C: OR, 1.79; 95% CI: 1.32-2.43), presence of regional (vs. local-only) disease (OR, 1.47; 95% CI: 1.09-1.98) and receipt of transplantation (OR, 2.23; 95% CI: 1.57-3.17) were associated with higher odds of high intensity surveillance. Intensity of surveillance imaging was not associated with long-term survival (5-year overall survival: low-intensity, 48.1% vs. high-intensity, 48.9%; hazards ratio, 0.94; 95% CI: 0.78-1.13).

CONCLUSION

Utilization of posttreatment surveillance imaging decreased over time following liver-directed therapy for HCC. While utilization of high-intensity screening varied by HCC procedure performed, intensity of surveillance had no effect on survival.

Survival After Treatable Hepatocellular Carcinoma Recurrence in Liver Recipients: A Nationwide Cohort Analysis

Background

Survival after post-transplant recurrence of HCC is dismal, and almost all treatments for recurrent HCC are off-labeled, without an extensive large-scale analysis. We aimed to delineate their post-recurrence courses and define benchmarks for comparing future treatment effectiveness.

Methods

Three national databases, including health insurance, catastrophic illness, and the cause of death, were linked for cohort establishment and data collection during the period from 2005 to 2016. Patients with HCC recurrence ≥6 months after transplant surgery and under treatment were recruited for survival analysis. Selection of treatment strategies for HCC recurrence after liver transplant was based on the same criteria for those without liver transplant.

Results

Of 2,123 liver transplant recipients, 349 developed HCC recurrence ≥6 months after liver transplant, and the median recurrence time was 17.8 months post-transplant. Within 2 years of treatment, 61% patients showed recurrence (early recurrence group), and survival in these patients was poorer than in the late recurrence group. According to a multivariable analysis, the transplant era before 2008 and radiofrequency ablation were associated with good prognosis, whereas receiving sorafenib and radiotherapy was associated with poor prognosis. The effect of transplant era became insignificant after stratification by recently receiving pretransplant transarterial chemoembolization.

Conclusion

Timing of recurrence and interventions used were associated with the outcomes of patients with post-transplant HCC recurrence. These data provide the benchmark and indicate the critical period and high-risk factors for further therapeutic trial consideration.

Recurrence of hepatocellular carcinoma following liver transplantation

INTRODUCTION

Hepatocellular carcinoma (HCC) is an increasingly common disease with liver transplant (LT) the best long-term therapy for early stage disease. We will review the data for assessing risk and managing recurrence for patients undergoing LT for HCC.

AREAS COVERED

In this review, we will provide an overview of methods of patient risk stratification in the post-transplant period, the data around surveillance for HCC recurrence, and the evidence for and against post-LT adjuvant treatment strategies. Finally, we will provide data regarding treatment options for patients with HCC recurrence after LT. Using an extensive search of original papers and society guidelines, this paper provides a comprehensive review of the data for assessing risk and managing recurrence for patients undergoing LT for HCC.

EXPERT OPINION

The development of multiple post-transplant prognostic scoring systems have allowed for improved assessment of recurrence risk and stratification of patients. However, the ability to translate this information into surveillance and therapeutic strategies that improve patient outcomes still have to be fully demonstrated. Post-LT immunosuppression strategies have been implemented in order to attempt to reduce this risk. Evidence-based strategies for managing recurrent HCC are evolving. We expect that with further understanding of individual patient characteristics will allow for optimal therapeutic selection.

Ribavirin Improves NK Cell IFNγ Response During Sofosbuvir-based DAA Therapy in CV-infected Liver Transplant Recipients

BACKGROUND

Chronic hepatitis C virus (HCV) infection is characterized by activation of natural killer (NK) cells. Here, we asked whether HCV-elimination by sofosbuvir-based direct-acting antivirals (DAAs) and addition of RBV improves NK cell function in liver transplant (LTx) recipients.

METHODS

We analyzed NK cell degranulation and IFNγ-response along with STAT-1 and STAT-4 phosphorylation in 29 HCV-infected LTx-recipients and 17 HCV-infected patients during DAA-treatment.

RESULTS

Compared to uninfected LTx-recipients, NK cells from HCV-infected LTx-recipients were polarized towards cytotoxicity with increased CD107a-degranulation (10.1% vs 14.6%; P=0.0263) and reduced capacity to produce IFNγ (43.0% vs 26.7%; P=0.0002). The altered phenotype of NK cells in HCV-infected LTx-recipients was accompanied by increased STAT-1 (44.6% vs 87.4%; P<0.0001) and STAT-1 phosphorylation (0.7% vs 8.9%; P=0.0005) compared to pSTAT-4 IFNα-induction (29.9% vs 17.6%; P=0.0014). Successful DAA-therapy did not affect CD107a-degranulation, but decreased STAT-1. RBV cotreatment with DAA-therapy for HCV increased CD56Bright NK cell IFNγ-responses in LTx-recipients (70.9% vs 89.2%; P=0.002) and this correlated to an increase in the inducibility of pSTAT-4 (MFI 157 vs 173; P=0.0002).

CONCLUSION

RBV cotreatment of HCV-infection improved pSTAT4-dependent IFNγ-production in NK cells. This is relevant especially for immunocompromised patients such as LTx-recipients or patients with end-stage liver disease.

A National Survey of Hepatocellular Carcinoma Surveillance Practices Following Liver Transplantation

Recurrence of hepatocellular carcinoma (HCC) is an important predictor of survival after liver transplantation (LT). Recent studies show that early diagnosis, aggressive treatment, and surveillance may improve outcomes after HCC recurrence. We sought to determine the current practices and policies regarding surveillance for HCC recurrence after LT.

Methods

We conducted a web-based national survey of adult liver transplant centers in the United States to capture center-specific details of HCC surveillance post-LT. Responses were analyzed to generate numerical and graphical summaries.

Results

Of 101 eligible adult liver transplant centers, 48 (48%) centers across the United States responded to the survey. Among the participating centers, 79% stratified transplant recipients for HCC recurrence risk, while 19% did not have any risk stratification protocol. Explant microvascular invasion (mVI) was the most common factor used in risk stratification. Use of pretransplant serum biomarkers such as alpha-fetoprotein (AFP) was variable, with only 48% of the participating centers reporting specific "cutoff" values. While a majority of centers (88%) reported having a routine imaging protocol for HCC recurrence surveillance, there was considerable heterogeneity in terms of frequency and duration of such surveillance. Of the centers that did risk stratify patients to identify those at higher risk of HCC recurrence, about 50% did not change their surveillance protocol.

Conclusions

Our study affirms significant variability in center practices, and our results reflect the need for high-quality studies to guide risk stratification and surveillance for HCC recurrence.

Surveillance Strategy for Patients With BCLC Stage B Hepatocellular Carcinoma After Achieving Complete Remission: Data From the Real World

Purpose: There is a lack of consensus on the surveillance strategy for Barcelona Clinic liver cancer (BCLC) stage B hepatocellular carcinoma (HCC) patients with complete remission (CR). We performed a real-world, retrospective analysis of the surveillance strategy for BCLC stage B HCC patients after radical therapy with CR to support clinical decision-making.

Materials and Methods: We analyzed 546 BCLC stage B HCC patients with CR after radical treatments (surgery/ablation) at Sun Yat-sen University Cancer Center, from January 2007 to December 2019. The intensity of surveillance interval was defined as the mean of surveillance interval within 2 years. The primary endpoint of the study was overall survival (OS) and extra-Milan criteria relapse.

Results: During a median follow-up time of 23.9 months (range = 3.1–148.3 months), there were 11.9% of patients died, 56.6% of patients developed recurrence, the vast majority of patients experienced recurrence within 2 years, and 27.8% patients developed extra-Milan criteria recurrence. The median disease-free survival and OS were 33.6 and 60.0 months, respectively. Patients were divided into regular surveillance group (RS) (≤4.3 months) and irregular surveillance (IRS) group (>4.3 months) based on the optimal cutoff value of the intensity of surveillance interval. The RS group owned a lower incident of extra-Milan criteria relapse and smaller and fewer tumors at recurrence than IRS group, which contributed to the prolonged OS. Besides, the cutoff values of surveillance interval that could lead to significant differences in the incidence of extra-Milan criteria relapse during 0–6, 6–12, and 12–18 months after CR were 2.6, 2.9, and 3 months, respectively.

Conclusions: The average surveillance interval for patients with BCLC stage B HCC achieved CR should not exceed 4.3 months during the first 2 years' follow-up. During three different phases of the initial 18 months after CR, individualized surveillance showed intervals no more than 3 months were required to reduce the incidence of extra-Milan criteria relapse.