Liver Transplantation for Malignant Primary Pediatric Hepatic Tumors

Critical elements of pediatric liver cancer surgery

The appropriate management of pediatric liver malignancies, primarily hepatoblastoma and hepatocellular carcinoma, requires an in depth understanding of contemporary preoperative risk stratification, experience with advanced hepatobiliary surgery, and a good relationship with one's local or regional liver transplant center. While chemotherapy regimens have become more effective, operative indications more well-defined, and overall survival improved, the complexity of liver surgery in small children provides ample opportunity for protocol violation, inadequate resection, and iatrogenic morbidity. These guidelines represent the distillation of contemporary literature and expert opinion as a means to provide a framework for preoperative planning and intraoperative decision-making for the pediatric surgeon.

Strategy for hepatoblastoma with major vascular involvement: A guide for surgical decision-making

BACKGROUND

Surgical management of tumor thrombus extending to the major vascular system for children with hepatoblastoma is challenging and insufficiently discussed.

METHODS

We conducted a retrospective review of hepatoblastoma with tumor thrombus extending to the major vascular system (inferior vena cava, 3 hepatic veins, and portal vein trunk) treated at our center between May 2010 and June 2021. We describe our preoperative assessment, surgical strategies, and outcomes.

RESULTS

We identified 9 patients (median age at the diagnosis: 3.4 years). All patients received chemotherapy before liver surgery. At the time of the diagnosis, tumor thrombus extended to the portal vein trunk (n = 6), inferior vena cava (n = 3), and 3 hepatic veins (n = 2). Among the 9 patients, 4 underwent liver resection. Liver transplantation was performed in 5 patients. The inferior vena cava wall was circumferentially resected for tumor removal in 1 patient and partially resected in 2 patients. One patient underwent liver transplantation using veno-venous bypass. Patients with tumor thrombus extending to the portal vein trunk were more likely to be managed by liver transplantation in comparison to those with tumor thrombus spreading to the inferior vena cava. The median follow-up period was 5.5 years. One patient underwent transhepatic balloon dilatation for biliary stricture after liver resection. Tumor recurrence was seen in 3 patients (33.3%; lung, n = 2; lymph node and liver, n = 1). No patients died during the follow-up period.

CONCLUSION

Surgical intervention for pediatric hepatoblastoma with tumor thrombus extending into the major vascular system is safe, feasible, and achieves excellent outcomes.

Integration of a dedicated management protocol in the care of pediatric liver cancer: From specialized providers to complication reduction

INTRODUCTION

Up to a third of children undergoing partial hepatectomy for primary hepatic malignancies experience at least one perioperative complication, with a presumed deleterious effect on both short- and long-term outcomes. We implemented a multidisciplinary treatment protocol in the management of these patients in order to improve complication rates following partial hepatectomy.

METHODS

A retrospective chart review was completed for all patients < 18 years of age who underwent liver resection at our institution between 2002 and 2019 for primary hepatic cancer. Demographic, intraoperative, postoperative, pathologic, and outcome data were analyzed for perioperative complications using the CLASSIC and Clavien-Dindo (CD) scales, event-free survival (EFS) and overall survival (OS).

RESULTS

A total of 73 patients were included in the analysis with 33 prior-to and 40 after dedicated provider protocol implementation. Perioperative complication rates decreased from 52% to 20% (p = 0.005) with major complications going from 18% to 10% (p = 0.31). On multivariable logistic regression, protocol implementation was associated with a reduction in any (OR 0.29 [95% CI 0.09 - 0.89]) but not major complications. On multivariate cox models, post protocol implementation was associated with improved event free survival (EFS) (HR 0.19 (0.036 - 0.195). Among patients with a diagnosis of hepatoblastoma (n = 62), the occurrence of a major perioperative complication was associated with a worse EFS (HR=5.45, p = 0.03) on multivariate analysis, however this did not translate into an impact on overall survival.

CONCLUSIONS

Our results demonstrate that, for children with primary liver malignancies, a dedication of patients to high-volume surgeons can improve rates of complications of liver resections and may improve the oncological outcome of hepatoblastoma.

Predictors of survival following liver transplantation for pediatric hepatoblastoma and hepatocellular carcinoma: Experience from the Society of Pediatric Liver Transplantation (SPLIT)

Management of unresectable pediatric hepatoblastoma (HB) and hepatocellular carcinoma (HCC) remains challenging. The Society of Pediatric Liver Transplantation (SPLIT) database was used to study survival predictors in pediatric liver transplantation (LT) for HB and HCC. Event-free survival (EFS), associated risk factors, and postoperative complications were studied in children requiring LT for HB/HCC at 16 SPLIT centers. Three-year EFS was 81% for HB (n = 157) and 62% for HCC (n = 18) transplants. Of HB transplants, 6.9% were PRETEXT II and 15.3% were POST-TEXT I/II. Tumor extent did not impact survival (p = NS). Salvage (n = 13) and primary HB transplants had similar 3-year EFS (62% versus 78%, p = NS). Among HCC transplants, 3-year EFS was poorer in older patients (38% in ≥8-year-olds vs 86% <8-year-olds) and those with larger tumors (48% for those beyond versus 83% within Milan criteria, p = NS). Risk of infection (HR 1.5, 95% CI 1.1-2.2, p = .02) and renal injury (HR 2.4, 95% CI 1.7-3.3, p < .001) were higher in malignant versus nonmalignant LT. Survival is favorable for pediatric HB and HCC LT, including outcomes after salvage transplant. Unexpected numbers of LTs occurred in PRE/POST-TEXT I/II tumors. Judicious patient selection is critical to distinguish tumors that are potentially resectable; simultaneously, we must advocate for patients with unresectable malignancies to receive organs.

Liver Transplantation for Pediatric Hepatocellular Carcinoma: A Systematic Review

Simple Summary

Hepatocellular carcinoma is a type of primary liver cancer and the second most common type of liver cancer in children. Although partial hepatectomy can be curative, many children present with tumors that are not amenable to resection and thus the only potentially curative option is liver transplantation. In this systematic review, we have pooled the data from the worldwide literature and showed that survival after liver transplantation for pediatric hepatocellular carcinoma is favorable and many children do well even if their tumors exceed certain potentially restrictive criteria originally developed to select adults with hepatocellular carcinoma for liver transplantation.

Abstract

Liver transplantation (LT) is the only potentially curative option for children with unresectable hepatocellular carcinoma (HCC). We performed a systematic review of the MEDLINE, Scopus, Cochrane Library, and Web of Science databases (end-of-search date: 31 July 2020). Our outcomes were overall survival (OS) and disease-free survival (DFS). We evaluated the effect of clinically relevant variables on outcomes using the Kaplan–Meier method and log-rank test. Sixty-seven studies reporting on 245 children undergoing LT for HCC were included. DFS data were available for 150 patients and the 1-, 3-, and 5-year DFS rates were 92.3%, 89.1%, and 84.5%, respectively. Sixty of the two hundred and thirty-eight patients (25.2%) died over a mean follow up of 46.8 ± 47.4 months. OS data were available for 222 patients and the 1-, 3-, and 5-year OS rates were 87.9%, 78.8%, and 74.3%, respectively. Although no difference was observed between children transplanted within vs. beyond Milan criteria (p = 0.15), superior OS was observed in children transplanted within vs. beyond UCSF criteria (p = 0.02). LT can yield favorable outcomes for pediatric HCC beyond Milan but not beyond UCSF criteria. Further research is required to determine appropriate LT selection criteria for pediatric HCC.

An analysis of the outcomes in living donor liver transplantation for pediatric malignant hepatic tumors using nationwide survey data in Japan

Malignant hepatic tumors (MHTs) in children are rare and account for approximately 5% of candidates for pediatric liver transplantation (LT) in Japan. We conducted a national survey of pediatric patients undergoing living donor LT for MHTs between October 1990 and April 2018. In total, 116 children underwent LT for MHTs during this study period: 100 hepatoblastomas (HBLs), 10 hepatocellular carcinomas (HCCs), and six other MHTs. The overall patient survival rate at 5 years was 81.3% for HBL, 60.0% for HCC, and 80.0% for other MHTs (P = 0.047). In patients with HBL, there was no significant difference in the 1- and 5-year patient survival rates between patients undergoing primary LT and those who received salvage LT for tumor recurrence (89.7%, 81.6% vs. 88.0%, 76%; P = 0.526). The 5-year overall survival rate after LT for HBL significantly improved from 63.2% in 1996-2008 to 89.8% in 2009-2018 (P = 0.018). The presence of lung metastasis before LT had no significant influence on the long-term survival (P = 0.742). Five patients with HCC died, including two who fell outside the Milan criteria. In conclusion, LT for pediatric MHTs, especially HBL, is a valuable treatment option for select patients.

Liver Tumours in Children: The Hepatologist's View

ABSTRACT

Diagnostic and therapeutic innovations have changed the way we now approach liver tumours in children and adolescents. Novel imaging tools, increasing awareness, and surveillance has led to early diagnosis of benign and malignant liver tumours. Multidisciplinary interventions have favourably altered the natural course in some liver tumours. The role of liver transplantation is expanding and has become fully integrated into today's therapeutic algorithms. Transarterial locoregional and ablation therapies have been successful in adults and are being explored in children to facilitate resectability and improve outcome. For the first time, North American, Japanese, and European experts have designed a global trial to optimize management of malignant liver tumours and aim to find signature molecular profiles that will translate to individualised treatment strategies.This article aims to offer an overview of recent advances in our understanding of liver tumours in children. It focuses on the paediatric hepatologist's view and their role in the multidisciplinary management of benign and malignant liver tumours.

Outcomes following liver transplantation in young infants: Data from the SPLIT registry

Liver transplantation (LT) in young patients is being performed with greater frequency. We hypothesized that objective analysis of pre-, intra-, and postoperative events would help understand contributors to successful outcomes and guide transplant decision processes. We queried SPLIT registry for pediatric transplants between 2011 and 2018. Outcomes were compared for age groups: 0-<3, 3-<6, 6-<12 months, and 1-<3 years (Groups A, B, C, D respectively) and by weight categories: <5, 5-10, >10 kg; 1033 patients were available for analysis. Cholestatic disease and fulminant failure were highest in group A and those <5 kg; and biliary atresia in group C (72.8%). Group A had significantly higher life support dependence (34.6%; P < .001), listing as United Network for Organ Sharing status 1a/1b (70.4%; P < .001), and shortest wait times (P < .001). The median (interquartile range) for international normalized ratio and bilirubin were highest in group A (3.0 [2.1-3.9] and 16.7 [6.8-29.7] mg/dL) and those <5 kg (2.6 [1.8-3.4] and 13.5 [3.0-28.4] mg/dL). A pediatric end -stage liver disease score ≥40, postoperative hospital stays, rejection, and nonanastomotic biliary strictures were highest in group A with lowest survival at 93.1%. Infants 0 to <3 months and those <5 kg need more intensive care with lower survival and higher complications. Importantly, potential LT before reaching status 1a/1b and aggressive postoperative management may positively influence their outcomes.

Undifferentiated sarcoma of the liver: Multicenter international experience of the Cooperative Soft-Tissue Sarcoma Group and Polish Paediatric Solid Tumor Group

BACKGROUND

Undifferentiated embryonal sarcomas of the liver (UESL) are extremely rare and continue to pose a diagnostic and therapeutic challenge. The aim of the study was to present a multicenter experience of the German CWS and Polish PPSTG groups in the treatment of UESL in children.

PROCEDURE

Twenty-five patients were treated according to the CWS-96, CWS-2002, and CYVADIC protocols. Distant metastases were observed in four cases (16%). In four cases, an initial disease presentation mimicked other entities. A pure cystic appearance of liver mass led to misdiagnosis of hydatid cyst in three cases. In one case, laparotomy was performed due to the signs of appendicitis, and bleeding from ruptured liver tumor was found. All these patients were finally diagnosed as UESL.

RESULTS

Thirteen patients received preoperative chemotherapy. Partial response was observed in 10 cases. Tumor resection was performed in 20 patients (primary resections, 12; delayed resections-, 8). In five patients, the primary tumor never became operable. The macroscopically complete resection rate was 95% (19/20). Postoperative chemotherapy was given to 20 children. Local radiotherapy was used in three children. After a median follow-up time of 136 months, 17 patients (68%) were alive with no evidence of disease. All children with unresectable tumor and three out of four patients with distant metastases died. The five-year overall survival (OS) rate was 72%.

CONCLUSIONS

In summary, a complete tumor excision plays the central role in the treatment of UESL. A cystic presentation of the liver lesion on imaging does not exclude the diagnosis of malignant tumor.

Liver Transplantation for Colorectal and Neuroendocrine Liver Metastases and Hepatoblastoma. Working Group Report From the ILTS Transplant Oncology Consensus Conference

Liver transplantation (LT) for unresectable colorectal liver metastases has long been abandoned because of dismal prognoses. After the dark ages, advances in chemotherapy and diagnostic imaging have enabled strict patient selection, and the pioneering study from the Oslo group has contributed to the substantial progress in this field. For unresectable neuroendocrine liver metastases, LT for patients who met the Milan criteria was able to achieve excellent long-term outcomes. The guidelines further adopted in the United States and Europe were based on these criteria. For hepatoblastoma, patients with unresectable and borderline-resectable disease are considered good candidates for LT; however, the indications are yet to be defined. In the budding era of transplant oncology, it is critically important to recognize the current status and unsolved questions for each disease entity. These guidelines were developed to serve as a beacon of light for optimal patient selection for LT and set the stage for future basic and clinical studies.

Surgical Therapy for Pediatric Hepatoblastoma in the USA over the Last Decade: Analysis of the National Cancer Database

INTRODUCTION

Hepatoblastoma (HB) is a rare childhood malignancy with hepatic resection (HR) or liver transplantation (LT) providing the best chance of cure. In this study, we analyze the National Cancer Database lacks (NCDB) to compare outcomes following HR and LT for HB.

METHODS

Review of the US experience with surgical (HR and LT) management of pediatric (< 18 years) HB over the last decade (2004-2014) using data extracted from the NCDB.

RESULTS

A total of 628 children underwent surgical treatment for HB during the study period: HR in 525 (83.6%) and LT in 103 (16.4%). The two groups were comparable for age, sex, race, tumor size, and metastatic disease at initial diagnosis. LT group had significantly higher number of patients with bilobar disease (40 vs 21%; p < 0.001), longer median time from diagnosis to surgery (120 vs 78 days; p < 0.001), and longer post-operative length of stay (LOS) (14 vs 6 days; p < 0.001). There were no differences in rates of 30-day readmission and 30- or 90-day mortality between groups. Both groups had comparable 5-year overall survival (OS) (84.1% HR vs 80.0% LT; p = 0.4). Univariate analysis identified metastatic disease at initial presentation (HR 2.56, CI 1.51-4.35) and age ≥ 4 years (HR 2.68, CI 1.5-4.7) as risk factors for worse overall 5-yr OS, while administration of adjuvant chemotherapy was associated with improved 5-yr OS (92.3% with chemo vs 85.4% without chemo; HR 0.51, CI 0.31-0.84).

CONCLUSION

The outcome of HB has improved compared with historical controls. Age at presentation, metastatic disease, and post-operative chemotherapy impact outcomes.

Surgical management of locally-advanced and metastatic hepatoblastoma

Advanced stage hepatoblastoma, including both locally advanced primary tumors as well as metastatic disease, poses unique clinical challenges. Despite substantial advances in chemotherapeutics, surgical extirpation remains the mainstay of cure for this tumor. Locally advanced tumors that involve multiple hepatic lobes and/or invade significant vascular structures can be managed either by complex hepatic resections or liver transplantation. We review the indications, roles, and outcomes of these surgical approaches as well as those for the resection of pulmonary metastases.

How Do Synchronous Lung Metastases Influence the Surgical Management of Children with Hepatoblastoma? An Update and Systematic Review of the Literature

Approximately 20% of children with hepatoblastoma (HB) have metastatic disease at diagnosis, most frequently in the lungs. In children with HB, lung metastatic disease is associated with poorer prognosis. Its treatment has been approached with a variety of methods that integrate chemotherapy and surgical resection. The timing and feasibility of complete extirpation of lung metastases, by chemotherapy and/or metastasectomy, is crucial for the surgical treatment of the primary liver tumor, which can vary from major hepatic resections to liver transplantation (LT). In children with unresectable HB, which can be surgically treated only by LT, the persistence of unresectable metastases after neoadjuvant chemotherapy excludes the possibility of recurring to LT with consequent negative impact on patients’ outcomes. Due to limited evidence and experience, there is no consensus amongst oncologists and surgeons across institutions regarding the surgical treatment for HB with synchronous metastatic lung disease. This narrative review aimed to update the current management of pulmonary metastasis in children with HB and to define its role in the decision-making strategy for the surgical approach to primary liver tumours.

Hepatoblastoma-The Evolution of Biology, Surgery, and Transplantation

The most common primary malignant liver tumor of childhood, hepatoblastoma has increased in incidence over the last 30 years, but little is still known about its pathogenesis. Discoveries in molecular biology provide clues but have yet to define targeted therapies. Disease-free survival varies according to stage, but is greater than 90% in favorable risk populations, in part due to improvements in chemotherapeutic regimens, surgical resection, and earlier referral to liver transplant centers. This article aims to highlight the principles of disease that guide current treatment algorithms. Surgical treatment, especially orthotopic liver transplantation, will also be emphasized in the context of the current Children's Oncology Group international study of pediatric liver cancer (AHEP-1531).

Improved contemporary outcomes of liver transplantation for pediatric hepatoblastoma and hepatocellular carcinoma

PURPOSE

Improvement in outcomes of LT for pediatric HB and HCC has been reported in small series. We analyzed national outcomes and changes in donor, recipient, and perioperative factors over time that may contribute to survival differences.

METHODS

The UNOS database was queried for patients age <21 years that underwent LT for a primary diagnosis of HB or HCC (1987-2017). Subjects were divided into historic (transplant before 2010) and contemporary (transplant after 2010) cohorts. Baseline characteristics were compiled and examined. Survival was estimated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

In total, 599 children with HB received LT (320 historic vs 279 contemporary). Concurrently, 141 children with HCC received LT (92 historic vs 49 contemporary). For both tumors, waitlist time decreased (HB 56.2 days historic vs 33.2 days contemporary, P = 0.017; HCC 189.3 days historic vs 71.7 days contemporary, P = 0.012). In the historic cohorts, patients with HB had a 1-year and 5-year OS of 84.6% and 75.1%, respectively. Survival for HCC was 84.4% and 59.9%, respectively. Outcomes improved in the contemporary era to 89.1% and 82.6% for HB, and 94.7% and 80.8% for HCC, respectively (both log-rank test P < 0.0001).

CONCLUSION

Outcomes of LT have improved significantly, with contemporary survival now equivalent between these tumors and exceeding 80% 5-year OS. Future studies are needed to explore whether offering LT in patients that are resectable is justifiable.

Hepatocellular carcinoma in children: hepatic resection and liver transplantation

Hepatocellular carcinoma (HCC) is a rare malignancy in children and at the time of diagnosis up to 80% of pediatric HCC are unresectable due to large and multiple lesions. The majority of pediatric HCC occurs on a background of normal liver, and consequently the absence of concomitant chronic liver disease generally allows tolerating pre- and post-operative chemotherapy. Based on the large experiences of adult HCC and pediatric hepatoblastoma, in the last years a multidisciplinary aggressive treatment composed of surgical resection and chemotherapy (based on cisplatin and doxorubicin) has been proposed, improving patient outcomes and recurrence rate in children with HCC. However, the overall survival rate in children with HCC is not satisfactory yet; while the 5-year survival rate may achieve up to 70-80% in non-metastatic resectable HCC, it remains <20% in children with unresectable HCC. The mainstay of the pediatric HCC therapeutic strategy is the radical tumor resection, weather by hepatic resection or liver transplantation, nevertheless the best surgical approaches as well as the optimal neoadjuvant and adjuvant treatment are still under debate. Different strategies have been explored to convert unresectable HCC into resectable tumors by extending criteria for surgical treatment and/or associating multi-modal treatments, such as systemic and local-regional therapy, but universal recommendation needs to be defined yet. The purpose of this review is to outline the role of different surgical approaches, including hepatic resection and liver transplantation, in pediatric HCC with or without underlying chronic liver disease.

Long-term outcomes of liver transplantation for hepatoblastoma: A single-center 14-year experience

HB is the most common primary liver tumor in children. Complete tumor excision, either by partial resection or by total hepatectomy and liver transplantation, in combination with chemotherapy provides the best chance for cure. We performed a retrospective analysis of patients who underwent liver transplantation for HB and herein present our 14-year single-institution experience. Twenty-five patients underwent liver transplantation for HB at a median age of 26 months (IQR: 15-44). Graft survival was 96%, 87%, and 80% at 1, 3, and 5 years, respectively. There were four patient deaths, three of them due to disease recurrence within the first year post-transplant. Ten-year overall survival was 84%. Three recipients initially presented with pulmonary metastases and underwent resection of metastatic disease, of which two are alive at 3.9 years. Of three patients who underwent salvage transplants, two are alive at 1.5 years after transplant. Non-survivors were associated with lower median alpha fetoprotein value at presentation compared to survivors (21 707 vs 343 214; P = .04). In conclusion, the overall long-term outcome of primary liver transplantation for HB is excellent. Tumor recurrence was the highest contributor to mortality. Even patients with completely treated pulmonary metastases prior to transplant demonstrated a favorable survival.