Renal function following liver transplantation for unresectable hepatoblastoma

Reappraisal of liver resection as an alternative to transplantation in locally advanced hepatoblastoma: A systematic review and analysis of pooled individual patient data

BACKGROUND

There is ongoing debate regarding liver transplantation (LT) versus liver resection (LR) for locally advanced hepatoblastoma. However, comparative studies are lacking. Consequently, a significant evidence gap persists, hindering the establishment of consensus guidelines. This study aimed to compare LT and LR for locally advanced hepatoblastoma, using predefined inclusion criteria to ensure comparable intervention groups.

METHODS

According to current Children's Oncology Group (COG) and SIOPEL (European Childhood Liver Tumour Study Group) recommendations, hepatoblastoma that requires LT evaluation was defined as either PRETEXT (PRE-Treatment EXTent of tumor) IV F+, POST-TEXT (POST-Treatment EXTent of tumor) IV, POST-TEXT P+, and/or POST-TEXT V+. A systematic literature search (Medline/Web-of-Science/Embase) was performed. Only patients who met the aforementioned criteria were included. Patient data were extracted individually and pooled.

RESULTS

A total of 189 patients with locally advanced hepatoblastoma from 55 studies met the specified criteria, with 111 undergoing LT and 78 LR. There were no significant differences between the two groups in age, alpha-fetoprotein (AFP), and PRETEXT stages. Local recurrence was more common after LR (14% vs. 3% in LT, p = .008), while distant recurrence was more often observed after LT (16% vs. 5% in LR, p = .035). Overall survival (OS) and event-free survival (EFS) did not differ significantly between LT and LR (5-year OS: LT = 75.3% [95% confidence interval: 66.5-85.2], LR = 87.6% [80.4-95.6], p = .140; 5-year EFS: LT = 68.5% [59.3-79.1], LR = 71.1% [60.7-83.3], p = .700).

CONCLUSION

Real-life data revealed that a considerable number of patients with locally advanced hepatoblastoma underwent LR. This analysis suggests that outcomes are similar and favorable for both approaches. LR can therefore be considered an effective alternative to LT in selected cases even in locally advanced hepatoblastoma.

Glomerular filtration rate in liver transplant for unresectable hepatoblastoma

Most children with hepatoblastoma manifest, at the time of LT, a decrease in renal function due to chemotherapy that could be further deteriorated by the use of calcineurin inhibitors. The purpose of this work was to examine the long-term follow-up of renal function in a cohort of children transplanted for unresectable hepatoblastoma. We present a retrospective observational study of 10 pediatric patients who received a LT for unresectable hepatoblastoma between 1996 and 2016. All patients included in this study were followed up on a regular basis and were assessed for GFR before transplantation and at least once a year during follow-up. All patients received standardized chemotherapy treatment for hepatoblastoma and immunosuppression according to hospital protocols. There was a marked decrease in GFR at the time of the LT in five patients presenting renal complications during the pretransplant cycles of chemotherapy. Three patients, one of them with prior kidney involvement, presented complications after LT, namely acute kidney failure and decrease in GFR. Those patients who presented with the lowest GFR at the time of LT eventually recovered renal function at levels similar to the rest of the group on follow-up. Chemotherapy-induced nephrotoxicity is a concern in patients treated for hepatoblastoma. Some individuals will develop low GFR after chemotherapy; therefore, strict follow-up is recommended, as low GFR may affect the doses of subsequent chemotherapy and immunosuppression. Stabilization of GFR levels and occasional improvement can be observed in the post-transplant period.

Benefit of early inflow exclusion during living donor liver transplantation for unresectable hepatoblastoma

BACKGROUND

Hepatoblastoma (HB) is a highly malignant primary liver tumor in children. Although liver transplantation (LT) is an effective treatment for unresectable HB with good long-term outcomes, post-transplant survival is mainly affected by recurrence, despite adjuvant chemotherapy. Novel strategies are needed to improve the outcomes in patients undergoing LT for unresectable HB.

PATIENTS AND METHODS

Twelve children received LT for unresectable HB. In 9 patients, we applied early exclusion of hepatic inflow (hepatic artery and portal vein) and creation of a temporary portocaval shunt during LT.

RESULT

There were differences in the duration of and the blood loss during operation as compared with previously reports. The estimated glomerular filtration rate was well preserved at 3, 6, and 12months and the latest follow-up after LT, and the recurrence-free survival was 88.9%.

CONCLUSION

Early inflow control during LT for unresectable HB may benefit recurrence-free survival by minimizing blood loss and tumor dissemination, preserving renal function and allowing early adjuvant chemotherapy.

Hepatoblastoma state of the art: pre-treatment extent of disease, surgical resection guidelines and the role of liver transplantation

PURPOSE OF REVIEW

This is part two of a two-part state of the art--hepatoblastoma. International hepatoblastoma specialists were brought together to highlight advances, controversies, and future challenges in the treatment of this rare pediatric tumor.

RECENT FINDINGS

Pretreatment extent of disease (PRETEXT) is a grouping system introduced as part of the multicenter international childhood liver tumors strategy group, SIOPEL-1, study in 1990. The system has been refined over the ensuing years and has now come to be adopted for risk stratification by all of the major pediatric liver tumor multicenter trial groups. PRETEXT is being intensively studied in the current Children's Oncology Group (COG) AHEP-0731 trial in an attempt to validate interobserver reproducibility and ability to monitor response to neoadjuvant chemotherapy, and determine surgical resectability. PRETEXT is now used to identify those patients who are at risk for having an unresectable tumor and who should be referred to a liver specialty center with transplant capability early in their treatment schema.

SUMMARY

International collaborative efforts in hepatoblastoma have led to increased refinements in the use of the PRETEXT and post-treatment extent to define prognosis and surgical resectability. PRETEXT criteria which suggest a possible need for liver transplantation are discussed in detail.

Safety of minimal immunosuppression in liver transplantation for hepatoblastoma

BACKGROUND

Despite aggressive chemotherapy, recurrence of disease remains the leading cause of death after liver transplantation (LTx) for hepatoblastoma (HB). Unfortunately, little is known about the effects of immunosuppression on recurrence and posttransplant outcomes. We hypothesized that minimal immunosuppression can be safely used in these recipients.

METHODS

In 2004, we adopted a minimal immunosuppression regimen using daclizumab induction and tacrolimus monotherapy. Kaplan-Meier survival curves were generated.

RESULTS

From 2004 to 2006, 6 children underwent primary LTx for HB with neoadjuvant and adjuvant chemotherapy. Patient survival was 100% at 12 months and at 24 months, without graft loss. One patient died 28 months after transplantation. Recurrence-free survival was 83% at 12 months and at 24 months. Despite minimal immunosuppression (IS), 4 of 6 HB recipients remained rejection-free. When compared to other LTx recipients receiving minimal IS, HB recipients trended to have better rejection-free survival (HB, 83% at 12 months and 62.5% at 24 months vs all others, 36% and 36%, respectively; P = .19).

CONCLUSION

Our short-term patient and graft survival rates are comparable to those reported for all HB recipients in the United Network for Organ Sharing database. Although not statistically significant, our rejection-free survival data suggest that HB recipients may be less likely to reject than other recipients.

Current issues in pediatric transplantation

Pediatric solid organ transplantation is so successful that >80% of children will survive to become teenagers and adults. Therefore, it is essential that these children maintain a good quality life, free of significant long-term side effects. While intensive immunosuppressive regimens (containing CsA, tacrolimus, MMF, and steroids) effectively reduce acute or chronic rejection, they can produce long-term side effects including viral infection, renal dysfunction, hypertension, and stunting. The development of effective methods of diagnosis, prevention, and treatment of CMV means that this is no longer a significant cause of mortality, but morbidity remains high. In contrast, infection rates of EBV remain high in EBV-negative pre-transplant patients. However, pre-emptive reduction of immunosuppression or treatment with rituximab or adoptive T-cell therapy is effective in preventing/treating post-transplant lymphoproliferative disease. Recent protocols have concentrated on reducing CsA immunosuppression, to prevent unacceptable cosmetic effects, and to reduce the hypertension, hyperlipidemia, and nephrotoxicity. Both CsA and tacrolimus cause a 30% reduction in renal function, with 4-5% of patients developing severe chronic renal failure. The use of IL-2 inhibitors for induction therapy with low-dose calcineurin inhibitors, in combination with renal-sparing drugs such as MMF or sirolimus for maintenance immunosuppression, should prevent significant renal dysfunction in the future. The concept of steroid-free immunosuppression with IL-2 inhibitors, tacrolimus, and MMF is an attractive option, which may reduce stunting and renal dysfunction. However, these regimens may be associated with the increased development of de-novo autoimmune hepatitis in 2-3% of children. The most important challenge to long-term survival in transplanted children is the management of non-adherence and other adolescent issues, particularly when transferring to adult units, as this is the time when many successful transplant survivors lose their grafts.

Unresectable multifocal hepatoblastoma with cardiac extension: excellent response with HB-94 chemotherapy protocol

A 10-month-old white infant presented with abdominal distention and bilateral scrotal hernia. Imaging studies of the abdomen and thorax showed a huge liver with multiple tumor masses and calcification involving all the segments. There was thrombosis in the inferior vena cava and right atrium. alpha-Fetoprotein was 246,000 IU/mL. HB-94 chemotherapy protocol was started at once due to rapid deterioration of the patient. Surgical biopsy performed after the first IPA (ifosfamide, cisplatin, doxorubicin) course showed hepatoblastoma with macrotrabecular variant. After a second IPA course and 2 courses of carboplatin and etoposide, the boy's clinical condition was excellent with normal alpha-fetoprotein but minimal regression and increased calcification in the tumor mass. Hepatic tumor was unresectable and no surgical intervention was performed. Transplantation could not be performed because of high morbidity and mortality. Despite general agreement that complete surgical resection is the cornerstone of treatment for patients with hepatoblastoma, the patient is in remission with 100% Karnofsky score in the 43 months of diagnosis.

Long-term glomerular filtration rate following pediatric liver transplantation

In adult patients a significant proportion of chronic renal failure after liver transplantation (LTX) has been described. This was attributed mainly to nephrotoxicity caused by Calcineurin inhibitors (CNI). If these results are transferable to pediatric patients was the aim of this study. Forty-five pediatric patients with a LTX performed between 1988 and 2003 were evaluated. Glomerular filtration rate was calculated using the Schwartz formula (calculated GFR (cGFR) (mL/min/1.73 m2) = kx height (cm)/serum creatinine (mg/dL)). Median age at LTX was 4 yr (range 0.3-18.1). Pretransplant median cGFR was significantly elevated with 157.5 mL/min/1.73 m2. Within the first 3 months after LTX median cGFR normalized to a median value of 102.7 (p < 0.05 vs. pretransplant cGFR). During long-term follow-up median cGFR remained stable with calculated values of 108.0 two years and 112.6 five years after transplantation. Using a linear and an exponential one compartment mathematical modeling of renal function the calculated GFR was stable even for very long observation times (n > 10 yr). Liver insufficiency prior to transplantation was associated with glomerular hyperfiltration. After successful liver transplantation cGFR normalized within the first 3 month and, in contrast to the reported GFR impairment in adult liver transplant recipients, remained stable, even in long-term follow-up.

Renal function following liver transplantation in children

The literature regarding the etiology and incidence of short and long-term renal functional impairment in pediatric liver allograft recipients was reviewed. Most of the reports include recipients receiving cyclosporine as the primary immunosuppressant. Using calculated glomerular filtration rate (cGFR), creatinine clearance or the serum creatinine level will lead to an overestimation of GFR. In contrast to data in adults, there are a limited number of pediatric recipients whose renal dysfunction has progressed to chronic kidney disease or end-state renal disease. Calcineurin inhibitors minimization has proven effective in reversing or preventing progressive deterioration of GFR; however, rejection episodes and complications have limited efficacy of this approach. Future multicenter studies using optimal GFR measurements are required to delineate the magnitude of renal dysfunction in pediatric recipients.

Liver transplantation for hepatoblastoma: indications and contraindications in the modern era

In the past 20 yr, a dramatic improvement has been achieved in the outcome of children with hepatoblastoma by combining cisplatin based chemotherapy and surgery. Treatment of patients in the USA is an exception to the rule that all patients should receive neoadjuvant chemotherapy. It is paramount that surgical resection be complete, both macro- and microscopically. Complete tumor resection can be achieved after chemotherapy with a partial hepatectomy when the intrahepatic extent is limited to 1-3 sectors. In multifocal (and solitary) hepatoblastomas invading all four liver sectors, and in centrally located tumors with close proximity to the major veins, the SIOPEL-1 study and an extensive review of the world experience have shown that primary transplantation provides high, long term, disease-free survival rate in the range of 80%. In contrast, the results of rescue transplants for incomplete tumor resection or disease recurrence after partial hepatectomy are disappointing (in the range of 30%). Hazardous attempts at partial hepatectomy in children with extensive hepatoblastoma should be discouraged. Guidelines are provided for early referral of children with extended hepatoblastoma to a transplant surgeon. There is a trend for a better patient survival after living related liver transplantation. Patients who will become candidates to liver transplantation should be treated with chemotherapy following the same protocols as for children undergoing a partial hepatectomy. There is a concern about cumulative nephrotoxicity of calcineurin inhibitors and chemotherapeutic drugs. Recent data suggest that these patients tolerate lower Tacrolimus trough blood levels than those transplanted for non-malignant conditions, without increasing the risk of acute rejection. Due to the rarity of the disease, these children should be treated in specialized centers.