Multifocal hepatoblastoma: is there a place for partial hepatectomy?

Surgical Management and Outcomes of Patients with Multifocal Hepatoblastoma

OBJECTIVE

To compare the outcomes of patients with multifocal hepatoblastoma (HB) treated at our institution with either orthotopic liver transplant (OLTx) or hepatic resection to determine outcomes and risk factors for recurrence.

BACKGROUND

Multifocality in HB has been shown to be a significant prognostic factor for recurrence and worse outcome. The surgical management of this type of disease is complex and primarily involves OLTx to avoid leaving behind microscopic foci of disease in the remnant liver.

METHODS

We performed a retrospective chart review on all patients <18 years of age with multifocal HB treated at our institution between 2000 and 2021. Patient demographics, operative procedure, post-operative course, pathological data, laboratory values, short- and long-term outcomes were analyzed.

RESULTS

A total of 41 patients were identified as having complete radiologic and pathologic inclusion criteria. Twenty-three (56.1%) underwent OLTx and 18 (43.9%) underwent partial hepatectomy. Median length of follow-up across all patients was 3.1 years (IQR 1.1-6.6 years). Cohorts were similar in rates of PRETEXT designation status identified on standardized imaging re-review (p = .22). Three-year overall survival (OS) estimate was 76.8% (95% CI: 60.0%-87.3%). There was no difference in rates of recurrence or overall survival in patients who underwent either resection or OLTx (p = .54 and p = .92 respectively). Older patients (>72 months), patients with a positive porta hepatis margin, and patients with associated tumor thrombus experienced worse recurrence rates and survival. Histopathology demonstrating pleomorphic features independently associated with worse rates of recurrence.

CONCLUSIONS

Through proper patient selection, multifocal HB was adequately treated with either partial hepatectomy or OLTx with comparable outcome results. HB with pleomorphic features, increased patient age at diagnosis, involved porta hepatis margin on pathology, and the presence of associated tumor thrombus may be associated with worse outcomes regardless of the local control surgery offered.

LEVEL OF EVIDENCE

III.

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.

Multifocal hepatoblastoma: What is the risk of recurrent disease in the remnant liver?

PURPOSE

Multifocal hepatoblastoma (HB) is often treated with total hepatectomy and transplantation owing to concerns of surgical resectability, local recurrence, and/or metachronous tumor in the remnant liver. We aimed to review HB patients to determine the risk of local recurrence in multifocal disease.

METHODS

We undertook retrospective cohort analysis of all HB patients at a single tertiary referral center between 2001 and 2015. Demographics, diagnostic features, operative details, and outcomes were analyzed.

RESULTS

Sixty patients underwent surgical management of HB. 39 had unifocal, and 21 had multifocal disease. Of multifocal patients, 9 underwent liver transplantation, 10 anatomic resections, and 2 nonanatomic resections. Overall, two patients had recurrence in the remnant liver - both from the unifocal group. There were equivalent distant (lung) recurrences between the groups (8% for unifocal versus 14% for multifocal), p = 0.89. At a mean of 75 months of follow-up, overall survival was 97% for unifocal patients and 86% for multifocal patients, p = 0.12.

CONCLUSION

Multifocal HB was not associated with increased local recurrence in the setting of R0 resection and chemotherapy. These data do not support the contention that all patients with multifocal HB require a total hepatectomy and transplantation to reduce the incidence of local recurrence and/or metachronous tumor development.

LEVEL OF EVIDENCE

Level III - Limited cohort analysis.

2017 PRETEXT: radiologic staging system for primary hepatic malignancies of childhood revised for the Paediatric Hepatic International Tumour Trial (PHITT)

Imaging is crucial in the assessment of children with a primary hepatic malignancy. Since its inception in 1992, the PRETEXT (PRE-Treatment EXTent of tumor) system has become the primary method of risk stratification for hepatoblastoma and pediatric hepatocellular carcinoma in numerous cooperative group trials across the world. The PRETEXT system is made of two components: the PRETEXT group and the annotation factors. The PRETEXT group describes the extent of tumor within the liver while the annotation factors help to describe associated features such as vascular involvement (either portal vein or hepatic vein/inferior vena cava), extrahepatic disease, multifocality, tumor rupture and metastatic disease (to both the lungs and lymph nodes). This manuscript is written by members of the Children's Oncology Group (COG) in North America, the International Childhood Liver Tumors Strategy Group (SIOPEL) in Europe, and the Japanese Study Group for Pediatric Liver Tumor (JPLT; now part of the Japan Children's Cancer Group) and represents an international consensus update to the 2005 PRETEXT definitions. These definitions will be used in the forthcoming Trial to Pediatric Hepatic International Tumor Trial (PHITT).

Pediatric liver transplantation for hepatoblastoma

Hepatoblastoma is the most common pediatric liver tumor and is usually diagnosed before five years of age. Treatment consists of a combination of chemotherapy and surgery, with the goal being attainment of complete local control by surgical resection and eradication of any extrahepatic disease. Neoadjuvant chemotherapy is utilized and is often beneficial in rendering tumors resectable; however, prolonged chemotherapy administration attempting to render tumors resectable by conventional resection should be avoided. For patients whose tumors are too extensive to be conventionally resected, liver transplantation can be curative and remains the treatment of choice for eligible patients otherwise incurable by conventional resection.

PRETEXT II-III multifocal hepatoblastoma: significance of resection of satellite lesions irrespective of their disappearance after chemotherapy

PURPOSE

To determine the outcomes of resection of satellite lesions in PRE-treatment Tumor EXTension (PRETEXT) II and III multifocal hepatoblastoma irrespective of their disappearance after chemotherapy. To compare the overall outcomes of multifocal and unifocal hepatoblastoma.

METHODS

Fourteen patients with PRETEXT II (n = 7) and III (n = 7) multifocal hepatoblastoma treated between April 2006 and July 2014 were analyzed and their outcomes were compared with PRETEXT II and III unifocal hepatoblastoma treated in the similar period.

RESULTS

Satellite lesion or the affected segments with disappeared satellite lesions were resected in 11 patients. Amongst them, all relapses were distant except one in the liver. In contrast, two of three patients developed liver relapse when the affected segments were not resected. None of the patients receiving intensive chemotherapy based on SIOPEL-3 guidelines developed a relapse. The 3-year event-free and overall survival were 38.6 and 42.9% in multifocal hepatoblastoma and 86.4 and 92.4% in unifocal hepatoblastoma (p = 0.001). Multifocality (p = 0.002) and AFP >10,000 after induction chemotherapy significantly affected event-free survival (p = 0.01).

CONCLUSION

Multifocal hepatoblastoma is associated with poor outcomes as compared to unifocal hepatoblastoma. These preliminary observations of relapse and the role of chemotherapy intensification deserve further study in a multicenter controlled trial setting.

Is multifocality a prognostic factor in childhood hepatoblastoma?

BACKGROUND

The aim of this study was to assess the prognostic value of multifocality and the effectiveness of two different therapeutic strategies in patients with newly diagnosed hepatoblastoma.

PROCEDURES

Between 1998 and 2011, 31 patients diagnosed with hepatoblastoma were referred to Ospedale Papa Giovanni XXIII, Bergamo, Italy. Patients were stratified according to SIOPEL protocols into high-risk (HR if AFP <100 ng/mL and/or PRETEXT IV and/or vascular invasion and/or extra-hepatic intra-abdominal disease and/or metastases) and standard-risk (SR, all others). The patient data we evaluated were: multifocality; patient age; gender; platelet count; AFP level at diagnosis, during treatment and follow-up; histotype; gestational age; birth weight; surgery (either resection or transplantation) and chemotherapy regimen adopted before and after surgery. The outcome measures were event free survival (EFS) and overall survival (OS); survival curves were estimated according to Kaplan-Meier.

RESULTS

EFS and OS were associated significantly with multifocality (3-year EFS 40% vs. 95%, P = 0.006; 3-year OS 42% vs. 95%, P = 0.004). Multivariate analysis demonstrated that multifocality predicts lower EFS (hazard ratio 10.01, P = 0.007). Other factors at diagnosis did not reach statistical significance. A marked treatment dependent improvement was associated with intensive chemotherapy given both before and after liver transplantation (P = 0.06).

CONCLUSIONS

Patients diagnosed with multifocal tumors had lower EFS levels. Multifocality should be taken into account for future stratification and further studied to assess genetic profile, immunochemistry and prognostic role.

Surgical treatment of hepatoblastoma

Surgical resection remains the cornerstone of cure in hepatoblastoma (HB). Meticulous review of contrast enhanced CT/MR imaging facilitates PRETEXT and POST-TEXT grouping to determine optimal timing and desired extent of liver resection. Excellent knowledge of liver anatomy is essential and the dissection must ensure protection of the vascular inflow and outflow to the remaining liver at all times. Referral to a liver specialty center in advanced cases may facilitate resectability. Potential surgical complications include bleeding, vascular injury, cardiac arrest, liver failure, and bile leak. The risk of complications can be minimized with preoperative planning, appropriate referral, and precise surgical technique.

Adult hepatoblastoma: learning from children

Hepatoblastoma is the most common malignant liver tumour in infants and young children. Its occurrence in the adult population is debated and has been questioned. The aim of this paper is to review the histological and clinical features of adult hepatoblastoma as described in the adult literature, and to compare the findings with those of paediatric hepatoblastoma. The developmental and molecular aspects of hepatoblastoma are reviewed and their potential contribution to diagnosis of adult hepatoblastoma discussed. Case reports of adult hepatoblastoma identified by a PubMed search of the English, French, German, Italian, and Spanish literature through March 2011 were reviewed. Forty-five cases of hepatoblastoma were collected. Age at presentation was variable. Survival was uniformly poor, except for the rare patients who presented with the relatively differentiated, foetal type. The common denominator between adult and paediatric cases is the occurrence of embryonal or immature aspect of the tumours. Whether the adult cases of hepatoblastoma represent blastemal tumours, stem cell tumours, or unusual differentiation patterns in otherwise more frequent adult liver tumours remains to be established. Adult tumours labelled as hepatoblastoma are characterised by malignant appearing mesenchymal components. Surgical management is the cornerstone of therapy in children and also appears to confer an improved prognosis in adults. Whether adult hepatoblastoma exists, remains controversial. Indeed, several features described in adult cases are markedly different from hepatoblastoma as it is understood in children, and other differential diagnoses should also be entertained. Nonetheless, hepatoblastoma should be considered in adults presenting with primary liver tumours in the absence of pre-existing liver disease. Adult and paediatric patients with immature hepatoblastoma appear to have worse outcomes, and adults presenting with presumed hepatoblastoma have an overall poorer prognosis than children with hepatoblastoma. In all patients, surgery should be the treatment of choice, neoadjuvant chemotherapy is advisable.

Successful nontransplant resection of POST-TEXT III and IV hepatoblastoma

BACKGROUND

Liver transplantation is increasingly advocated as primary surgical therapy for children with hepatoblastoma involving 3 or 4 sectors of the liver after neoadjuvant chemotherapy. This study evaluated the results of nontransplant hepatectomy in children who might otherwise have been considered for liver transplantation.

METHODS

All children who underwent resection at a single institution from 1998 to 2009 for POST-TEXT IV or centrally located POST-TEXT III hepatoblastoma after neoadjuvant chemotherapy were reviewed.

RESULTS

Fourteen children (7 boys) with a median age of 8 months at diagnosis met study criteria. Pulmonary metastases in 3 patients were resected in 2 and resolved with chemotherapy in 1 patient. Preoperative grouping after neoadjuvant chemotherapy was POST-TEXT IV in 3 patients and POST-TEXT III in 11 patients. Thirteen of 14 (93%) children who underwent aggressive resection despite being potential candidates for primary transplantation were alive and tumor-free with a median follow-up of 57 months. Observed survival rates at 1, 2, and 5 years were 93%, 91%, and 88% respectively. Event-free survival rates at 1, 2, and 5 years were 93%, 91%, and 75%, respectively.

CONCLUSIONS

Excellent survival (93%) was obtained with aggressive resection in children with POST-TEXT III and IV hepatoblastoma meeting criteria for transplant referral. The 1 death occurred in a patient with unfavorable small cell histology. These children should be managed at institutions experienced in both advanced pediatric hepatobiliary surgery and transplantation. Operative exploration was frequently required to ultimately determine which tumors can be resected and which require transplantation.

Cure of multifocal panhepatic hepatoblastoma: is liver transplantation always necessary?

PURPOSE

Multifocal panhepatic hepatoblastoma (HB) without extrahepatic disease is generally considered as an indication for total hepatectomy and liver transplantation. However, after initial chemotherapy, downstaging of the tumor sometimes allows complete macroscopic resection by partial hepatectomy. This procedure is no longer recommended because of the risk of persistent viable tumor cells in the hepatic remnant. We report our experience with conservative surgery in such cases.

METHOD

Between 2000 and 2005, 4 children were consecutively referred to our unit with multinodular pan-hepatic HBs (classification PRETEXT IV of the International Society of Pediatric Oncology Liver Tumor Study Group SIOPEL). Three of them had extrahepatic disease at diagnosis. All patients were treated according to SIOPEL 3 and 4 protocols.

RESULTS

Extrahepatic metastases were still viable in 2 of 3 patients after initial chemotherapy. These patients eventually died of tumor recurrence. In the 2 patients without residual extrahepatic disease, liver tumors had regressed, and complete macroscopic excision of hepatic tumor remnants could be achieved by conservative surgery. These 2 children are alive and well and free of tumor 7 years after diagnosis.

CONCLUSIONS

Conservative surgery may be curative in some multinodular PRETEXT IV HB patients, with a good response to preoperative chemotherapy and complete excision of all macroscopic tumor remnants. However, because of the lack of reliable predictors of sterilization of the microscopic disease in the residual liver, with subsequent poor prognosis, total hepatectomy and liver transplantation remain currently recommended in patients with multinodular PRETEXT IV HB without extrahepatic disease, even though some of these children are probably overtreated.

Progress in the surgical treatment of malignant liver tumors in children

During the last decade, important progress has been made in the surgical treatment of malignant liver tumors in children. For hepatoblastoma, there is a general consensus for combining surgical resection with neoadjuvant (and adjuvant) chemotherapy. Long-term disease-free survival of around 85-90% can be achieved for resectable HB involving no more than three sections of the liver (PRETEXT I-III). For unresectable HB without extrahepatic invasion (PRETEXT IV with involvement of all four sections and some cases of PRETEXT III with invasion of, or close contact with major venous structures), similar results can be obtained with total hepatectomy and liver transplantation. For hepatocellular carcinoma, most often without underlying liver disease in children of the western world, results of resection with partial hepatectomy remain dismal, due to a high rate of recurrence. In contrast, remarkable survival rates have been obtained during the last decade with liver transplantation. There is no argument, either biological or based on evidence, that the selection of pediatric candidates for transplantation should be based on the same criteria as in adult patients (the Milan criteria). Optimization of results require to concentrate children with a malignant liver tumors in specialized, multidisciplinary pediatric centers with expertise in chemotherapy and in both major liver resections and transplantation. Enrolling these children in prospective trials should be encouraged, as well as prospective registration of transplanted patients in PLUTO (Pediatric Liver Unresectable Tumor Observatory-http://Pluto.cineca.org) in order to clarify issues unresolved by retrospective studies.

Tumors of the liver in children

In this review we examine the diagnosis and treatment of pediatric liver tumors- both malignant and benign. The two most common malignant tumors are hepatoblastoma and hepatocellular carcinoma. Hepatoblastoma is seen in younger children, hepatocellular carcinoma in older children. Other malignant liver tumors are quite rare and include biliary rhabdomyosarcoma, angiosarcoma, rhabdoid tumor, and undifferentiated sarcoma. The commonly seen benign liver tumors in children are infantile hemangioma, mesenchymal hamartoma, and focal nodular hyperplasia. Rare benign tumors are hepatic adenoma, which is occasionally seen in teenage girls, and teratoma which is a very rare liver tumor in infants.

The role of liver transplantation in the management of paediatric liver tumours

In recent years, considerable progress has been made in the treatment of children with hepatoblastoma largely due to effective pre-operative chemotherapy. Total hepatectomy and liver transplantation has emerged as an effective treatment for the small proportion of children with unresectable hepatoblastoma limited to the liver. A 5-year survival of 70% can be achieved in such cases. In contrast, the results of liver transplantation in children with hepatocellular cancer remain poor because these tumours are usually advanced with evidence of major vascular invasion and/or extrahepatic spread at the time of presentation. An exception is those children in whom the hepatocellular carcinoma is detected during surveillance of chronic liver disease - they typically have smaller tumours and frequently have a good prognosis after liver transplantation. The role of liver transplantation in children with other primary hepatic malignancies remains uncertain because experience is very limited. Liver transplantation is rarely needed in the management of children with benign liver tumours but, if other treatments have failed, it can be a life-saving intervention.

Features predicting unresectability in hepatoblastoma

BACKGROUND

Approximately 20% of patients who have hepatoblastoma (HB) still have unresectable disease after preoperative chemotherapy (POC). In these circumstances, orthotopic liver transplantation (OLT) should be performed 1 month after POC. The authors sought to identify presenting features that would predict unresectability in patients with HB and to provide suggestions for early referral and listing for OLT.

METHODS

Notes, radiology films, and histology from patients who were treated over the previous 20 years were reviewed. Unfeasible resection was defined by bilobar involvement, vascular extension, and metastatic disease after POC. Failed conservative treatment (FCT) was used to categorize patients who were not disease-free with their native liver > or =1 year after surgery.

RESULTS

Of 28 patients who were studied, 14 patients underwent resection, and 10 patients required OLT. Four patients did not undergo any type of surgery because of tumor progression. Overall, the 5-year survival rate was 76% (95% confidence interval, 54.8-89%). Predictors of FCT were multifocality (P = .006), a high pretreatment extent of tumor (PRETEXT) score (III or IV; P = .006), portal vein involvement (P = .02), hepatic vein involvement (P = .02), or vena cava involvement (P = .05). Patients who achieved a curative resection presented at a younger age (median, 0.7 years vs 4.2 years, P = .02). Patients who had multifocal lesions and those who had an alpha-fetoprotein (alphaFP) level <100 ng/mL survived only if they underwent transplantation.

CONCLUSIONS

Patients with HB who were managed by combined chemotherapy and surgery has a high survival rate. Older patients who had multifocal tumors, high PRETEXT scores, involvement of major liver vessels, and alphaFP levels <100 ng/mL were less likely to achieve curative resection. These findings at presentation should lead the clinicians to liaise early with a transplantation center.

The contribution of transplantation to the treatment of liver tumors in children

Major progress has been achieved during the last decades in the treatment of malignant liver tumors in children, both in chemotherapy and surgical management. Chemosensitivity varies between tumor types, and radical resection remains essential to effect a cure. In tumors extensively involving a normal liver, in a diffuse or multifocal manner, radical resection cannot be accomplished with a partial hepatectomy. This has been the case for some instances of advanced hepatoblastoma and epithelioid hemangioendothelioma. In hepatoblastoma, current experience shows that results of primary liver transplantation with neoadjuvant chemotherapy are excellent with around an 80% 5-to-10-year disease-free survival rate. Epithelioid hemangioendothelioma is very rarely seen in children and may have a more malignant behavior than in adult patients, and liver transplantation may not be the best management option. In nonresectable hepatocellular carcinoma (HCC) developed on an otherwise normal liver, the results of liver transplantation are similarly poor to those obtained in adult patients, except in a few highly selected series fulfilling the Milano criteria. The experience with HCC is still very scarce in children. Incidental HCC associated with chronic liver disease does not seem to impact posttransplant survival. When they are symptomatic, however, indications for transplantation should be very selective regarding tumor size, multi-focality, vascular invasion and distant metastases.

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.

Guidelines for surgical treatment of hepatoblastoma in the modern era--recommendations from the Childhood Liver Tumour Strategy Group of the International Society of Paediatric Oncology (SIOPEL)

Cisplatin-containing chemotherapy and complete surgical resection are both crucial in the cure of hepatoblastoma. Radical resection can be obtained either conventionally by partial hepatectomy or with orthotopic liver transplant, but the surgical approach to hepatoblastoma differs considerably across the world. Our main aim in this paper is to present the surgical recommendations of the Childhood Liver Tumour Strategy Group of the International Society of Paediatric Oncology (SIOPEL), as well as to stimulate international debate on this issue. We discuss biopsy, verification of resectability, resection principles, indications and potential contraindications for orthotopic liver transplant, as well as thoracic surgery for pulmonary metastases. We suggest that heroic liver resections with a high probability of leaving residual tumour should be avoided whenever possible. In such cases primary orthotopic liver transplant should be considered. Superior survival rates in hepatoblastoma patients who have received a primary transplant after a good response to chemotherapy support the strategy of avoiding partial hepatectomy in cases where radical resection appears difficult and doubtful. We recommend early referral to a transplant surgeon in cases of: (i) multifocal or large solitary PRETEXT IV (PRE Treatment EXTent of disease scoring system) hepatoblastoma involving all four sectors of the liver and (ii) unifocal, centrally located tumours involving main hilar structures or main hepatic veins. Because complete tumour resection is a prerequisite for cure, any strategy leading to an increased resection rate will result in improved survival. We advise the more frequent use of orthotopic liver transplant, as well as the standardisation of techniques for partial liver resection. These guidelines should not be seen as final, but rather as a starting point for further discussion between the various national and international liver tumour study groups.