Transplantation for unresectable liver tumors in children

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.

Malignant liver tumors

Malignant tumors of the liver comprise a relatively small fraction of the total number of pediatric malignancies. However, these tumors can be a significant cause of morbidity and mortality, and there have been significant therapeutic gains during the past few decades through advances in systemic therapy and surgical treatment. Even in patients with advanced local disease, complete resection is now a possibility because of improvements in liver transplantation techniques. In this review, we will discuss the staging and treatment of common malignant tumors of the liver.

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.

Successful orthotopic liver transplantation for treatment of a hepatic yolk sac tumor

Yolk sac tumors (YSTs) represent 3% of malignancies in childhood and most commonly arise in the gonads. Hepatic YSTs are rare and previous reported cases were treated with resection and/or chemotherapy with mixed results. We present the first case of an unresectable hepatic YST in a 2-year-old boy treated successfully with liver transplantation.

Liver transplantation for hepatoblastoma: results from the International Society of Pediatric Oncology (SIOP) study SIOPEL-1 and review of the world experience

BACKGROUND

For hepatoblastoma (HB) that remains unresectable by partial hepatectomy after chemotherapy, total hepatectomy with orthotopic liver transplantation (LTX) has been advocated as the best treatment option. The role of LTX in the overall management of HB is still, however, unclear.

PROCEDURE

The results of LTX from the first study of HB by the International Society of Pediatric Oncology, SIOPEL-1, were analyzed. In addition, the world experience of LTX for HB was extensively reviewed. Twelve patients in the SIOPEL-1 study underwent a LTX. Median (range) follow-up at Dec. 31, 2001 was 117 months (52-125) since LTX.

RESULTS

Overall survival at 10 years post-LTX was 85% for the seven children who received a "primary LTX" and 40% for the 5 children who underwent a "rescue LTX" after previous partial hepatectomy. In the world experience (147 cases), the overall survival rate at 6 year post-LTX was 82% for 106 patients who received a "primary LTX" and 30% for 41 patients who underwent a "rescue LTX." Multivariate analysis of patients undergoing primary LTX showed that only macroscopic venous invasion had a significant impact (P-value: 0.045 with a hazard ratio of 2.96) on overall survival.

CONCLUSIONS

Orthotopic LTX has added a new dimension to the treatment of HB unresectable by partial hepatectomy. Because of the rarity of the disease and to optimize results, children with extensive HB should be treated in centers with surgical expertise in pediatric major liver resection and LTX, in close collaboration with pediatric oncologists, radiologists, and histopathologists.

Renal function following liver transplantation for unresectable hepatoblastoma

Combination of cyclosporine (CsA) and tacrolimus immunosuppression post-liver transplantation (LT) and the chemotherapeutic drugs used to treat hepatoblastoma (HB), are nephrotoxic. We aimed to determine the severity and duration of nephrotoxicity in children following LT for unresectable HB. We reviewed all children undergoing LT for unresectable HB at the Liver Unit, Birmingham Children's Hospital, UK, from 1991 to July 2000. Thirty-six children undergoing LT for biliary atresia, matched for age and sex, were selected as controls to compare pre- and post-LT renal function. Renal function was determined by estimation of glomerular filtration rate (eGFR) derived from plasma creatinine using Schwartz's formula. Twelve children with HB (mean age of diagnosis 33 months) who underwent LT (mean age 47 months) and 36 controls (mean age of LT 34 months) were studied. CsA was the main immunosuppressive drug used in each group. The median eGFR before, and at 3, 6, 12, 24 and 36 months after LT in HB group was significantly lower than controls (93 vs. 152, 66 vs. 79, 62 vs. 86, 66 vs. 87, 64 vs. 94, 53 vs. 90 mL/min/1.73 m2, respectively; 0.01 < p < 0.03). The reductions in the median eGFR of both the HB group and controls before and at 36 months after LT were 49 and 41%, respectively. At 36 months after LT, there was a trend for partial recovery of the eGFR in the controls but not in the HB group. Children who underwent LT for unresectable HB had renal dysfunction before transplantation that persisted for 36 months after LT.

Current status of liver tumors in children

Most tumors of the liver in children are malignant. Benign tumors occur most often in infants, are usually vascular, and seldom require surgery. Hepatoblastoma and hepatocellular carcinoma are the most common malignant tumors. Hepatoblastoma affects younger children and hepatocellular carcinoma affects older children and adolescents. Treatment consists of surgical resection before or after chemotherapy, and long-term survival is impossible without resection. Survival rate exceeds 80% in children with hepatoblastoma. Children with hepatocellular carcinoma and other more unusual malignant tumors do not do as well. Current treatment plans are described for both benign and malignant tumors of the liver.

Surgical resection and chemotherapy improve survival rate for patients with hepatoblastoma

BACKGROUND

The authors reviewed retrospectively their experience in 30 children with hepatoblastoma (HB). Despite an increased trend in the incidence of HB during the last 2 decades, an encouraging cure rate has been achieved with complete resection of the tumor and chemotherapy before or after surgery with cisplatin plus doxorubicin (Adriamycin) or cisplatin plus vincristine plus 5-Fluorouracil.

RESULTS

There were 10 female and 20 male patients. For the period from 1963 to 1980 there were 8 patients, and for the period from 1981 to 1998 there were 22 patients. Their mean age at surgery was 16 months (range, 3.5 months to 5.5 years). Tumors were localized to the right lobe in 10 (42%), to the left lobe in 7 (29%), and in both lobes in 7 (29%) of the resected patients. Tumors were greater than 10 cm in size in 16 (67%) of these patients. Twenty-four patients (80%), underwent liver resection before or after chemotherapy. One patient (3%) with an unresectable tumor received chemotherapy and a liver transplant. In 5 patients (17%) the hepatic involvement was too extensive for resection. The types of resection performed were right lobectomy in 7, left lobectomy in 6, right trisegmentectomy in 8, left trisegmentectomy in 2, and middle hepatectomy in 1. The overall survival rate for 35 years of the study was 60% (18 of 30). With the association of surgery and chemotherapy (1981 through 1998) survival rate is 82% (14 of 17). Overall median follow-up in our study is 8 years (range, 2.5 to 24 years).

CONCLUSIONS

There has been a dramatic improvement in the results of treatment of hepatoblastoma. Formerly, only 25% to 30% of patients were cured, whereas today, with combination of chemotherapy and surgery, 75% to 80% may be cured.

Liver tumors

Liver tumors in children are rare, potentially complex, and encompass a broad spectrum of disease processes. Any age group may be affected, including the fetus. Most present with abdominal distension and/or a mass. Accurate preoperative diagnosis is usually possible using a combination of ultrasound scanning and cross-sectional imaging techniques (CT and/or MR), supplemented by liver biopsy and measurement of tumor markers. The most common benign tumors are hemangiomas, but mesenchymal hamartoma, focal nodular hyperplasia, and adenoma also are found. In Western countries, hepatoblastoma is the most common primary malignant liver tumor; disease-free survival is now possible in more than 80% of affected patients because of advances in combination chemotherapy, improved techniques of surgical resection, and the selective use of liver transplantation. In contrast, there has been less progress in the management of hepatocellular cancer, which still poses many therapeutic challenges.

Liver transplantation. The pediatric challenge

Successful liver transplantation in a child is often a hard-won victory, requiring all the combined expertise of a dedicated pediatric transplant team. This article outlines the considerable challenges still facing pediatric liver transplant physicians and surgeons. In looking to the future, where should priorities lie to enhance the success already achieved? First, solutions to the donor shortage must be sought aggressively by increasing the use of from split-liver transplants, judicious application of living-donor programs, and increasing the donation rate, perhaps by innovative means. The major immunologic barriers, to successful xenotransplantation make it unlikely that this option will be tenable in the near future. Second, current immunosuppression is nonspecific, toxic, and unable to be individually adjusted to the patient's immune response. The goal of achieving donor-specific tolerance will require new consideration of induction protocols. Developing a clinically applicable method to measure the recipient's immunoreactivity is of paramount importance, for future studies of new immunosuppressive strategies and to address the immediate concern of long-term over-immunosuppression. The inclusion of pediatric patients in new protocols will require the ongoing insistence of pediatric transplant investigators. Third, the current immunosuppressive drugs have a long-term morbidity and mortality of their own. These long-term effects are particularly important in children who may well have decades of exposure to these therapies. There is now some understanding of their long-term renal toxicity and the risk of malignancy. New drugs may obviate renal toxicity, whereas the risk of malignancy is inherent in any nonspecific immunosuppressive regimen. Although progress is being made in preventing and recognizing PTLD, this entity remains an important ongoing concern. The global effect of long-term immunosuppression on the child's growth, development, and intellectual potential is unknown. Of particular concern is the potential for neurotoxicity from the calcineurin inhibitors. Fourth, recurrent disease and new diseases, perhaps potentiated by immunosuppressive drugs, must be considered. Already the recurrence of autoimmune disease and cryptogenic cirrhosis have been documented in pediatric patients. Now, a new lesion, a nonspecific hepatitis, sometimes with positive autoimmune markers, that may progress to cirrhosis has been recognized. It is not known whether this entity is an unusual form of rejection, an unrecognized viral infection, or a response to immunosuppressive drugs themselves. Finally, pediatric transplant recipients, like any other children, must be protected and nourished physically and mentally if they are to fulfill their potential. After liver transplantation the child's growth, intellectual functioning, and psychologic adaptation may all require special attention from parents, teachers, and physicians alike. There is limited understanding of how the enormous physical intervention of a liver transplantation affects a child's cognitive and psychologic function as the child progresses through life. The persons caring for these children have the difficult responsibility of providing services to evaluate these essential measures of children's health over the long term and to intervene if necessary. Part of the transplant physician's our duty to protect and advocate for children is to fight for equal access to health care. In most of the developing world, economic pressures make it impossible to consider liver transplantation a health care priority. In the United States and in other countries with the medical infrastructure to support liver transplantation, however, health care professionals must strive to be sure that the policies governing candidacy for transplantation and allocation of organs are applied justly and uniformly to all children whose lives are threatened by liver disease. In the current regulatory climate that increasingly takes medical decisions out of the hands of physicians, pediatricians must be even more prepared to protect the unique and often complicated needs of children both before and after transplantation. Only in this way can the challenges of the present and the future be met.

A new technique for resecting 'unresectable' liver tumors

BACKGROUND/PURPOSE

Liver tumors that surround the three major hepatic veins traditionally have been considered unresectable. This report describes an extended atypical left hepatectomy technique for tumors around the major hepatic veins.

METHODS

Three children with tumors surrounding the 3 hepatic veins underwent intraoperative evaluation for extended atypical left hepatectomy. The left hepatic artery, left branch of the portal vein, and the 3 hepatic veins are occluded with vascular clamps. Perfusion of the remaining liver is through the right hepatic artery and portal vein into the retrohepatic vena cava via the retro hepatic veins. If the liver remains soft and does not become mottled, division of the 3 hepatic veins and resection of the tumor are carried out.

RESULTS

Extended atypical left hepatectomy was successful in 2 children. Bile leak occurred in 1 instance and healed spontaneously. Both patients had transiently elevated serum bilirubin and transaminase levels and an elevated prothrombin time for 2 weeks. Both survived after treatment with chemotherapy. In the third child the liver became tense and mottled, and the procedure was abandoned.

CONCLUSIONS

Successful extended atypical left hepatectomy depends on the ability of the retro hepatic veins to adequately drain blood into the vena cava after interruption (clamping) of the main hepatic veins. If the liver becomes mottled and tense the procedure must be abandoned and the patient should be considered for hepatic transplantation.

Pediatric liver tumors

An infant or child who presents with a large intrahepatic mass will most likely have a malignant tumor. In children, benign tumors constitute only 30% of liver tumors and most are vascular in origin. Treatment of benign vascular tumors is conservative and seldom surgical. Hepatoblastoma is the most common malignant tumor followed by hepatocellular carcinoma. Treatment of malignant tumors is based on a combination of surgery and chemotherapy. Children with hepatic malignancies that can be resected have an excellent prognosis. Other rare benign and malignant tumors of the liver do occur and surgery plays a critical role in management.