Cisplatin chemotherapy and surgery are effective treatments for children with standard-risk hepatoblastoma but may cause considerable and irreversible hearing loss. This trial compared cisplatin with cisplatin plus delayed administration of sodium thiosulfate, aiming to reduce the incidence and severity of cisplatin-related ototoxic effects without jeopardizing overall and event-free survival. We randomly assigned children older than 1 month and younger than 18 years of age who had standard-risk hepatoblastoma (≤3 involved liver sectors, no metastatic disease, and an alpha-fetoprotein level of >100 ng per milliliter) to receive cisplatin alone (at a dose of 80 mg per square meter of body-surface area, administered over a period of 6 hours) or cisplatin plus sodium thiosulfate (at a dose of 20 g per square meter, administered intravenously over a 15-minute period, 6 hours after the discontinuation of cisplatin) for four preoperative and two postoperative courses. The primary end point was the absolute hearing threshold, as measured by pure-tone audiometry, at a minimum age of 3.5 years. Hearing loss was assessed according to the Brock grade (on a scale from 0 to 4, with higher grades indicating greater hearing loss). The main secondary end points were overall survival and event-free survival at 3 years. A total of 109 children were randomly assigned to receive cisplatin plus sodium thiosulfate (57 children) or cisplatin alone (52) and could be evaluated. Sodium thiosulfate was associated with few high-grade toxic effects. The absolute hearing threshold was assessed in 101 children. Hearing loss of grade 1 or higher occurred in 18 of 55 children (33%) in the cisplatin–sodium thiosulfate group, as compared with 29 of 46 (63%) in the cisplatin-alone group, indicating a 48% lower incidence of hearing loss in the cisplatin–sodium thiosulfate group (relative risk, 0.52; 95% confidence interval [CI], 0.33 to 0.81; P=0.002). At a median of 52 months of follow-up, the 3-year rates of event-free survival were 82% (95% CI, 69 to 90) in the cisplatin–sodium thiosulfate group and 79% (95% CI, 65 to 88) in the cisplatin-alone group, and the 3-year rates of overall survival were 98% (95% CI, 88 to 100) and 92% (95% CI, 81 to 97), respectively. The addition of sodium thiosulfate, administered 6 hours after cisplatin chemotherapy, resulted in a lower incidence of cisplatin-induced hearing loss among children with standard-risk hepatoblastoma, without jeopardizing overall or event-free survival. (Funded by Cancer Research UK and others; SIOPEL 6 ClinicalTrials.gov number, NCT00652132; EudraCT number, 2007-002402-21.)

Liver tumors are rare in children, and their diagnoses may be challenging particularly because of the lack of a current consensus classification system. Systematic central histopathological review of these tumors performed as part of the pediatric collaborative therapeutic protocols has allowed the identification of histologic subtypes with distinct clinical associations. As a result, histopathology has been incorporated within the Children’s Oncology Group (COG) protocols, and only in the United States, as a risk-stratification parameter and for patient management. Therefore, the COG Liver Tumor Committee sponsored an International Pathology Symposium in March 2011 to discuss the histopathology and classification of pediatric liver tumors, and hepatoblastoma in particular, and work towards an International Pediatric Liver Tumors Consensus Classification that would be required for international collaborative projects. Twenty-two pathologists and experts in pediatric liver tumors, including those serving as central reviewers for the COG, European Société Internationale d’Oncologie Pédiatrique, Gesellschaft für Pädiatrische Onkologie und Hämatologie, and Japanese Study Group for Pediatric Liver Tumors protocols, as well as pediatric oncologists and surgeons specialized in this field, reviewed more than 50 pediatric liver tumor cases and discussed classic and newly reported entities, as well as criteria for their classification. This symposium represented the first collaborative step to develop a classification that may lead to a common treatment-stratification system incorporating tumor histopathology. A standardized, clinically meaningful classification will also be necessary to allow the integration of new biological parameters and to move towards clinical algorithms based on patient characteristics and tumor genetics, which should improve future patient management and outcome.

The objective of this study was to establish the efficacy and safety of a new treatment regimen consisting of dose-dense cisplatin-based chemotherapy and radical surgery in children with high-risk hepatoblastoma. SIOPEL-4 was a prospective single-arm feasibility study. Patients aged 18 years or younger with newly diagnosed hepatoblastoma with either metastatic disease, tumour in all liver segments, abdominal extrahepatic disease, major vascular invasion, low α fetoprotein, or tumour rupture were eligible. Treatment consisted of preoperative chemotherapy (cycles A1-A3: cisplatin 80 mg/m(2) per day intravenous in 24 h on day 1; cisplatin 70 mg/m(2) per day intravenous in 24 h on days 8, 15, 29, 36, 43, 57, and 64; and doxorubicin 30 mg/m(2) per day intravenous in 24 h on days 8, 9, 36, 37, 57, and 58) followed by surgical removal of all remaining tumour lesions if feasible (including liver transplantation and metastasectomy, if needed). Patients whose tumour remained unresectable received additional preoperative chemotherapy (cycle B: doxorubicin 25 mg/m(2) per day in 24 h on days 1-3 and 22-24, and carboplatin area under the curve [AUC] 10·6 mg/mL per min per day intravenous in 1 h on days 1 and 22) before surgery was attempted. After surgery, postoperative chemotherapy was given (cycle C: doxorubicin 20 mg/m(2) per day in 24 h on days 1, 2, 22, 23, 43, and 44, and carboplatin AUC 6·6 mg/mL per min per day in 1 h on days 1, 22, and 43) to patients who did not receive cycle B. The primary endpoint was the proportion of patients with complete remission at the end of treatment. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00077389. We report the final analysis of the trial. 62 eligible patients (39 with lung metastases) were included and analysed. 60 (98%, 95% CI 91-100) of 61 evaluable patients (one child underwent primary hepatectomy) had a partial response to preoperative chemotherapy. Complete resection of all tumour lesions was achieved in 46 patients (74%). At the end of therapy, 49 (79%, 95% CI 67-88) of 62 patients were in complete remission. With a median follow-up of 52 months, 3-year event-free survival was 76% (95% CI 65-87) and 3-year overall survival was 83% (73-93). 60 (97%) patients had grade 3-4 haematological toxicity (anaemia, neutropenia, or thrombocytopenia) and 44 (71%) had at least one episode of febrile neutropenia. Other main grade 3 or 4 toxicities were documented infections (17 patients, 27%), anorexia (22, 35%), and mucositis (seven, 11%). One child died of fungal infection in neutropenia. Moderate-to-severe ototoxicity was documented in 31 (50%) patients. 18 serious adverse events (including two deaths) reflecting the observed side-effects were reported in the trial (the most common was ototoxicity in five patients). The SIOPEL-4 treatment regimen is feasible and efficacious for complete remission at the end of treatment for patients with high-risk hepatoblastoma. Cancer Research UK and Cancer Research Switzerland/Oncosuisse.

Over the last 15 years, various oncology groups throughout the world have used the PRETEXT system for staging malignant primary liver tumours of childhood. This paper, written by members of the radiology and surgery committees of the International Childhood Liver Tumor Strategy Group (SIOPEL), presents various clarifications and revisions to the original PRETEXT system.