Veno-occlusive disease of the liver in children treated for Wilms tumor

Hepatotoxicity consistent with the clinical diagnosis of veno-occlusive disease (VOD) of the liver has been suspected after conventional anti-cancer chemotherapy in children. To establish the incidence of hepatotoxicity and its relationship with VOD, we analyzed toxicity data obtained on 511 children affected by Wilms tumor and treated according to the SIOP-9 protocol. They all received pre- and postnephrectomy chemotherapy using dactinomycin (AD) and vincristine (VCR) +/- other drugs +/- radiotherapy according to surgical stage and histology. Sixty-four patients suffered at least one episode of hepatotoxicity and 41 satisfied the criteria for a clinical diagnosis of VOD. In this latter group, toxicity occurred during preoperative treatment in 15 patients and was confirmed histopathologically in 9 of the 16 liver biopsies obtained. There was a higher percentage of children aged less than 1 year at diagnosis in the VOD group than in the other patients (24% vs. 11.4%). The degree of liver damage in the younger patients seems important, as suggested by a higher increase in transaminases. VOD developed in 12% of the 68 irradiated children vs. 7% in the non-irradiated group. Statistical analysis showed an increased risk of VOD in younger patients (p < 0.001) and in those receiving radiotherapy (p < 0.001). All patients recovered after 6-180 days using supportive therapy only. (1) 8% of children treated according to the SIOP-9 protocol, developed hepatotoxicity consistent with VOD. Excluding patients who received radiotherapy, the incidence was 6%. These figures are much higher than in earlier reports, though different diagnostic criteria were used. (2) Chemotherapy with AD and VCR seems to be a major cause of VOD. (3) Risk factors are young age and concomitant radiotherapy. (4) VOD does not prejudice positive outcome for these patient

Development of a physiologically based pharmacokinetic model of actinomycin D in children with cancer

AIMS: Use of the anti‐tumour antibiotic actinomycin D is associated with development of hepatotoxicity, particularly in young children. A paucity of actinomycin D pharmacokinetic data make it challenging to develop a sound rationale for defining dosing regimens in younger patients. The study aim was to develop a physiologically based pharmacokinetic (PBPK) model using a combination of data from the literature and generated from experimental analyses. METHODS: Assays to determine actinomycin D Log P, blood:plasma partition ratio and ABCB1 kinetics were conducted. These data were combined with physiochemical properties sourced from the literature to generate a compound file for use within the modelling‐simulation software Simcyp (version 14 release 1). For simulation, information was taken from two datasets, one from 117 patients under the age of 21 and one from 20 patients aged 16–48. RESULTS: The final model incorporated clinical renal and biliary clearance data and an additional systemic clearance value. The mean AUC(0‐26h) of simulated subjects was within 1.25‐fold of the observed AUC(0‐26h) (84 ng h ml(−1) simulated vs. 93 ng h ml(−1) observed). For the younger age ranges, AUC predictions were within two‐fold of observed values, with simulated data from six of the eight age/dose ranges falling within 15% of observed data. Simulated values for actinomycin D AUC(0‐26h) and clearance in infants aged 0–12 months ranged from 104 to 115 ng h ml(−1) and 3.5–3.8 l h(−1), respectively. CONCLUSIONS: The model has potential utility for prediction of actinomycin D exposure in younger patients and may help guide future dosing. However, additional independent data from neonates and infants is needed for further validation. Physiological differences between paediatric cancer patients and healthy children also need to be further characterized and incorporated into PBPK models

Glomerular filtration rate and prevalence of chronic kidney disease in Wilms’ tumour survivors

Glomerular filtration rate (GFR) was evaluated in 32 Wilms’ tumour survivors (WTs) in a cross-sectional study using 99 Tc-diethylene triamine pentaacetic acid (99 Tc-DTPA) clearance, the Schwartz formula, the new Schwartz equation for chronic kidney disease (CKD), cystatin C serum concentration and the Filler formula. Kidney damage was established by beta-2-microglobulin (B-2-M) and albumin urine excretion, urine sediment and ultrasound examination. Blood pressure was measured. No differences were found between the mean GFR in 99 Tc-DTPA and the new Schwartz equation for CKD (91.8 ± 11.3 vs. 94.3 ± 10.2 ml/min/1.73 m2 [p = 0.55] respectively). No differences were observed between estimated glomerular filtration rate (eGFR) using the Schwartz formula and the Filler formula either (122.3 ± 19.9 vs. 129.8 ± 23.9 ml/min/1.73 m2 [p = 0.28] respectively). Increased urine albumin and B-2-M excretion, which are signs of kidney damage, were found in 7 (22%) and 3 (9.4%) WTs respectively. Ultrasound signs of kidney damage were found in 14 patients (43%). Five patients (15.6%) had more than one sign of kidney damage. Eighteen individuals (56.25%) had CKD stage I (10 with signs of kidney damage; 8 without). Fourteen individuals (43.75%) had CKD stage II (6 with signs of kidney damage; 8 without). The new Schwartz equation for CKD better estimated GFR in comparison to the Schwartz formula and the Filler formula. Furthermore, the WT survivors had signs of kidney damage despite the fact that GFR was not decreased below 90 ml/min/1.73 m2 with 99 Tc- DTPA

Rationale for the treatment of children with CCSK in the UMBRELLA SIOP-RTSG 2016 protocol

The International Society of Paediatric Oncology-Renal Tumour Study Group (SIOP-RTSG) has developed a new protocol for the diagnosis, treatment, and follow-up monitoring of childhood renal tumours-the UMBRELLA SIOP-RTSG 2016 protocol (the UMBRELLA protocol). This protocol has been designed to continue international collaboration in the treatment of childhood renal tumours and will be implemented in over 50 different countries. Clear cell sarcoma of the kidney, which is a rare paediatric renal tumour that most commonly occurs in childre