Sinusoidal obstruction syndrome/veno-occlusive disease after high-dose intravenous busulfan/melphalan conditioning therapy in high-risk Ewing Sarcoma

Drug-induced hepatic sinusoidal obstruction syndrome: current advances and future perspectives

Hepatic sinusoidal obstruction syndrome (HSOS) has gained recognition as a rare form of drug-induced liver injury (DILI) in recent years. Although extensively studied in the context of hematopoietic stem cell transplantation (HSCT), the applicability of this knowledge to drug-induced HSOS remains limited due to distinct etiological factors. The primary causes of drug-induced HSOS include the ingestion of pyrrolizidine alkaloid (PA)-containing plants, as well as the use of chemotherapeutic agents and immunosuppressive drugs. The underlying pathogenesis is not yet fully understood. Noninvasive diagnostic imaging modalities such as ultrasonography, computed tomography, and magnetic resonance imaging play a valuable role in diagnosis. Further research is essential to develop standardized severity grading systems and optimize treatment strategies. This review summarizes the key etiologies, pathological mechanisms, clinical features, diagnostic approaches, severity assessment, and therapeutic options for drug-induced HSOS.

Clinical features and risk factors of hepatic sinusoidal obstruction syndrome in children after hematopoietic stem cell transplantation: A single-center experience

Hepatic sinusoidal obstruction syndrome (SOS) is an illness with serious life effects that develops after hematopoietic stem cell transplantation (HSCT). We investigated the risk factors and clinical features of hepatic SOS in children following HSCT in 210 children who underwent allogeneic or autologous HSCT between 2009 and 2021 were analyzed in the context of SOS. The syndrome developed in 22 (10.4%) patients:frequently in neuroblastoma [24% (5/21)], hemophagocytic lymphohistiocytosis [57% (4/7)], and thalassemia major [22% (7/31)]. The median time from HSCT to diagnosis was 16 (6-38) days. Severe disease occurred in 8 (36%) patients, and mild/moderate in 14 (64%) and 4 patients died (18%). In univariate analyses, patient's age ≤ 2 years [odds ratio (OR)= 3.043, P = 0.028], pretransplant AST and ALT levels > 100 U/L (OR=3.576, P = 0.045), and chemotherapy/radiotherapy to abdomen before transplantation (OR = 3.162, P = 0.044) were determined as risk factors. In multivariate analysis, pre-transplant AST and ALT levels > 100 U/L (OR = 16.04, P = 0.010) and ferritin levels over 1000 mg/dl (OR=5.15, P = 0.047) were significant. The only independent risk factor on mortality was the age ≤ 2 years (P = 0.001). Although our study confirmed several risk factors for SOS, we failed to achieve some well-known risk factors. Precautions should be taken considering the factors affecting liver function before transplantation and the risk of SOS in infants receiving chemotherapy and radiotherapy before transplantation, such as neuroblastoma in which comparable results in respect to the chemotherapy only. The risk factors should be fully elucidated in multicenter studies to improve preventive and therapeutic strategies.

Primary Budd-Chiari syndrome versus sinusoidal obstruction syndrome: a review

Budd-Chiari syndrome (BCS) and sinusoidal obstruction syndrome (SOS) are two major vascular disorders of the liver, of which both can cause portal hypertension related complications, but their locations of obstruction are different. BCS refers to the obstruction from the hepatic vein to the junction between the inferior vena cava and right atrium, which is the major etiology of post-sinusoidal portal hypertension; by comparison, SOS is characterized as the obstruction at the level of hepatic sinusoids and terminal venulae, which is a cause of sinusoidal portal hypertension. Both of them can cause hepatic congestion with life-threatening complications, especially acute liver failure and chronic portal hypertension, and share some similar features in terms of imaging and clinical presentations, but they have heterogeneous risk factors, management strategy, and prognosis. Herein, this paper reviews the current evidence and then summarizes the difference between primary BCS and SOS in terms of risk factors, clinical features, diagnosis, and treatment.

Sinusoidal Obstruction Syndrome of the Liver Associated With 6-Mercaptopurine During Maintenance in a Child With T-cell Acute Lymphoblastic Leukemia

Sinusoidal obstruction syndrome (SOS) of the liver is a complication of chemotherapy most often encountered with hematopoietic stem cell transplant due to high-dose conditioning regimens, but it can also occur with regimens outside of the transplant setting. Mild-to-moderate SOS is a well-described 6-thioguanine toxicity; however, it has rarely been reported as secondary to 6-mercaptopurine, a related thiopurine. This report details a case of a 10-year-old male with T-cell acute lymphoblastic leukemia who developed severe SOS during maintenance therapy with 6-mercaptopurine, and a review of the related literature.

Histological response to neoadjuvant chemotherapy in localized Ewing sarcoma of the bone: A retrospective analysis of available scoring tools

AIM

The aim is to evaluate which of the existing scoring systems of histological response to neoadjuvant chemotherapy best stratifies the clinical outcome of patients with localized Ewing sarcoma of bone.

METHODS

474 patients with diagnosis of localized Ewing sarcoma of bone were included. The median follow-up was 13.5 years.

RESULTS

The overall survival and the disease-free survival (DFS) were 70.8% and 63.9% at 5 years. The percentage of histological response to neoadjuvant chemotherapy ranged between 5% and 100% (mean 83%). The agreement between Bologna System and the different percentual cut-offs of histological response to neoadjuvant chemotherapy was high, with kappa statistics of 0.83 for a cut-off of ≥90%; 0.86 for a cut-off of ≥95%; 0.79 for a cut-off of ≥96% and 0.61 for a cut-off of 100%. Statistically higher DFS rates for good responders compared to poor responders were found when using each given system. Model performance indicators showed that Bologna system had a lower AIC score and a higher c-statistics to predict DFS. When the patients classified as good responders using the different percentual cut-offs of histological response to neoadjuvant chemotherapy, were instead re-classified using the Bologna system, statistical differences were noted in DFS within each specific group.

CONCLUSIONS

All scoring tools to evaluate histological response to neoadjuvant chemotherapy offer good predictive value for DFS in localized Ewing's sarcoma of bone. The Bologna system better stratifies those patients with histological response to neoadjuvant chemotherapy between 90 and 99%, representing a more reliable scoring tool in this subset.

Pharmacotherapy in Children and Adolescents: Oncology

Pharmacotherapy in paediatric oncology is a difficult task. It is challenging to determine the optimal dose in children of different age groups. In addition, anticancer drugs display severe side effects reducing the quality of life. Late effects like secondary tumours and cardiotoxicity can be apparent years after treatment and must be taken into account when planning treatment schedules. Classical cytoreducing agents are still of great importance in treating children with leukaemia and solid tumours. In addition, drugs developed by rational drug design (targeted drugs) are a very important part of many treatment protocols, and newer drugs are emerging in several types of cancer. Unfortunately, there is only limited experience with newer drugs in children, because new drugs are mostly developed for adults. Complicated therapy regimens require a solid knowledge of the pharmacology of the drugs applied. This chapter attempts to introduce some pharmacological knowledge for the most important anticancer drugs in children with a focus on side effects and age-specific considerations.