Sinusoidal Obstruction Syndrome During Chemotherapy of Pediatric Cancers and its Successful Management With Defibrotide

Severe hepatic sinusoidal obstruction syndrome in a patient with Wilms tumor and hereditary spherocytosis

A 7-year-old girl with a history of splenectomy for hereditary spherocytosis (HS) was diagnosed with renal hematoma after a blunt abdominal trauma while receiving aspirin. Multiple erythrocyte transfusions and transarterial embolization were performed without success. Eventual nephrectomy revealed severely necrotic and perforated Stage III Wilms tumor (WT). Radiochemotherapy was administered, but by the eighth week, she developed severe hepatic sinusoidal obstruction syndrome (HSOS). Her ferritin level at the time was 3406 ng/ml. Defibrotide and aggressive supportive measures provided full recovery. The patient was given deferasirox for iron chelation therapy and finished her treatment without incident. To our knowledge, just one patient with HS and WT has been described in the literature. The role of iron excess in HSOS pathogenesis in non-transplant patients has not been addressed before either. Transfusional hyperferritinemia, in addition to chemotherapeutics and radiation, may have contributed to the development of severe HSOS in our patient.

Treatment of Sinusoidal Obstruction Syndrome With Defibrotide in Pediatric Cancer Patients Following Nontransplant-associated Chemotherapy: A Case Report and Review of the Literature

Sinusoidal obstruction syndrome (SOS), formerly veno-occlusive disease (VOD), in pediatric cancer patients often presents as a complication of hematopoietic stem cell transplantation, and less commonly secondary to nontransplant-associated chemotherapy. Therapy with defibrotide is well-described as standard care for transplant-associated SOS/VOD, but the treatment of nontransplant-associated SOS/VOD is less clear. We report a 3-year-old with relapsed Wilms tumor and recurrent SOS/VOD, with successful use of defibrotide during chemotherapy. A review of pediatric cancer patients with nontransplant-associated SOS/VOD treated with defibrotide revealed 83 patients, and 66 were in remission. This review supports early treatment with defibrotide in patients with nontransplant-associated SOS/VOD.

Genetic Predictors for Sinusoidal Obstruction Syndrome-A Systematic Review

Sinusoidal obstruction syndrome (SOS) is a potentially life-threatening complication after hematopoietic stem cell transplantation (HSCT) or antineoplastic treatment without HSCT. Genetic variants were investigated for their association with SOS, but the evidence is inconclusive. We performed a systematic literature review to identify genes, gene variants, and methods of association analyses of genetic markers with SOS. We identified 23 studies after HSCT and 4 studies after antineoplastic treatment without HSCT. One study (4%) performed whole-exome sequencing (WES) and replicated the analysis in an independent cohort, 26 used a candidate-gene approach. Three studies included >200 participants (11%), and six were of high quality (22%). Variants in 34 genes were tested in candidate gene studies after HSCT. Variants in GSTA1 were associated with SOS in three studies, MTHFR in two, and CPS1, CTH, CYP2B6, GSTM1, GSTP1, HFE, and HPSE in one study each. UGT2B10 and LNPK variants were identified in a WES analysis. After exposure to antineoplastic agents without HSCT, variants in six genes were tested and only GSTM1 was associated with SOS. There was a substantial heterogeneity of populations within and between studies. Future research should be based on sufficiently large homogenous samples, adjust for covariates, and replicate findings in independent cohorts.

Defibrotide for the treatment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome following nontransplant-associated chemotherapy: Final results from a post hoc analysis of data from an expanded-access program

BACKGROUND

Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially fatal complication of conditioning for hematopoietic stem cell transplantation (HSCT) but can occur after nontransplant-associated chemotherapy. Following HSCT, VOD/SOS with multi-organ dysfunction (MOD) may be associated with >80% mortality. Defibrotide is approved to treat severe hepatic VOD/SOS post-HSCT in patients aged >1 month in the European Union and hepatic VOD/SOS with renal or pulmonary dysfunction post-HSCT in the United States. Prior to US approval, defibrotide was available to treat VOD/SOS through an expanded-access treatment (T-IND) program. A post hoc analysis of nontransplant-associated VOD/SOS patients treated with defibrotide initiated within 30 days of starting chemotherapy and followed for 70 days is presented.

PROCEDURE

Patients were diagnosed by Baltimore or modified Seattle criteria or biopsy, and received defibrotide 25 mg/kg/day in four divided doses (≥21 days recommended).

RESULTS

Of the 1,154 patients in the T-IND, 137 had nontransplant-associated VOD/SOS, 82 of whom developed VOD/SOS within 30 days of starting chemotherapy. Of them, 66 (80.5%) were aged ≤16 years. Across all the 82 patients, Kaplan-Meier estimated day +70 survival was 74.1%, 65.8% in patients with MOD (n = 38), and 81.3% in patients without MOD (n = 44). By age group, Kaplan-Meier estimated day +70 survival was 80.1% in pediatric patients (n = 66) and 50.0% in adults (n = 16). Treatment-related adverse events occurred in 26.8%.

CONCLUSIONS

In this post hoc analysis of 82 patients initiating defibrotide within 30 days of starting chemotherapy, Kaplan-Meier estimated survival was 74.1% at 70 days after defibrotide initiation. Safety profile was consistent with prior defibrotide studies.

Venoocclusive disease due to chemotherapy for pediatric acute lymphoblastic leukemia is associated with increased levels of plasminogen-activator inhibitor-1

We describe three cases of sinusoidal obstruction syndrome/venoocclusive disease (SOS) in pediatric patients with acute lymphoblastic leukemia (ALL). All three episodes occurred during or just after the induction or reinduction phase of treatment based on prednisone/dexamethasone, vincristine, daunorubicin, and pegylated-l-asparaginase. SOS episodes were categorized as mild/moderate and resolved in 7, 10, and 16 days using supportive measures or defibrotide therapy. In all three episodes, the clinical diagnosis of SOS was associated with a significant increase in plasminogen-activator inhibitor-1 (PAI-1) that reduced with patient clinical improvement. PAI-1 warrants study as a diagnostic marker for SOS in ALL.