PB0266 - Cerebral Venous Sinus Thrombosis in Pediatric Acute Lymphoblastic Leukemia: Risk Factors and Long-Term Outcomes

Background: Cerebral venous sinus thrombosis (CVST) has been identified as a complication in 1-2% of patients treated for pediatric acute lymphoblastic leukemia (ALL), with subsequent risk of neurological morbidity and mortality rate of 8-13%. Multiple risk factors have been identified in acquisition of CVST, including active malignancy, inherited thrombophilia, infection, or pharmacologic side effects.

Aims: To describe the incidence, risk factors, and long-term outcomes of CVST in children with ALL at a tertiary pediatric hospital.

Methods: A retrospective cohort study comprised of pediatric patients (ages 1-18 years) with newly diagnosed or first-relapse ALL enrolled on Children’s Oncology Group and four Pediatric Oncology Group protocols from 2002 to 2021. Included were patients diagnosed with CVST and had confirmed computed tomography/venography or magnetic resonance imaging/venography. Patients were excluded if they developed extracerebral or isolated jugular vein thrombosis. Long-term neurologic status was evaluated based on clinic notes from most recent follow up neurologic exam. Baylor College of Medicine institutional review board approval was obtained for the study.

Results: Nineteen cases of CVST have been identified in pediatric ALL patients at our center, an incidence of 8.8% of patients with CVST (N=215). In regards to etiology of CVST, 68% (N=13) of cases occurred during induction, followed by consolidation (16%, N=3) and maintenance therapy (16%, N=3). Presenting symptoms, therapeutic intervention and neurologic outcomes varied across the cohort (See Table 1), from normal neurologic exams at five years post diagnosis of CVST, to patients with persisting neurologic deficits including decreased strength, cranial nerve palsy, and seizure disorders.

Conclusion(s): CSVT is a notable complication of pediatric ALL therapy. In our cohort, significant risk factors identified for CSVT included immunophenotype, age and side effects of chemotherapy. However, due to the rarity and variability of cases, there is no universally accepted consensus on identified high-risk variables that warrant implementation of preventative thromboprophylaxis.