Prophylactic Anti-Seizure Medication Use in Newly Diagnosed Brain Tumor Patients
Se Ryeong Jang1, Katherine Peters2, Stella Ngo1, Marcia Morita-Sherman1
1Eisai Inc., 2Duke University Medical Center
Objective:
To evaluate the use of prophylactic anti-seizure medications (ASM) in seizure-naïve patients with newly diagnosed brain tumors
Background:
Many physicians continue to prescribe ASM to seizure-naïve brain tumor patients, even though treatment guidelines recommend against such practice.
Design/Methods:
In this retrospective observational study, electronic medical records from the TriNetX Dataworks – USA Network were used to identify patients with a record of brain tumor diagnosis and no evidence of seizure diagnosis from 2012 to 2017. Patients who were prescribed a prophylactic ASM were propensity-score (PS) matched with those who were not at a 1:1 ratio on age, sex, race, ethnicity, tumor types, comorbidities, prescription medications, and procedures. Prophylactic ASM use was defined as the prescription of  ≥1 ASM from 30 days before the first brain tumor diagnosis and up to 30 days afterwards. Hazard ratios for seizure development and mortality were assessed using Cox proportional hazards regression models. The first brain tumor diagnosis date was considered the index date, and patients were followed up to 5 years from their first prescription record, death, or whichever occurred first. 
Results:
Of the 117,834 seizure-naïve patients who were newly diagnosed with brain tumor, 18,963 (16.1%) were prescribed a prophylactic ASM. Of the 14,238 patients in each PS-matched cohort, 778 of those on prophylaxis (5.5%) and 452 of those not on prophylaxis (3.0%) developed a seizure during the follow-up period (Hazard Ratio: 2.3 [95% CI: 2.0, 2.6]). Mortality hazard was 1.1 times (95% CI: 1.1, 1.2) higher in those on prophylactic ASM.
Conclusions:
Seizure-naïve patients with brain tumor who were prescribed a prophylactic ASM had a higher hazard of developing a seizure compared with those who were not. Unobserved risk factors that were not controlled for may explain the apparent analysis results. Clinical trials are warranted to further examine this controversial disease management approach.
10.1212/WNL.0000000000203769