Choice of antiepileptic drugs affects the outcome in cancer patients with seizures.

BACKGROUND: Seizures in cancer patients may occur as a result of CNS primary or metastatic tumor, brain surgery, vascular disease, pharmacologic treatment (including chemotherapy), radiation therapy, or metabolic disorders. The aims of the study were to a) determine whether seizures in cancer patients have prognostic implications and b) study patient outcome based on the antiepileptic drug used.

METHOD: This is a prospective comparative study that included adult cancer patients with and without seizures from May 2010 to November 2016 seen by the neuro-oncology unit at a cancer referral center. Variables included age, gender, oncologic characteristics, seizure features, treatment, and outcome. Parametric and non-parametric tests were used to compare groups, and Kaplan-Meier curves with the log-rank test were used to analyze survival. Cox multivariate regression tests were used to describe survival and compare groups.

RESULTS: A total of 823 patients were included; 419 (51%) patients had at least one seizure and were compared with 404 (49%) who did not experience seizures. Of the seizure group, 53% had brain metastases, 36% did not have a brain tumor, and 11% had a primary brain tumor. No survival differences were noted among patients with brain metastases or primary tumor with or without seizures. In the seizure group, 249 (59%) required only one antiepileptic drug, whereas 134 (32%) required 2 or more. A better overall survival was identified for patients prescribed carbamazepine (p = 0.02), lamotrigine (p = 0.015), levetiracetam (p = 0.03), and valproic acid (p = 0.009).

CONCLUSIONS: Patients with primary or metastatic brain tumors have the same overall survival with or without seizures. However, patients with seizures not treated with antiepileptics exhibit worse overall survival.