Male gender is associated with seizure risk in low-grade glioma (LGG) patients.

Abstract

e13520 Background: Up to 90% of LGG patients present with seizures, but the risk of developing seizure is not known. Our goal was to determine the association between clinical and molecular factors with seizure incidence in LGG patients. Methods: Retrospective study from 2/2002-1/2015 involving 291 patients ≥18 years old, with diagnosis of WHO grade II glioma. Intractable seizure was defined as patients needing ≥2 anti-epileptic drugs. Chi-square tests of association were used to test for associations between factors and outcome measures. Results: Study population was 54% men, median age of 51, with oligodendroglioma (47%), oligoastrocytoma (25%), astrocytoma (21%), NOS (7%). Among patients with molecular testing (87%), 32% had IDH mutation (IDHmt) and 1p/19q co-deletion, 37% IDHmt and 1p/19q intact and 18% IDH wildtype LGG. Sixty-eight percent of patients had seizures prior to LGG diagnosis; 41% intractable seizures. A trend toward higher incidence of pre-operative seizure was observed in IDHmt LGG patients (p = 0.09). On univariate analysis (Table), oligodendroglioma was significantly associated with a higher risk of intractable seizures. Male gender was strongly associated with the risk of seizure at presentation, seizure development after surgery, and intractable seizures. Conclusions: Consistent with historical data, the majority of our patients presented with seizure; oligodendroglioma with higher risk of intractable seizures. Unexpectedly, gross resection did not favorably predict seizure outcome, possibly due to our small study population. Our study only showed a trend towards higher seizure occurrence in IDHmt LGG patients. Our finding of association between male gender and seizure risk in LGG patients mirrors that of Pallud et al (Brain 2014) and warrants further investigation into the possible molecular basis of sex differences in epileptogenesis in LGG.[Table: see text]