Brain tumor-related epilepsy and risk factors for metastatic brain tumors: analysis of 601 consecutive cases providing real-world data.

OBJECTIVE: It is necessary to accurately characterize the epidemiology and trends of brain tumor-related epilepsy (BTE) in patients with metastatic brain tumors. This study aimed to determine the incidence of BTE associated with metastatic brain tumors and retrospectively investigate the risk factors for BTE. METHODS: This retrospective analysis included 601 of 631 consecutive patients with metastatic brain tumors who received treatment, including surgery, radiotherapy, and/or other treatments. BTE and the clinical course were examined retrospectively. Logistic regression multivariate analyses were performed to identify risk factors for BTE. RESULTS: BTE was reported in 148 (24.6%) of 601 patients during the entire course. Of these 148 patients, 81 (54.7%) had first-onset epilepsy (13.5% of all patients). Of the 520 cases of nonepileptic onset, 53 were in the prophylactic antiepileptic drug (AED) group. However, 12 of these patients and 55 of the no-prophylactic AED group developed epilepsy during the course of the study. Including these 67 patients, 148 patients were examined as the group of all epilepsy cases during the entire course. In 3 patients, the seizure progressed to status epilepticus. In most patients, the BTE (n = 83, 56.1%) manifested as focal aware seizures. Logistic regression analysis identified young age (p = 0.037), male sex (p = 0.026), breast cancer (p = 0.001), eloquent area (p < 0.001), peritumoral edema (p < 0.001), dissemination (p = 0.013), and maximum tumor volume (p = 0.021) as significant risk factors for BTE. BTE was more common with tumor volumes greater than the cutoff value of 1.92 ml. CONCLUSIONS: BTE appears to be more likely to occur in cases with young age, male sex, breast cancer, tumors involving eloquent areas, brain edema, dissemination, and giant tumors.