Clinical Analysis for Brain Tumor-Related Epilepsy during Chemotherapy for Systemic Cancer with Single Brain Metastasis

PURPOSE The purpose of this prospective observational study was to determine the incidence, patterns, and predisposing factors for brain tumor-related epilepsy (BTRE) during chemotherapy for systemic cancer with single brain metastasis (BM). MATERIALS AND METHODS Between February 2006 and June 2010, 103 patients who underwent chemotherapy for systemic cancer with single BM were enrolled. We compared the clinical factors of patients and BM between patients with and without BTRE. We determined the number of patients with BTRE attacks, and seizure-free survival according to the following comparative groups: presence vs. absence of a history of BTRE; high-risk vs. low-risk groups; and presence vs. absence of disease-progression of BM. RESULTS Ninety-three of 103 patients (90.3%) remained seizure-free during chemotherapy. The seizure-free rates were 88.9% and 91.0% among patients with or without a history of BTRE, respectively (p=0.694), 87.8% and 92.6% among high- and low-risk patients (p=0.427), respectively, and 62.5% and 98.7% among patients with or without disease-progression of BM (p=0.001), retrospectively. Based on multivariate analysis, the significance of abnormal findings on electroencephalogram (EEG) (p=0.017), and the absence of disease-progression of BM (p=0.001) had an association with seizure-free survival. CONCLUSION The significance of abnormal findings on EEG, and disease-progression of BM play important roles in the development of BTRE during chemotherapy for systemic cancer with BM.