The effect of anticonvulsants on survival among patients with GBM brain tumors undergoing radiation: A SEER-Medicare analysis.

BACKGROUND: Patients with glioblastoma multiforme (GBM) who undergo radiation often require anticonvulsants during treatment. The aim of this study was to determine the effects of anticonvulsants on GBM clinical outcomes. METHODS: A retrospective analysis was performed using the SEER-Medicare database. All patients with GBM who were treated with radiation and concurrently taking an anticonvulsant were included in final analysis. Each class of medication was further subdivided by mechanism of action. Descriptive statistics were performed for all variables. Kaplan Meier survival curves were generated for each class of medication and Cox regression analysis was performed to assess the effect of each individual variable on survival. RESULTS: There were 1561 patients available for final analysis. On multivariate Cox regression analysis, GBM patients taking sodium/calcium (Na/Ca) channel blocker anticonvulsants during radiation therapy demonstrated both improved overall survival (OS) (HR, 0.799; 95% CI [0.716, 0.891]; P < 0.001) and cancer specific survival (CSS) (HR, 0.814; 95% CI [0.727, 0.911]; P < 0.001). CONCLUSION: OS was significantly better in patients taking NA/Ca channel blockers among patients with GBM who were concurrently undergoing radiation therapy.

Brachytherapy vs external beam therapy among NSCLC patients undergoing limited surgical resection.

PURPOSE: To compare brachytherapy to external beam radiation therapy (EBRT) with respect to overall survival (OS) and disease-specific survival (DSS) among NSCLC patients undergoing limited surgical resection. METHODS: All cases of T1-4 N0 M0 NSCLC undergoing limited resection and either brachytherapy or EBRT diagnosed between 2004 and 2014 were extracted from the Surveillance, Epidemiology, and End Results database. Chi-square test and Fisher's exact analysis were used to analyze categorical variables while Student's t-test was used to analyze continuous variables. Univariate analysis to assess for differences in survival with respect to covariates was performed with the log-rank test. Multivariable analysis was performed with Cox proportional hazards regression models among the entire cohort and after sub-stratification by T stage. RESULTS: Among 543 patients, 471 underwent EBRT and 72 underwent brachytherapy. Brachytherapy demonstrated improved OS and DSS on univariate analysis as compared to EBRT (p < 0.05). Cox regression also demonstrated improved OS and DSS with brachytherapy (HR 0.604; 95% CI [0.380; 0.961] and HR 0.524; 95% CI [0.303; 0.908], respectively). Sub-cohort analysis demonstrated significant improvement in survival only among patients with T1 disease with similar survival between brachytherapy and EBRT among higher stage disease. CONCLUSIONS: Patients undergoing brachytherapy for T1-T4, N0, M0 NSCLC demonstrated at least similar survival as compared to those undergoing EBRT among patients undergoing limited resection. Improved survival was demonstrated among patients with T1 disease.