CTNI-47. TUMOR TREATING FIELDS COMBINE WITH TEMOZOLOMIDE FOR NEWLY DIAGNOSED GLIOBLASTOMA: A RETROSPECTIVE ANALYSIS OF CHINESE PATIENTS

Abstract

Abstract BACKGROUND TTFields plus Temozolomide (TTFields/TMZ) extended survival versus TMZ alone in newly diagnosed glioblastoma (GBM) patients in the EF-14 trial. We report a retrospective analysis of Chinese newly diagnosed GBM patients who received TTFields combine with TMZ treatment and traditional TMZ monotherapy from May 2019 to May 2021 in Shanghai Hua Shan hospital.METHOD: Overall survival (OS) and progression-free survival (PFS) curves were constructed using the Kaplan-Meier method. A Cox proportional hazards regression model with inverse probability of treatment weighting (IPTW) based on propensity score was used to assess the effect of TTFields and account for confounding factors. RESULT: In the preliminary analysis, the PFS in the TTFields/TMZ arm was 16 months (95% CI:9.6–24.6) versus 11 (95% CI: 9–12) with TMZ alone (p ＜0.05). Median overall survival was 21.8 months (95% CI 17.4-NA) with TTFields/TMZ versus 15 months (95% CI 13–18; HR 0.43, p ＜0.01) with TMZ alone. In the Multivariate analysis, Surgery type, STUPP scheme, IDH status, and TTFields use were identified as favorable prognostic factors. After PSM adjustment, the groups were similar, except that MGMT promoter methylation remained more in the TMZ group (12 v 32; P = 0.011). Upon IPTW Survival analysis, TTFields was associated with a significantly lower risk of death (hazard ratio [HR], 0.19 in OS (95% CI 0.09–0.41) and progression (HR, 0.35 (95% CI 0.14–0.91) compared with TMZ alone. CONCLUSION In the analysis of our single center of patients with glioblastoma, the addition of TTFields to maintenance temozolomide chemotherapy vs maintenance temozolomide alone, resulted in statistically significant improvement in progression-free survival and overall survival. These results are consistent with the outcome of EF-14.