Single‑center retrospective study of factors associated with early discontinuation of tumor‑treating fields therapy in glioblastoma

Glioblastoma (GBM) is the most aggressive primary malignant tumor of the adult central nervous system with poor survival outcomes despite multimodal standard treatment. Tumor-treating fields (TTFields) therapy prolongs survival in patients with newly diagnosed GBM; however, sustained adherence is essential to achieve therapeutic benefits. The risk factors for early discontinuation of TTFields remain poorly understood, as patients with treatment durations of <2-3 months have been typically excluded from previous analyses. In the present single-center retrospective study, the clinical and molecular factors associated with early discontinuation of TTFields were investigated in 16 consecutive adult patients with supratentorial GBM treated between September 2019 and February 2025. Early discontinuation was defined as the cessation of treatment within 90 days without resumption. Clinical variables, activities of daily living, neurocognitive assessments and molecular profiles were evaluated. Early discontinuation occurred in five patients (31.3%). Comparative analysis revealed that hemiparesis at treatment initiation (P=0.018), attentional impairment (P=0.036), lower baseline Karnofsky performance status (P=0.005) and Barthel Index (P=0.013) were significantly more frequent in the early discontinuation group than in the continuation group. Furthermore, overall survival was significantly shorter in the early discontinuation group (hazard ratio 8.857, 95% confidence interval 1.56-50.29, P=0.004), and progression-free survival showed a non-significant trend toward a shorter duration. No significant differences were found in the other neurocognitive test scores or molecular alterations. These findings indicated that specific neurological deficits and functional impairments may hinder treatment persistence. Therefore, early identification of at-risk patients and implementation of supportive strategies, including enhanced caregiver involvement and welfare support, may improve adherence and optimize the clinical benefits of TTFields in GBM.