QOL-01. A Propensity-Score Matched Prospective Study on the Impact of TTFields on Overall Survival and Quality of Life in Newly Diagnosed WHO Grade 4 Astrocytoma Patients

BACKGROUND Tumour treating fields (TTF) has been shown to improve overall survival (OS) for patients with WHO grade 4 astrocytoma, but few explored quality-of-life (QoL) in these patients. METHODS This was a prospective multi-center study of adult patients diagnosed with WHO grade 4 astrocytoma from 2018 to 2023, who received TTF for >1 month after completing standard therapy. A propensity-score matched comparison, 1:2 ratio with historical control patients was performed. Patients also completed EORTC QLQ-30/BN20 questionnaires before TTF and at 3-month intervals. The primary endpoint was OS and secondary endpoints included QoL at 3 months. RESULTS 141 patients were reviewed, comprising of 47 TTF patients (33%) and 94 propensity-score matched controls. Mean duration of TTF use was 10±8 months (range 1-28). The mean age of the TTF group was 54±13 years, and for the control group 52±13 years. 60% (n=28) were male, similar to the control group with 71% (n=67) (p-value 0.16). 72% of TTF patients had a preoperative KPS score ≥80, while control patients had 70% (p-value 0.79). 20 (43%) TTF patients and 42 (45%) controls were pMGMT methylated (p-value 0.81). 21 (45%) of TTF patients and 55 (59%) of controls had gross total resection (p-value 0.72). The mOS of the TTF group was 22.4 months (IQR: 18.6-26.5), significantly longer than the control group (17.2 months; IQR: 12.1-22.3) (log-rank test: p-value 0.01). There was no significant change in overall EORTC scores for the TTF group from 0 to 9 months. There was no difference for EORTC functional and symptom scores between the TTF and control group (p=0.45, ANOVA) at 3 months. CONCLUSION TTF for newly-diagnosed WHO Grade 4 astrocytoma patients is an independent predictor for OS. QoL for TTF and control patients were similar. QoL over time for TTF patients did not deteriorate.