QOL-22. Prognostic Associations of the G8 Geriatric Screening Tool in the EORTC Brain Tumor Group Trials 1608 and 1709 in Newly Diagnosed Glioblastoma

The G8 screening assessment tool has been validated to assess frailty risk in older patients with cancer. A score of 14 or less is considered to identify patients at risk of frailty. The G8 has been implemented for all EORTC clinical trials including patients 70 years or older since 2017. Here we assessed the prognostic value of the G8 at baseline in older patients with newly diagnosed glioblastoma enrolled in clinical trials. Data from 83 patients aged 70 or older enrolled in the 1608 STEAM trial (NCT 03224104) (n=20) or the 1709 MIRAGE trial (NCT 03345095) (n=63) were analyzed. We defined a G8 low (≤14) and a G8 high group (15-17). The median age was 73 years, 29 patients (34.9 %) were female, 54 patients (65.1 %) were male. The KPS was 90 or more in 42 patients (50.6 %). Steroids were taken at baseline by 33 patients (39.8 %). 38 patients (45.8 %) were assigned to the G8 low group, and 45 patients (54.2 %) to the G8 high group. Patients with a KPS of 90 or 100 were more often in the G8 high group (adjusted OR = 6.98, 95% CI 2.19 – 25.64). Patients in the G8 high group had higher means for global health status scale and functioning scores at baseline than patients in the G8 low group. Treatment delivery measured by the relative dose intensity was better in patients with a high G8 than in patients with a low G8 (OR = 2.26, 95% CI 0.81- 6.53). Patients in the G8 low group tended to experience more toxicity than patients in the G8 high group. Patients in the G8 high group had a longer progression-free (adjusted HR = 0.37, 95% CI 0.20 – 0.68, p=0.0013) and overall survival (adjusted HR = 0.40, 95% CI 0.21 – 0.75, p=0.0045). The G8 score may be a powerful tool for prognostic assessment and for patient stratification in old patients with glioblastoma.