A pragmatic adaptation of the RANO clinical risk score for IDH-Wildtype glioblastoma in the absence of MGMT promoter methylation testing.

Abstract

Background: The novel RANO risk score provides prognostic stratification for patients with IDH-wildtype glioblastoma(GBM) and includes age, Karnofsky Performance Scale(KPS), RANO resection class(RRC), and MGMT promoter methylation(MGMTm). However, MGMTm testing is unavailable in many countries. We aimed to explore the prognostic performance of a RANO-adapted clinical score excluding MGMTm.

Methods: We applied the same scoring system established by original RANO score, excluding MGMTm. Three risk classes were defined as numerical scores derived through tertiles. The primary endpoint was overall survival(OS), and the secondary exploratory endpoint was progression-free survival(PFS).

Results: One-hundred twenty patients were included. Three risk classes were identified:low-risk(0-1 points,n:47, 39.2%), intermediate-risk(2-3 points,n:27, 22.5%), and high-risk(≥4 points,n:46, 38.3%). The median OS was 35.5 months(95% CI:21.1-49.9) for the low-risk group, 16 months(95% CI:9.9-22.1) for the intermediate-risk group, and 5 months(95% CI:3.6-6.3) for the high-risk group(p < 0.001). Similarly, the median PFS was 16.3 months(95% CI:12.3-20.3) for the low-risk group, 9.9 months(95% CI:7.2-12.6) for the intermediate-risk group, and 4.1 months(95% CI:3.5-4.7) for the high-risk group(p < 0.001).

Conclusion: This simplified RANO-adapted score demonstrated promising prognostic stratification using basic clinical parameters. As a pragmatic adaptation study, external validation is required before clinical application, particularly in settings where MGMTm testing is unavailable.