Is sarcopenia a predictor of overall survival in primary IDH-wildtype GBM patients with and without MGMT promoter hypermethylation?

Background: In this study, we aimed to examine the success of temporal muscle thickness (TMT) and masseter muscle thickness (MMT) in predicting overall survival (OS) in primary IDH-wild glioblastoma (GBM) patients with and without MGMT promoter hypermethylation through publicly available datasets. Methods: We included 345 primary IDH-wild GBM patients with known MGMT promoter hypermethylation status who underwent gross-total resection and standard treatment, whose data were obtained from the open datasets. TMT was evaluated on axial thin section postcontrast T1-weighted images, and MMT was evaluated on axial T2-weighted images. The median TMT and MMT were used to determine the cut-off point. Results: The findings showed that median TMT 9.5 mm and median MMT 12.7 mm determined the cut-off value in predicting survival. Both TMT and MMT values less than the median muscle thickness were negatively associated with OS (TMT<9.5: HR 3.63 CI 2.34-4.23, p <0.001, MMT<12.7: HR 3.53 CI 2.27-4.07, p <0.001). When patients were classified according to MGMT positivity, the findings showed MGMT-negative patients (TMT<9.5: HR 2.54 CI 1.89-3.56, p <0.001, MMT<12.7: HR 2.65 CI 2.07-3.62, p <0.001) and MGMT-positive patients (TMT<9.5: HR 3.84 CI 2.48-4.28, p <0.001, MMT<12.7: HR 3.73 CI 2.98-4.71, p <0.001). Conclusion: Both TMT and MMT successfully predict survival in primary GBM patients. In addition, it can successfully predict survival in patients with and without MGMT promoter hypermethylation.