Maximal resection improves survival in MGMT methylated very elderly glioblastoma patients

Background: Glioblastoma is the most aggressive primary tumor of the central nervous system, with particularly poor prognosis in elderly patients. Individuals aged ≥ 75 years remain underrepresented in clinical trials, resulting in limited evidence to guide treatment decisions. This study aimed to analyze treatment patterns and survival outcomes in patients aged 75 years or older with newly diagnosed IDH-wildtype glioblastoma. Methods: We conducted a single-center retrospective study of 108 consecutive patients aged ≥ 75 years who underwent surgical intervention between 2016 and 2022. Patients were stratified by age group (75–79 vs. ≥80 years), surgical modality (biopsy vs. resection), extent of resection (maximal vs. submaximal), MGMT promoter methylation status, and adjuvant therapy. Overall survival (OS) and progression-free survival (PFS) were assessed using Kaplan–Meier analysis and Cox proportional hazards models. Results: The median age was 79 years, and 46.3% of patients were female. Biopsy alone was performed in 33.3% of patients, while 60.8% underwent surgical resection. Resection significantly improved OS compared with biopsy (p = 0.0047), with maximal resection providing superior OS compared with submaximal resection (p = 0.00016). The benefit of maximal resection was most pronounced in patients aged 75–79 years and in those with MGMT-methylated tumors. Among adjuvant treatments, radiochemotherapy conferred the strongest survival advantage (HR 0.174, 95% CI 0.086–0.355, p < 0.001). Conclusions: Maximal resection significantly improves survival in glioblastoma patients aged ≥ 75 years, particularly those with MGMT-methylated tumors, and should be considered even in selected patients aged ≥ 80 years. These findings underscore the importance of individualized treatment strategies and support the feasibility of aggressive surgical management in very elderly patients with favorable clinical status.