2145 - Prognostic Factors for Progression-Free Survival after Resection and after Recurrence in IDH-Mutant Glioma
Presenter(s)
Y. T. Liu1,2, K. Chang3,4, W. Y. Chen5,6, C. W. Wang5, and H. K. T. Liang1,6; 1Department of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 2Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital Yunlin Branch, Yunlin, Taiwan, 3Department and Graduate Institute of Forensic Medicine, National Taiwan University School of Medicine, Taipei, Taiwan, 4Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan, 5Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan, 6Department of Radiation Oncology, National Taiwan University Cancer Center, National Taiwan University Hospital, Taipei, Taiwan
Purpose/Objective(s): Outcomes in isocitrate dehydrogenase (IDH)–mutant gliomas are generally favorable but variable. We hypothesized that perioperative magnetic resonance imaging (MRI) features and extent of resection are associated with progression-free survival after surgery (PFS1), and that postrecurrence pathologic features and salvage treatment are associated with progression-free survival after first recurrence (PFS2).
Materials/Methods: We retrospectively reviewed 37 patients with IDH-mutant gliomas who underwent tumor resection at a single institution between June 2006 and June 2023. Pre- and postoperative MRI were evaluated for tumor location, corpus callosum (CC) invasion, and the ratio of maximum peritumoral edema extent to maximum tumor diameter (edema-to-tumor ratio), among other features. Extent of resection was categorized as gross total vs subtotal. Adjuvant radiotherapy (intensity-modulated or volumetric modulated arc therapy) and systemic agents were administered at the treating physician's discretion. PFS1, PFS2, and overall survival (OS) were calculated.
Results: Most tumors were frontal (27/37 [73%]), and 18/37 (49%) demonstrated CC invasion. Median PFS1 was 38.5 months (95% CI, 22.6–56.8). Higher edema-to-tumor ratio, CC invasion, and subtotal resection were associated with shorter PFS1 on multivariate analysis. Median PFS2 was 12.1 months (95% CI, 9.3–not reached). Histologic progression at first recurrence or initial World Health Organization grade 4 disease, and omission of salvage radiotherapy , were associated with shorter PFS2 on multivariate analysis. Shorter PFS2 was associated with shorter OS.
Conclusion: In IDH-mutant glioma, perioperative MRI markers (edema-to-tumor ratio and CC invasion) and extent of resection may improve postoperative prognostic stratification. After recurrence, pathologic aggressiveness and use of salvage radiotherapy were associated with PFS2. These variables may support risk-adapted surveillance and salvage planning and warrant validation in larger cohorts.
| Table. Prognostic Factors Associated with Adverse Progression-Free Survival After the First Recurrence. | Univariate analysis | Multivariate analysis | ||||
| Prognostic factors | n (%) | HR (95% CI) | P value | HR (95% CI) | P value | |
| Corpus callosum invasion | No | 16 (62) | 1 | 1 | ||
| Yes | 10 (38) | 1.09 (1.07 to 8.31) | 0.04 | 0.55 (0.11 to 2.83) | 0.47 | |
| Pathological progression | No | 8 (31) | 1 | 1 | ||
| Yes | 18 (69) | 8.88 (1.17 to 67.48) | 0.04 | 15.33 (1.33 to 176.21) | 0.03 | |
| Salvage craniotomy | Yes | 15 (58) | 1 | |||
| No | 11 (42) | 1.04 (0.38 to 2.88) | 0.94 | |||
| Salvage radiotherapy | Yes | 14 (54) | 1 | 1 | ||
| No | 12 (46) | 3.75 (1.34 to 10.46) | 0.01 | 7.03 (1.18 to 42.06) | 0.03 | |