Prognostic Impact of Surgical Resection at Initial Recurrence in IDH-Mutant Lower-Grade Gliomas

Overview

This retrospective study evaluated the impact of surgical resection at first recurrence on progression-free and overall survival in patients with IDH-mutant lower-grade gliomas. The analysis included volumetric assessment of residual tumor and demonstrated that gross total resection at recurrence is associated with improved outcomes compared to non-surgical treatments.

Background

Lower-grade gliomas with IDH mutations, including diffuse astrocytoma and oligodendroglioma, generally have favorable prognoses. Initial maximal safe resection is a key treatment strategy, but the role of surgery at tumor recurrence remains unclear. Previous studies lacked comprehensive molecular characterization and volumetric tumor assessment, limiting conclusions about survival benefits of repeat resection. This study addresses these gaps by analyzing a molecularly defined cohort with quantitative imaging data.

Data Highlights

Key Findings

• Gross total resection (GTR) at first recurrence was defined by no residual tumor volume on volumetric MRI analysis.
• Repeat surgical resection was performed in approximately one-third of patients at first recurrence.
• Patients undergoing GTR at recurrence showed improved progression-free survival after recurrence (PFS-2) and survival after recurrence (SAR) compared to those receiving non-surgical treatments.
• Neurological function prior to treatment was generally preserved, with high median KPS and majority neurologically intact.
• Exclusion of astrocytoma patients with CDKN2A/B homozygous deletion ensured focus on patients with better prognostic profiles.

Clinical Implications

Repeat surgical resection, especially achieving gross total resection, should be considered in selected patients with recurrent IDH-mutant lower-grade gliomas to potentially improve survival outcomes. Volumetric assessment of residual tumor is valuable for evaluating extent of resection and guiding postoperative management. Multidisciplinary evaluation remains critical to tailor treatment strategies based on tumor subtype, patient condition, and prior therapies.

Conclusion

This study supports the prognostic benefit of gross total resection at first recurrence in IDH-mutant lower-grade gliomas, highlighting the importance of surgical intervention and precise volumetric evaluation in managing recurrent disease.

References

1. WHO CNS 5 Classification (2021) -- WHO Classification of Tumors of the Central Nervous System
2. AANS/CNS Joint Tumor Section Guidelines (2022) -- Surgery for Recurrent Glioma WHO Grade 2
3. Previous Retrospective Studies (2010-2020) -- Impact of Repeat Resection on Glioma Outcomes