Impact of Resection on Survival of Isocitrate Dehydrogenase 1-Mutated World Health Organization Grade II Astrocytoma After Malignant Progression

Objective To evaluate the impact of surgical resection and adjuvant treatment on the course of patients after malignant progression of previously treated isocitrate dehydrogenase 1 (IDH1)–mutated World Health Organization (WHO) grade II astrocytoma. Methods This retrospective study explored 56 patients undergoing tumor resection for malignant progression after previously treated IDH1-mutated WHO grade II astrocytoma. We analyzed survival after malignant progression, analyzed overall survival (OS), and identified prognostic factors using Kaplan-Meier estimates and log-rank test. Results By the time of malignant transformation, median age was 44 years, and median Karnofsky Performance Status (KPS) score was 90. Complete resection of contrast-enhancing tissue was achieved in 18 (32.1%) patients. Median survival after re-resection was 33 months (95% confidence interval [CI], 20–46); median OS was 123 months (95% CI, 77–170). Gross total tumor resection, postoperative KPS score ≥80, adjuvant radiochemotherapy, and prior radiotherapy significantly correlated with post-malignant progression survival. Conclusions Patients in good clinical condition with malignant progression of previously treated low-grade gliomas should receive aggressive treatment, including re-resection.