The Role of Surgery in IDH-Wild-Type Lower-Grade Gliomas: Threshold at a High Extent of Resection Should be Pursued.

Abstract

BACKGROUND\nWhile maximizing extent of resection (EOR) is associated with longer survival in lower-grade glioma (LGG) patients, the number of cases remains insufficient in determining a EOR threshold to elucidate the clinical benefits, especially in IDH-wild-type LGG patients.\n\n\nOBJECTIVE\nTo identify the effects of EOR on the survival outcomes of IDH-wild-type LGG patients.\n\n\nMETHODS\nIDH-wild-type LGG patients were retrospectively reviewed. The effect of EOR and other predictor variables on overall survival (OS) and progression-free survival (PFS) was analyzed using Cox regression models and the Kaplan-Meier method.\n\n\nRESULTS\nA total of 94 patients (median OS: 48.9 mo; median follow-up: 30.6 mo) were included in this study. In the multivariable Cox regression analysis, postoperative residual volume was associated with prolonged OS (HR\xa0=\xa02.238; 95% confidence interval [CI], 1.130-4.435; P\xa0=\xa0.021) and PFS (HR\xa0=\xa02.075; 95% CI, 1.113-3.869; P\xa0=\xa0.022). Thresholds at a minimum EOR of 97.0% or a maximum residue of 3.0\u2009cm3 were necessary to impact OS positively. For the telomerase reverse transcriptase (TERT)p-wild-type group, such an association was absent. Significant differences in survival existed between the TERTp-wild-type and mutant patients who underwent relatively incomplete resections (residual ≥2.0\u2009cm3\xa0+\xa0TERTp wild type: median OS of 62.6 mo [95% CI: 39.7-85.5 mo]; residual ≥2.0\u2009cm3\xa0+\xa0TERTp mutant: median OS of 20.0 mo [95% CI:14.6-25.4 mo]).\n\n\nCONCLUSION\nOur results support the core role of maximal safe resection in the treatment of IDH-wild-type LGGs, especially for IDH-wild-type\xa0+\xa0TERTp-mutant LGGs. Importantly, the survival benefits of surgery could only be elucidated at a high EOR cut-off point.