Survival trends of oligodendroglial tumor patients and associated clinical practice patterns: a SEER-based analysis

Abstract

There is limited information on the management strategies and survival trends for oligodendroglioma patients. Here we used the Surveillance, Epidemiology and End Results (SEER, 1999-2012) database to analyze the historical trends of oligodendroglioma patient survival and correlate these trends to evolving clinical practice of radiation therapy (RT) use and surgical practice of gross total resection (GTR). We identified 2689 World Health Organization (WHO) grade II oligodendroglioma (abbreviated as O2) and 1191 WHO grade III oligodendroglioma (abbreviated as O3). Time-trend analyses were performed for overall survival, radiation treatment (RT) use, and extent of surgical resection (EOR). In multivariable Cox models that accounted for age, race, sex, tumor size, tumor location, EOR, and RT status, the hazard of dying from O3 has significantly decreased over the study period (p < 0.01), while the hazard of dying from O2 has remained largely unchanged. A search of the published literature revealed articles reporting results largely supportive of these observations. The pattern of surgical practice and RT for O3 patients remained unchanged throughout the study period, suggesting that the survival improvement may be related to evolving patterns of medical management. Results from the SEER database indicate significant gains have been made in survival for O3 patients between 1999 and 2012. Such gains were not observed for O2 patients during this study period.

The Misclassification of Diffuse Gliomas: Rates and Outcomes

“…In addition, many of the key clinical trials of diffuse gliomas, as well as studies using historical cohorts, relied on older histology-only classification schemes. Nevertheless, the magnitude of potential coding errors and diagnostic misinterpretations in these databases are not fully appreciated or taken into consideration (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27).…”

Reflecting on survivorship outcomes to aid initial decision making in patients treated for IDH‐mutated anaplastic glioma

“…8 For a young patient with a predominantly nonenhancing tumor on magnetic resonance imaging (MRI), early intervention with RT may expose the individual to late neurocognitive deficits, and therefore an initial policy of observation may be adopted after craniotomy. The timing of these interventions historically has varied in relation to patient and tumor characteristics, especially if a tumor has been deemed to be lower or higher in grade in its radiological or pathological appearance.…”

“…10 Although the timing of the intervention remains uncertain, especially for patients with 1p19q codeleted tumors, the general conclusion has been for more aggressive combined adjuvant therapies to be performed earlier in the natural history of the tumor. 8,11,12 Therefore, the objective of the current study was to review the survivorship outcomes in a population of patients with IDH-mutated anaplastic glioma to determine the level of long-term functioning after management with RT and chemotherapy and examine those factors that may impact later adverse effects. 8,11,12 Therefore, the objective of the current study was to review the survivorship outcomes in a population of patients with IDH-mutated anaplastic glioma to determine the level of long-term functioning after management with RT and chemotherapy and examine those factors that may impact later adverse effects.…”

“…The timing of these interventions historically has varied in relation to patient and tumor characteristics, especially if a tumor has been deemed to be lower or higher in grade in its radiological or pathological appearance. 8 For a young patient with a predominantly nonenhancing tumor on magnetic resonance imaging (MRI), early intervention with RT may expose the individual to late neurocognitive deficits, and therefore an initial policy of observation may be adopted after craniotomy. Similarly, an attempt at maximal debulking to avoid RT may give rise to neurological deficits, which have an immediate impact on a patient's functional status, or potentially additive neurocognitive deficits if multiple craniotomies are required.…”

“…Knowledge of IDH mutation status now provides further prognostic information, but there remains uncertainty regarding management decisions including extent of surgical resection and timing of RT or chemotherapy. 8,11,12 Therefore, the objective of the current study was to review the survivorship outcomes in a population of patients with IDH-mutated anaplastic glioma to determine the level of long-term functioning after management with RT and chemotherapy and examine those factors that may impact later adverse effects.…”