Tunthanathip Thara, Sangkhathat Surasak, Kanjanapradit Kanet
Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
Department of Surgery, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
Asian J Neurosurg. 2022 Jun 1;17(1):3-10. doi: 10.1055/s-0042-1748789. eCollection 2022 Mar.
Malignant transformation (MT) of low-grade astrocytoma (LGA) triggers a poor prognosis in benign tumors. Currently, factors associated with MT of LGA have been inconclusive. The present study aims to explore the risk factors predicting LGA progressively differentiated to malignant astrocytoma. The study design was a retrospective cohort study of medical record reviews of patients with LGA. Using the Fire and Gray method, the competing risk regression analysis was performed to identify factors associated with MT, using both univariate and multivariable analyses. Hence, the survival curves of the cumulative incidence of MT of each covariate were constructed following the final model. Ninety patients with LGA were included in the analysis, and MT was observed in 14.4% of cases in the present study. For MT, 53.8% of patients with MT transformed to glioblastoma, while 46.2% differentiated to anaplastic astrocytoma. Factors associated with MT included supratentorial tumor (subdistribution hazard ratio [SHR] 4.54, 95% confidence interval [CI] 1.08-19.10), midline shift > 1 cm (SHR 8.25, 95% CI 2.18-31.21), and nontotal resection as follows: subtotal resection (SHR 5.35, 95% CI 1.07-26.82), partial resection (SHR 10.90, 95% CI 3.13-37.90), and biopsy (SHR 11.10, 95% CI 2.88-42.52). MT in patients with LGA significantly changed the natural history of the disease to an unfavorable prognosis. Analysis of patients' clinical characteristics from the present study identified supratentorial LGA, a midline shift more than 1 cm, and extent of resection as risk factors associated with MT. The more extent of resection would significantly help to decrease tumor burden and MT. In addition, future molecular research efforts are warranted to explain the pathogenesis of MT.
低级别星形细胞瘤（LGA）的恶性转化（MT）会导致良性肿瘤的预后不良。目前，与LGA的MT相关的因素尚无定论。本研究旨在探索预测LGA逐渐分化为恶性星形细胞瘤的危险因素。
研究设计为对LGA患者的病历进行回顾性队列研究。采用Fire和Gray方法，进行竞争风险回归分析以确定与MT相关的因素，同时进行单变量和多变量分析。因此，在最终模型之后构建了每个协变量的MT累积发病率的生存曲线。
90例LGA患者纳入分析，本研究中14.4%的病例观察到MT。对于MT，53.8%的MT患者转化为胶质母细胞瘤，而46.2%分化为间变性星形细胞瘤。与MT相关的因素包括幕上肿瘤（亚分布风险比[SHR] 4.54，95%置信区间[CI] 1.08 - 19.10）、中线移位>1 cm（SHR 8.25，95% CI 2.18 - 31.21）以及非全切除，具体如下：次全切除（SHR 5.35，95% CI 1.07 - 26.82）、部分切除（SHR 10.90，95% CI 3.13 - 37.90）和活检（SHR 11.10，95% CI 2.88 - 42.52）。
LGA患者的MT显著改变了疾病的自然史，使其预后不良。本研究对患者临床特征的分析确定幕上LGA、中线移位超过1 cm以及切除范围是与MT相关的危险因素。切除范围越大将显著有助于降低肿瘤负荷和MT。此外，未来有必要进行分子研究以解释MT的发病机制。
