Glioma is one of the most common primary central nervous system (CNS) tumors, and its molecular diagnosis is crucial. However, surgical resection or biopsy is risky when the tumor is located deep in the brain or brainstem. In such cases, a minimally invasive approach to liquid biopsy is beneficial. Cell-free DNA (cfDNA), which directly reflects tumor-specific genetic changes, has attracted attention as a target for liquid biopsy, and blood-based cfDNA monitoring has been demonstrated for other extra-cranial cancers. However, it is still challenging to fully detect CNS tumors derived from cfDNA in the blood, including gliomas, because of the unique structure of the blood–brain barrier. Alternatively, cerebrospinal fluid (CSF) is an ideal source of cfDNA and is expected to contribute significantly to the liquid biopsy of gliomas. Several successful studies have been conducted to detect tumor-specific genetic alterations in cfDNA from CSF using digital PCR and/or next-generation sequencing. This review summarizes the current status of CSF-based cfDNA-targeted liquid biopsy for gliomas. It highlights how the approaches differ from liquid biopsies of other extra-cranial cancers and discusses the current issues and prospects.
胶质瘤是最常见的原发性中枢神经系统肿瘤之一，其分子诊断至关重要。然而，当肿瘤位于大脑深部或脑干时，手术切除或活检具有较高风险。在此类情况下，采用微创液体活检方法具有显著优势。游离DNA直接反映肿瘤特异性基因变化，已成为液体活检的重要靶标，基于血液的游离DNA监测技术已在颅外其他癌症中得到验证。但由于血脑屏障的特殊结构，从血液中完全检测包括胶质瘤在内的中枢神经系统肿瘤来源的游离DNA仍面临挑战。相比之下，脑脊液作为游离DNA的理想来源，有望在胶质瘤液体活检中发挥重要作用。目前已有研究通过数字PCR和/或新一代测序技术，成功检测到脑脊液游离DNA中的肿瘤特异性基因改变。本综述系统总结了基于脑脊液游离DNA的胶质瘤液体活检研究现状，重点阐述该方法与颅外癌症液体活检的差异，并探讨当前面临的挑战及未来发展方向。
Liquid Biopsy for Glioma Using Cell-Free DNA in Cerebrospinal Fluid
肿瘤(癌症)患者之家