Neuropathology Laboratory, Neurosciences Centre, All India Institute of Medical Sciences, New Delhi, India.
Department of Neuroradiology, All, India Institute of Medical Science, New Delhi, India.
Ann Diagn Pathol. 2024 Oct;72:152318. doi: 10.1016/j.anndiagpath.2024.152318. Epub 2024 Apr 23.
Pilocytic astrocytoma (PAs) represents a significant portion of childhood primary brain tumors, with distinct histological and radiological features. The prevalence of KIAA1549::BRAF fusion in PAs has been well-established, this study aims to assess the prevalence of KIAA1549::BRAF fusions and explore their associations with tumor characteristics, radiological findings, and patient outcomes in PAs.
Histologically confirmed cases of PAs from a 5-year period were included in the study. Demographic, histopathological, and radiological data were collected, and immunohistochemistry was performed to characterize tumor markers. FISH and qRT-PCR assays were employed to detect KIAA1549::BRAF fusions. Statistical analyses were conducted to examine associations between fusion status and various other parameters.
Histological analysis revealed no significant differences in tumor features based on fusion status. However, younger age groups showed higher fusion prevalence. Radiologically, fusion-positive cases were distributed across different tumor subtypes SE, CWE and NCWE. Survival analysis did not demonstrate a significant impact of fusion status on overall survival, however most cases with recurrence and death harboured KIAA1549::BRAF fusion. Of 200 PAs, KIAA1549::BRAF fusions were detected in 64 % and 74 % of cases via qRT-PCR and FISH, respectively. Concordance between the two platforms was substantial (86 %).
KIAA1549::BRAF fusions are prevalent in PAs and can be reliably detected using both FISH and qRT-PCR assays. Cost considerations suggest qRT-PCR as a more economical option for fusion detection in routine clinical practice.
毛细胞型星形细胞瘤（PA）是儿童原发性脑肿瘤的重要组成部分，具有独特的组织学和影像学特征。PA 中 KIAA1549::BRAF 融合的发生率已经得到了很好的证实，本研究旨在评估 KIAA1549::BRAF 融合的发生率，并探讨其与肿瘤特征、影像学表现和 PA 患者预后的关系。
本研究纳入了 5 年内经组织学证实的 PA 病例。收集了人口统计学、组织病理学和影像学数据，并进行了免疫组织化学分析以确定肿瘤标志物。采用 FISH 和 qRT-PCR 检测 KIAA1549::BRAF 融合。统计分析用于检验融合状态与其他参数之间的关联。
组织学分析显示，融合状态与肿瘤特征之间无显著差异。然而，年轻患者组的融合发生率较高。影像学上，融合阳性病例分布在不同的肿瘤亚型，包括 SE、CWE 和 NCWE。生存分析显示，融合状态对总生存率没有显著影响，但大多数复发和死亡的病例都存在 KIAA1549::BRAF 融合。在 200 例 PA 中，通过 qRT-PCR 和 FISH 分别检测到 64%和 74%的病例存在 KIAA1549::BRAF 融合。两种方法之间具有高度一致性（86%）。
KIAA1549::BRAF 融合在 PA 中较为常见，FISH 和 qRT-PCR 检测均可可靠检出。考虑到成本因素，qRT-PCR 是常规临床实践中融合检测更经济的选择。
