BACKGROUND Meningiomas are the most common group of adult central nervous system primary tumor. The major known predictors for meningioma recurrence are extent of surgical resection and histological grade. Although grading system is the actual standard for risk classification, there are several exceptions in the clinical behavior. Recent studies have shown that meningiomas can express PD-L1, a known therapeutic target for checkpoint inhibitors. Tumor microenvironment and hormonal setting are known to influence the immune system response. The only standard therapeutic strategies nowadays are surgery and radiotherapy. Meningiomas microenvironment needs to be further studied looking for new therapeutic targets. New prognostic tools combining histological and radiological features (RF) are needed to better address the treatment strategy. ELIGIBILITY CRITERIA Patients diagnosed with meningioma who underwent surgery at the Department of Neurosurgery of the IRCCS Ospedale Policlinico San Martino of Genoa from 1998. - Availability of magnetic resonance imaging (MRI) at diagnosis. - Availability of histological samples. OBJECTIVES Identification and prevalence of immune-related biomarkers and their correlation with morphological and hormonal features. - Survival analyses in the study population and according to the different characteristics analyzed. - The identification of specific clinical, histological and RF of meningiomas and their inclusion in a prognostic signature. STUDY DESIGN This is a retrospective-prospective monocentric study designed to analyze clinical, radiological and histological features of meningioma patients. - Clinical data will be collected from the electronic patient records. - Analyses will be conducted on a cohort of patients enriched with higher grade meningioma to balance the proportion between high and low grade histologies. - Histological specimen will be blindly reviewed and reclassified according to histological type, morphological features and WHO 2016 criteria. - The MRI features will be analyzed at diagnosis. STUDY ANALYSIS We retrospectively enrolled 50 patients with available radiological, histological and clinical data.- All histopathological specimens will be examined with slides obtained from material fixed in 10% neutral buffered formalin, included in kerosene, sectioned at 3 µm and stained with hematoxylin-eosin. - We will look for the presence of estrogens and progesterone receptors. - Concerning immune-related biomarkers we will further assess PD-L1 positivity (cut-off: positive 1%, negative <1%), MSI status and the inflammatory infiltrate with immunohistochemistry, in particular TILs (CD45, CD3, CD4, CD8, FOXP3, CTLA4), B cell (CD20), TAM (CD68). - All histological and radiological data will be analyzed and correlated with the clinical characteristics of meningioma patients and their outcomes.

中文翻译：

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P16.13 MenImmune：评估脑膜瘤中的免疫相关和预后生物标志物

背景脑膜瘤是成人中枢神经系统原发性肿瘤中最常见的一组。脑膜瘤复发的主要已知预测因素是手术切除范围和组织学分级。虽然分级系统是风险分类的实际标准，但在临床行为中也有一些例外。最近的研究表明，脑膜瘤可以表达 PD-L1，这是检查点抑制剂的已知治疗靶点。已知肿瘤微环境和激素环境会影响免疫系统反应。目前唯一的标准治疗策略是手术和放射治疗。脑膜瘤微环境需要进一步研究以寻找新的治疗靶点。需要结合组织学和放射学特征 (RF) 的新预后工具来更好地解决治疗策略。资格标准 自 1998 年起在热那亚的 IRCCS Ospedale Policlinico San Martino 神经外科接受手术的被诊断患有脑膜瘤的患者。 - 诊断时磁共振成像 (MRI) 的可用性。- 组织学样本的可用性。目标 免疫相关生物标志物的识别和流行及其与形态学和激素特征的相关性。- 研究人群中的生存分析，并根据分析的不同特征。- 识别脑膜瘤的特定临床、组织学和 RF 并将其纳入预后特征。研究设计 这是一项回顾性单中心研究，旨在分析脑膜瘤患者的临床、放射学和组织学特征。- 临床数据将从电子病历中收集。- 将对一组富含高级别脑膜瘤的患者进行分析，以平衡高级别和低级别组织学之间的比例。- 组织学标本将根据组织学类型、形态学特征和 WHO 2016 标准进行盲审和重新分类。- MRI 特征将在诊断时进行分析。研究分. - 我们将寻找雌激素和孕激素受体的存在。- 关于免疫相关生物标志物，我们将进一步评估 PD-L1 阳性（截止值：阳性 1%，阴性 <1%）、MSI 状态和免疫组织化学的炎症浸润，特别是 TIL（CD45、CD3、CD4、CD8 、FOXP3、CTLA4)、B 细胞 (CD20)、TAM (CD68)。- 将分析所有组织学和放射学数据并将其与脑膜瘤患者的临床特征及其结果相关联。