Hemorrhagic Outcome of Brainstem Cavernous Malformations following Radiosurgery: Dose-Response Relationship.

INTRODUCTION: This study aimed to assess the impact of gamma knife radiosurgery on brainstem cavernous malformations (CMs). METHODS: A total of 85 patients (35 females; median age 41.0 years) who underwent gamma knife radiosurgery for brainstem CMs at our institute between 2006 and 2015 were enrolled in a prospective clinical observation trial. Risk factors for hemorrhagic outcomes were evaluated, and outcomes were compared across different margin doses. RESULTS: The pre-radiosurgery annual hemorrhage rate (AHR) was 32.3% (44 hemorrhages during 136.2 patient-years). The median planning target volume was 1.292 cc. The median margin and maximum doses were 15.0 and 29.2 Gy, respectively, with a median isodose line of 50.0%. The post-radiosurgery AHR was 2.7% (21 hemorrhages during 769.9 patient-years), with a rate of 5.5% within the first 2 years and 2.0% thereafter. The post-radiosurgery AHR for patients with margin doses of ≤13.0 Gy (n = 15), 14.0-15.0 Gy (n = 50), and ≥16.0 Gy (n = 20) was 5.4, 2.7, and 0.6%, respectively. Correspondingly, transient adverse radiation effects were observed in 6.7 (1/15), 10.0 (5/50), and 30.0% (6/20) of cases, respectively. An increased margin dose per 1 Gy (hazard ratio: 0.530, 95% CI: 0.341-0.826, p = 0.005) was identified as an independent protective factor against post-radiosurgery hemorrhage. Margin doses of ≥16.0 Gy were associated with improved hemorrhagic outcomes (hazard ratio: 0.343, 95% confidence interval [CI]: 0.157-0.749, p = 0.007), but an increased risk of adverse radiation effects (odds ratio: 3.006, 95% CI: 1.041-8.677, p = 0.042). CONCLUSION: The AHR of brainstem CMs decreased following radiosurgery, and our study revealed a significant dose-response relationship. Margin doses of 14-15 Gy were recommended. Further studies are required to validate our findings.

Function and regulation of miR-186-5p, miR-125b-5p and miR-1260a in chordoma.

BACKGROUND: The function and regulation of miRNAs in progression of chordoma were unclear. METHODS: Five miRNAs were identified by the machine learning method from the miRNA expression array. CCk-8 assay, EDU assay, wound healing migration assay, and trans-well assay were used to reveal the effect of the miRNAs in chordoma cell lines. Moreover, bioinformation analysis and the mRNA expression array between the primary chordomas and recurrent chordomas were used to find the target protein genes of miRNAs. Furthermore, qRT-PCR and luciferase reporter assay were used to verify the result. RESULTS: miR-186-5p, miR-30c-5p, miR-151b, and miR-125b-5p could inhibit proliferation, migration, and invasion of chordoma while miR-1260a enhances proliferation, migration, and invasion of chordoma. Recurrent chordoma has a worse disease-free outcome than the primary chordoma patients. AMOT, NPTX1, RYR3, and P2RX5 were the target protein mRNAs of miR-186-5p; NPTX1 was the target protein mRNAs of miR-125b-5p; and AMOT and TNFSF14 were the target protein mRNAs of miR-1260a. CONCLUSIONS: miR-186-5p, miR-125b-5p, miR-1260a, and their target protein mRNAs including AMOT, NPTX1, RYR3, P2RX5, TNFSF14 may be the basement of chordoma research.

Unravelling the role of immune cells and FN1 in the recurrence and therapeutic process of skull base chordoma.

BACKGROUND: Skull base chordoma is a rare and aggressive tumour of the bone that has a high likelihood of recurrence. The fundamental differences in single cells between primary and recurrent lesions remain poorly understood, impeding development of effective treatment approaches. METHODS: To obtain an understanding of the differences in single cells between primary and recurrent chordomas, we performed single-cell RNA sequencing and T-cell/B-cell receptor (BCR) sequencing. This allowed us to delineate the differences between the two types of tumour cells, tumour-infiltrating lymphocytes, myeloid cells, fibroblasts and B cells. Copy number variants (CNVs) were detected and compared between the tumour types to assess heterogeneity. Selected samples were subjected to immunohistochemistry to validate protein expression. Fluorescence in situ hybridisation experiments, Transwell assays and xenograft mouse models helped verify the role of fibronectin 1 (FN1) in chordoma. RESULTS: Promoting natural killer (NK) cell and CD8_GZMK T-cell function or inhibiting the transformation of CD8_GZMK T cells to CD8_ZNF683 T cells and promoting the transformation of natural killer T (NKT) cells to NK cells are promising strategies for preventing chordoma recurrence. Additionally, inhibiting the M2-like activity of tumour-associated macrophages (TAMs) could be an effective approach. Antigen-presenting cancer-associated fibroblasts (apCAFs) and dendritic cells (DCs) with high enrichment of the antigen-presenting signature were enriched in primary chordomas. There were fewer plasma cells and BCR clonotypes in recurrent chordomas. Remarkably, FN1 was upregulated, had more CNVs, and was more highly secreted by tumours, macrophages, CD4 T cells, CD8 T cells and fibroblasts in recurrent chordoma than in primary chordoma. Finally, FN1 enhanced the invasion and proliferation of chordomas in vivo and in vitro. CONCLUSION: Our comprehensive picture of the microenvironment of primary and recurrent chordomas provides deep insights into the mechanisms of chordoma recurrence. FN1 is an important target for chordoma therapy.

Extra-axial cavernous malformations of the foramen magnum: illustrative cases.

BACKGROUND: Extra-axial cavernous malformations involving the foramen magnum are rare, and preoperative diagnosis becomes difficult when they mimic meningiomas. OBSERVATIONS: The authors present 2 cases of extra-axial cavernous malformations involving the foramen magnum. Surgical removal of the lesions was performed via far lateral craniotomy. The authors investigate the disease and elaborate the differential diagnosis. LESSONS: The authors recommend that extra-axial cavernous malformations should be considered in the differential diagnosis of lesions in the foramen magnum region. Intraoperative frozen sections are helpful to the diagnosis, and resection warranted a favorable long-term outcome.

Rosai-Dorfman Disease in the Skull Base: A Case Series Study.

OBJECTIVE: Rosai-Dorfman disease (RDD) is a rare, idiopathic, and non-neoplastic histio-proliferative disease that is uncommon in the central nervous system. Hence, reports of management of RDD in the skull base are scarce and only a few studies on skull base RDD are available. The objective of this study was to analyze the diagnosis, treatment, and prognosis of RDD in the skull base and explore an appropriate treatment strategy thereof. METHODS: Nine patients with clinical characteristics and follow-up data from our department between 2017 and 2022 were included in this study. From this information, the clinical profiles, imaging, treatment, and prognosis data were collected. RESULTS: There were 6 male and 3 female patients with skull base RDD. These patients ranged in age from 13 to 61 years, with a median age of 41 years. The locations included 1 anterior skull base orbital apex, 1 parasellar region, 2 sellar regions, 1 petroclivus, and 4 foramen magnum regions. Six patients underwent total resection and 3 underwent subtotal resection. Patient follow-up lasted 11-65 months, with a median duration of 24 months. One patient died, 2 experienced recurrence, and the other patients' lesions were stable. The symptoms worsened and new complications occurred in 5 patients. CONCLUSIONS: Skull base RDDs are intractable diseases with a high rate of complications. Some patients are at risk of recurrence and death. Surgery may be the basic treatment for this disease, and combined therapy including targeted therapy or radiation therapy may also be a valuable therapeutic strategy.

Methylation-based reclassification and risk stratification of skull-base chordomas.

Background: Skull-base chordomas are rare malignant bone cancers originating from the remnant of the notochord. Survival is variable, and clinical or molecular factors cannot reliably predict their outcomes. This study therefore identified epigenetic subtypes that defined new chordoma epigenetic profiles and their corresponding characteristics. Methods: Methylation profiles of 46 chordoma-resected neoplasms between 2008 and 2014, along with clinical information, were collected. K-means consensus clustering and principal component analysis were used to identify and validate the clusters. Single-sample gene set enrichment analysis, methylCIBERSORT algorithm, and copy number analysis were used to identify the characteristics of the clusters. Results: Unsupervised clustering analysis confirmed two clusters with a progression-free survival difference. Gene set enrichment analysis indicated that the early and late estrogen response pathways and the hypoxia pathway were activated whereas the inflammatory and interferon gamma responses were suppressed. Forty-six potential therapeutic targets corresponding to differentially methylated sites were identified from chordoma patients. Subgroups with a worse outcome were characterized by low immune cell infiltration, higher tumor purity, and higher stemness indices. Moreover, copy number amplifications mostly occurred in cluster 1 tumors and the high-risk group. Additionally, the presence of a CCNE1 deletion was exclusively found in the group of chordoma patients with better outcome, whereas RB1 and CDKN2A/2B deletions were mainly found in the group of chordoma patients with worse outcome. Conclusions: Chordoma prognostic epigenetic subtypes were identified, and their corresponding characteristics were found to be variable.