Next generation sequencing identifies novel potential actionable mutations for grade I meningioma treatment

Next-Generation DNA Sequencing of Grade 1 Meningioma Tumours: A Case Report of Angiomatous and Psammomatous Meningiomas

We performed the next-generation sequencing (NGS) analysis of a rare grade 1 brain meningioma (angiomatous type) and a common grade 1 spinal meningioma (psammomatous type) and compared their mutation profiling. The data were analysed using the Ion Reporter 5.16 programme (Thermo Fisher Scientific, Waltham, MA). Sequencing analysis identified 10 novel variants and two previously reported variants that were common between these two tumours. Nine variants were missense, which included an insertion in EGFR c.1819_1820insCA, causing frameshifting, and a single nucleotide deletion in HRAS and HNF1A genes, causing frameshifting in these genes. These were common variants identified for both tumours. Also, 10 synonymous variants and 10 intronic variants were common between these two tumours. In intronic variants, two were splice site_5' variants (acceptor site variants). Typical of the angiomatous type tumour, there were 11 novel and six previously reported variants that were not found in the psammomatous tumour; three variants were synonymous, 11 were missense mutations, and three were deletions causing frameshifting. The deletion variants were in the SMARCB1, CDH1, and KDR genes. In contrast, eight novel and five previously reported variants were found in the psammomatous meningioma tumour. In this tumour, two variants were synonymous: a deletion causing a frameshifting in [(c.3920delT; p. (Ile1307fs)], and a two-base pair insertion and deletion (INDEL) [(c.3986_3987delACinsGT; p. (His1329Arg)] both in the APC gene were also found. Among our findings, we have identified that ALK, VHL, CTNNB1, EGFR, ERBB4, PDGFRA, KDR, SMO, ABL1, HRAS, ATM, HNF1A, FLT3, and RB1 mutations are common for psammomatous meningioma and angiomatous tumours. Variants typical for angiomatous (brain) meningioma are PIK3CA, KIT, PTPN11, CDH1, SMAD4, and SMARCB1; the variants typical for psammomatous meningioma are APC, FGFR2, HNF1A, STK11, and JAK3. The RET splice variant (c.1880-2A>C) found in both meningioma tumours is reported (rs193922699) as likely pathogenic in the Single Nucleotide Polymorphism Database (dbSNP). All missense variants detected in these two meningiomas are found in the cancer-driver genes. The eight variants we found in genes such as EGFR, PDGFRA, SMO, FLT3, PIK3CA, PTPN11, CDH1, and RB1 are glioma-driver genes. We did not find any mutations in genes such as BRAF, IDH1, CDKN2A, PTEN, and TP53, which are also listed as cancer-driver genes in gliomas. Mutation profiling utilising NGS technology in meningiomas could help in the accurate diagnosis and classification of these tumours and also in developing more effective treatments.

A novel BRAF::PTPRN2 fusion in meningioma: a case report

Gene fusion events have been linked to oncogenesis in many cancers. However, gene fusions in meningioma are understudied compared to somatic mutations, chromosomal gains/losses, and epigenetic changes. Fusions involving B-raf proto-oncogene, serine/threonine kinase (BRAF) are subtypes of oncogenic BRAF genetic abnormalities that have been reported in certain cases of brain tumors, such as pilocytic astrocytomas. However, BRAF fusions have not been recognized in meningioma. We present the case of an adult female presenting with episodic partial seizures characterized by déjà vu, confusion, and cognitive changes. Brain imaging revealed a cavernous sinus and sphenoid wing mass and she underwent resection. Histopathology revealed a World Health Organization (WHO) grade 1 meningioma. Genetic profiling with next generation sequencing and microarray analysis revealed an in-frame BRAF::PTPRN2 fusion affecting the BRAF kinase domain as well as chromothripsis of chromosome 7q resulting in multiple segmental gains and losses including amplifications of cyclin dependent kinase 6 (CDK6), tyrosine protein-kinase Met (MET), and smoothened (SMO). Elevated pERK staining in tumor cells provided evidence of activated mitogen-activated protein kinase (MAPK) signaling. This report raises the possibility that gene fusion events may be involved in meningioma pathogenesis and warrant further investigation.

Clinicopathological significance of concurrent ErbB receptor expression in human meningioma

In general, human meningiomas grow slowly and have a favourable prognosis; however, some are prone to recur despite their benign histology. Therefore, knowledge of their tumour biology is essential to determine objective biomarkers that can identify cases with an increased risk for recurrence and to generate effective treatment options. Thus, studies on the epidermal growth factor receptor (EGFR) family, comprising ErbB1/EGFR, ErbB2/HER2, ErbB3/HER3 and ErbB4/HER4, are important. We have recently published papers on the expression of each of these receptor proteins in human meningiomas. The present study aimed to assess the clinicopathological significance of their concurrent expression. A total of 185 grade 1 and 2 meningiomas with robust clinical data underwent immunohistochemical analyses with antibodies against the aforementioned receptors. All meningiomas exhibited upregulation of these receptor proteins relative to normal meninges. In addition, the expression of phosphorylated/activated ErbB1/EGFR1 and phosphorylated/activated ErbB2/HER2 was significantly associated with histological malignancy grade and prognosis, respectively. The concurrent upregulation of ErbB receptors in human meningioma supports their fundamental role in the tumourigenesis of these tumours, and they could thus be exploited in diagnostics, prognosis, and ultimately, in targeted clinical interventions.

Multiple meningiomas arising within the same hemisphere associated with Li-Fraumeni syndrome

Background:

While meningiomas are some of the most common intracranial tumors, the presence of multiple ones at the time of presentation is rare and can most commonly be observed in patients with well-described syndromes (i.e., neurofibromatosis type 2) or those with prior cranial radiation history. In others, however, the pathophysiology remains unclear.

Case Description:

A 49-year-old female with no significant personal or familial oncologic medical history presented with a generalized seizure and was found to have ten meningiomas arising within the right hemisphere. She underwent a two-staged resection of all tumors, with pathology revealing the World Health Organization Grade I meningioma. Whole-exome sequencing revealed somatic NF2 mutations and heterozygous deletion of chromosome 22 overlapping with NF2, and analysis of the germline uncovered mutations of TP53, rendering a diagnosis of Li-Fraumeni Syndrome.

Conclusions:

This case represents a novel presentation of multiple meningiomas in a patient with newly diagnosed Li-Fraumeni syndrome, suggesting meningioma may be considered as part of this tumor-predisposed patient population.

SWI/SNF chromatin remodeling complex alterations in meningioma

PURPOSE

While SWI/SNF chromatin remodeling complex alterations occur in approximately 20% of cancer, the frequency and potential impact on clinical outcomes in meningiomas remains to be comprehensively elucidated.

METHODS

A large series of 255 meningiomas from a single institution that was enriched for high grade and recurrent lesions was identified. We performed next-generation targeted sequencing of known meningioma driver genes, including NF2, AKT1, PIK3CA, PIK3R1, and SMO and SWI/SNF chromatin remodeling complex genes, including ARID1A, SMARCA4, and SMARCB1 in all samples. Clinical correlates focused on clinical presentation and patient outcomes are presented.

RESULTS

The series included 63 grade I meningiomas and 192 high-grade meningiomas, including 173 WHO grade II and 19 WHO grade III. Samples from recurrent surgeries comprised 37.3% of the series. A total of 41.6% meningiomas were from the skull base. NF2, AKT1, PIK3CA, PIK3R1, and SMO were mutated in 40.8, 7.1, 3.5, 3.9, and 2.4% of samples, respectively. ARID1A, SMARCA4, and SMARCB1 mutations were observed in 17.3, 3.5, and 5.1% of samples, respectively. A total of 68.2% of ARID1A-mutant meningiomas harbored a p.Gln1327del in-frame deletion. ARID1A mutations were seen in 19.1% of Grade I, 16.8% of Grade II, and 15.8% of Grade III meningiomas (P = 0.9, Fisher's exact). Median overall survival was 16.3 years (95% CI 10.9, 16.8). With multivariable analysis, the presence of an ARID1A mutation was significantly associated with a 7.421-fold increased hazard of death (P = 0.04).

CONCLUSION

ARID1A mutations occur with similar frequency between low and high-grade meningiomas, but ARID1A mutations are independently prognostic of worse prognosis beyond clinical and histopathologic features.

Distinct genomic subclasses of high-grade/progressive meningiomas: NF2-associated, NF2-exclusive, and NF2-agnostic

BACKGROUND

Genomic studies of high-grade/progressive meningiomas have reported a heterogeneous mutation spectrum, identifying few recurrently mutated genes. Most studies have been underpowered to detect genomic subclasses of aggressive meningiomas due to relatively small number of available samples. Here, we present a genomic survey of one of the largest multi-institutional cohorts of high-grade/progressive meningiomas to date.

METHODS

850 high-grade/progressive meningiomas, including 441 WHO grade 2 and 176 WHO grade 3 meningiomas and 220 progressive WHO grade 1 meningiomas, were tested as part of a clinical testing program by hybridization capture of 406 cancer-related genes to detect base substitutions, indels, amplifications, deletions, and rearrangements. Information from pathology reports, histopathology review, and patient clinical data was assessed.

RESULTS

Genomic analyses converged to identify at least three distinct patterns of biologically-aggressive meningiomas. The first and most common contained NF2-mutant tumors (n = 426, 50%), was associated with male sex (64.4% %, p = 0.0001) and often harbored additional mutations in CDKN2A/B (24%), and the chromatin regulators ARID1A (9%), and KDM6A (6%). A second group (NF2-agnostic) featured TERT promoter (TERTp; n = 56) or TP53 mutations (n = 25) and were either NF2-mutant or wild-type, and displayed no association with either sex (p = 0.39). The remaining group generally lacked NF2 mutations, and accounted for 40% of the cases-with three subgroups. One consistent primarily of grade 3 lesions harboring alterations in chromatin regulators BAP1 (n = 22) or PBRM1 (n = 16). A second subgroup contained AKT1 (n = 26), PIK3CA (n = 14) and SMO (n = 7) mutant skull-based meningiomas, and a third mixed subgroup included 237 meningiomas with a heterogeneous spectrum of low frequency and non-recurrent alterations.

CONCLUSIONS

Our findings indicate that the patterns of genomic alterations in high-grade/progressive meningiomas commonly group into three different categories. The most common NF2-associated canonical group frequently harbored CDKN2A/B alterations, which is potentially amenable to targeted therapies. An NF2-agnostic group harbored frequent TERTp and TP53 mutations. The final subclass, distinct from the canonical NF2 mutant associated pathway, was partly characterized by BAP1/PBRM1 alterations (rhabdoid/papillary histology) or skull-base disease. Overall, these data increase our understanding of the pathobiology of high-grade/progressive meningiomas and can guide the design of clinical trials.

IRB APPROVAL STATUS

Reviewed and approved by Western IRB; Protocol No. 20152817.

STK11 mutation status is associated with decreased survival in meningiomas

BACKGROUND

Emerging evidence suggests that STK11 mutations may influence clinical outcome and response to immunotherapy in cancer.

MATERIALS AND METHODS

Next-generation targeted sequencing of STK11 mutation status in a large cohort of 188 meningiomas.

RESULTS

STK11 loss-of-function mutations were identified in 3.7% of meningiomas. STK11 mutations were found in both low- and high-grade lesions and samples from primary and recurrent disease. There was a 2.8-fold increased risk of death for patients whose meningioma harbored an STK11 mutation, after controlling for lesion grade and occurrence status. The median overall survival for patients with STK11-mutated meningiomas was 4.4 years compared with 16.8 years.

CONCLUSION

These data identify recurrent STK11 mutations in a subset of meningiomas. Genotyping of STK11 is encouraged for meningioma patients undergoing immunotherapy-based therapy.