Epidemiology of adult meningioma: Report from the Dutch Brain Tumour Registry (2000-2019)

Application of Artificial Intelligence in Prediction of Ki-67 Index in Meningiomas: A Systematic Review and Meta-Analysis

BACKGROUND

The Ki-67 index is a histopathological marker that has been reported to be a crucial factor in the biological behavior and prognosis of meningiomas. Several studies have developed artificial intelligence (AI) models to predict the Ki-67 based on radiomics. In this study, we aimed to perform a systematic review and meta-analysis of AI models that predicted the Ki-67 index in meningioma.

METHODS

Literature records were retrieved on April 27, 2024, using the relevant key terms without filters in PubMed, Embase, Scopus, and Web of Science. Records were screened according to the eligibility criteria, and the data from included studies were extracted. The quality assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. The meta-analysis, sensitivity analysis, and meta-regression were conducted using R software.

RESULTS

Our study included 6 studies. The mean Ki-67 ranged from 2.7 ± 2.97 to 4.8 ± 40.3. Of 6 studies, 5 utilized a machine learning method. The most used AI method was the least absolute shrinkage and selection operator. The area under the curve and accuracy ranged from 0.83 to 0.99 and 0.81 to 0.95, respectively. AI models demonstrated a pooled sensitivity of 87.5% (95% confidence interval [CI]: 75.2%, 94.2%), a specificity of 86.9% (95% CI: 75.8%, 93.4%), and a diagnostic odds ratio of 40.02 (95% CI: 13.5, 156.4). The summary receiver operating characteristic curve indicated an area under the curve of 0.931 for the prediction of Ki-67 index status in intracranial meningiomas.

CONCLUSIONS

AI models have demonstrated promising performance for predicting the Ki-67 index in meningiomas and can optimize the treatment strategy.

Initial management of newly diagnosed WHO grade 2-3 adult meningioma following surgery: results from the Dutch Brain Tumour Registry (2016-2021)

PURPOSE

Meningiomas classified as grade 2-3 according to the World Health Organisation (WHO) require combined surgery and in most cases radiotherapy (RT). Their initial management was evaluated using the Dutch Brain Tumour Registry.

METHODS

The study included 393 patients aged ≥ 18 years with newly diagnosed meningioma WHO grade 2-3 between 2016 and 2021. Factors associated with adjuvant RT < 6 months following surgery were identified using logistic regression analyses, thereby accounting for variation between CNS regional tumour boards through mixed-effect modelling. This variation was further assessed by funnel plots for case-mix adjusted ratios of RT across tumour boards. The association with patients' survival at 5 years was evaluated with inverse probability-weighted accelerated failure (Weibull) models. Analyses were performed on multiple imputed datasets (m = 10) to account for missing data.

RESULTS

Adjuvant RT was administered to 22.2% (59/266) of patients with WHO grade 2 meningioma following a total resection, to 61.1% (58/95) following a partial resection, and to 68.8% (22/32) of patients with WHO grade 3 meningioma (61.5% after partial and 73.7% after total resection). RT was associated with grade 3, partial resection, bone invasion, and absence of multiple lesions. Management varied across tumour boards for grade 2 meningioma following total resection. Adjuvant RT was associated with survival benefit in case of grade 3 disease (hazard ratio: 0.40, 95%-confidence interval: 0.16-0.95, p = 0.04).

CONCLUSION

This national review revealed variation across CNS regional tumour boards in the management of grade 2 meningioma following total resection, and demonstrated survival benefit of adjuvant RT in grade 3 meningioma.

Oncogene-induced senescence in meningiomas-an immunohistochemical study

PURPOSE

Meningiomas are tumours originating from meningothelial cells, the majority belonging to grade 1 according to the World Health Organization classification of the tumours of the Central Nervous System. Factors contributing to the progression to the higher grades (grades 2 and 3) have not been elucidated yet. Senescence has been proposed as a potential mechanism constraining the malignant transformation of tumours. Senescence-associated beta-galactosidase (SA-β-GAL) and inhibitors of cyclin-dependent kinases p16 and p21 have been suggested as senescence markers.

METHODS

We analysed 318 meningiomas of total 343 (178 grade 1, 133 grade 2 and 7 grade 3). Tissue microarrays were constructed and stained immunohistochemically, using antibodies for SA-β-GAL, p16 and p21.

RESULTS

The positive correlation of the tumour grade with the expression of p16 (p = 0.016) and SA-β-GAL (p = 0.002) was observed. The expression of p16 and SA-β-GAL was significantly higher in meningiomas grade 2 compared to meningiomas grade 1 (p = 0.006 and p = 0.004, respectively). SA-β-GAL positivity positively correlated with p16 and p21 in the whole cohort. In grade 2 meningiomas, a positive correlation was only between SA-β-GAL and p16. Correlations of senescence markers in meningiomas grade 2 were not present.

CONCLUSION

Our findings suggest the senescence activation in meningiomas grade 2 as a potential mechanism for the restraining of tumour growth and give hope for applying of promising senolytic therapy.

Molecular prognostication in grade 3 meningiomas and p16/MTAP immunohistochemistry for predicting CDKN2A/B status

Background

The World Health Organization 2021 classification introduces molecular grading criteria for anaplastic meningiomas, including TERT promoter (TERTp) mutations and CDKN2A/B homozygous deletion. Additional adverse prognostic factors include H3K27me3 and BAP1 loss. The aim of this study was to explore whether these molecular alterations stratified clinical outcomes in a single-center cohort of grade 3 meningiomas. Additionally, we examined whether p16 and MTAP immunohistochemistry can predict CDKN2A/B status.

Methods

Clinical and histopathological information was obtained from the electronic medical records of grade 3 meningiomas resected at a tertiary center between 2007 and 2020. Molecular testing for TERTp mutations and CDKN2A/B copy-number status, methylation profiling, and immunohistochemistry for H3K27me3, BAP1, p16, and methylthioadenosine phosphorylase (MTAP) were performed. Predictors of survival were identified by Cox regression.

Results

Eight of 15 cases demonstrated elevated mitotic index (≥20 mitoses per 10 consecutive high-power fields), 1 tumor exhibited BAP1 loss, 4 harbored TERTp mutations, and 3 demonstrated CDKN2A/B homozygous deletion. Meningiomas with TERTp mutations and/or CDKN2A/B homozygous deletion showed significantly reduced survival compared to anaplastic meningiomas with elevated mitotic index alone. Immunohistochemical loss of p16 and MTAP demonstrated high sensitivity (67% and 100%, respectively) and specificity (100% and 100%, respectively) for predicting CDKN2A/B status.

Conclusions

Molecular alterations of grade 3 meningiomas stratify clinical outcomes more so than histologic features alone. Immunohistochemical loss of p16 and MTAP show promise in predicting CDKN2A/B status.