Surgery for Recurrent High-Grade Glioma After Treatment with Bevacizumab

Use of Bevacizumab in recurrent glioblastoma: a scoping review and evidence map

BACKGROUND

Glioblastoma (GBM) is the most malignant primary tumor in the brain, with poor prognosis and limited effective therapies. Although Bevacizumab (BEV) has shown promise in extending progression-free survival (PFS) treating GBM, there is no evidence for its ability to prolong overall survival (OS). Given the uncertainty surrounding BEV treatment strategies, we aimed to provide an evidence map associated with BEV therapy for recurrent GBM (rGBM).

METHODS

PubMed, Embase, and the Cochrane Library were searched for the period from January 1, 1970, to March 1, 2022, for studies reporting the prognoses of patients with rGBM receiving BEV. The primary endpoints were overall survival (OS) and quality of life (QoL). The secondary endpoints were PFS, steroid use reduction, and risk of adverse effects. A scoping review and an evidence map were conducted to explore the optimal BEV treatment (including combination regimen, dosage, and window of opportunity).

RESULTS

Patients with rGBM could gain benefits in PFS, palliative, and cognitive advantages from BEV treatment, although the OS benefits could not be verified with high-quality evidence. Furthermore, BEV combined therapy (especially with lomustine and radiotherapy) showed higher efficacy than BEV monotherapy in the survival of patients with rGBM. Specific molecular alterations (IDH mutation status) and clinical features (large tumor burden and double-positive sign) could predict better responses to BEV administration. A low dosage of BEV showed equal efficacy to the recommended dose, but the optimal opportunity window for BEV administration remains unclear.

CONCLUSIONS

Although OS benefits from BEV-containing regimens could not be verified in this scoping review, the PFS benefits and side effects control supported BEV application in rGBM. Combining BEV with novel treatments like tumor-treating field (TTF) and administration at first recurrence may optimize the therapeutic efficacy. rGBM with a low apparent diffusion coefficient (ADCL), large tumor burden, or IDH mutation is more likely to benefit from BEV treatment. High-quality studies are warranted to explore the combination modality and identify BEV-response subpopulations to maximize benefits.

Delirium in neurosurgery: a systematic review and meta-analysis

Delirium is a frequent occurring complication in surgical patients. Nevertheless, a scientific work-up of the clinical relevance of delirium after intracranial surgery is lacking. We conducted a systematic review (CRD42020166656) to evaluate the current diagnostic work-up, incidence, risk factors and health outcomes of delirium in this population. Five databases (Embase, Medline, Web of Science, PsycINFO, Cochrane Central) were searched from inception through March 31st, 2021. Twenty-four studies (5589 patients) were included for qualitative analysis and twenty-one studies for quantitative analysis (5083 patients). Validated delirium screening tools were used in 70% of the studies, consisting of the Confusion Assessment Method (intensive care unit) (45%), Delirium Observation Screening Scale (5%), Intensive Care Delirium Screening Checklist (10%), Neelon and Champagne Confusion Scale (5%) and Nursing Delirium Screening Scale (5%). Incidence of post-operative delirium after intracranial surgery was 19%, ranging from 12 to 26% caused by variation in clinical features and delirium assessment methods. Meta-regression for age and gender did not show a correlation with delirium. We present an overview of risk factors and health outcomes associated with the onset of delirium. Our review highlights the need of future research on delirium in neurosurgery, which should focus on optimizing diagnosis and assessing prognostic significance and management.

Functional Outcomes and Health-Related Quality of Life Following Glioma Surgery

Functional outcome following glioma surgery is defined as how the patient functions or feels. Functional outcome is a coprimary end point of surgery in patients with diffuse glioma, together with oncological outcome. In this review, we structure the functional outcome measurements following glioma surgery as reported in the last 5 yr. We review various perspectives on functional outcome of glioma surgery with available measures, and offer suggestions for their use. From the recent neurosurgical literature, 160 publications were retrieved fulfilling the selection criteria. In these publications, neurological outcomes were reported most often, followed by activities of daily living, seizure outcomes, neurocognitive outcomes, and health-related quality of life or well-being. In more than a quarter of these publications functional outcome was not reported. A minimum essential consensus set of functional outcome measurements would benefit comparison across neurosurgical reports. The consensus set should be based on a combination of clinician- and patient-reported outcomes, assessed at a predefined time before and after surgery. The selected measurements should have psychometric properties supporting the intended use including validity-related evidence, reliability, and sensitivity to detect meaningful change with minimal burden to ensure compliance. We circulate a short survey as a start towards reporting guidelines. Many questions remain to better understand, report, and improve functional outcome following glioma surgery.

Recurrent high-grade glioma surgery: a multimodal intraoperative protocol to safely increase extent of tumor resection and analysis of its impact on patient outcome

OBJECTIVE

No consensus exists on the best treatment for recurrent high-grade glioma (HGG), particularly in terms of surgical indications, and scant data are available on the integrated use of multiple technologies to overcome intraoperative limits and pitfalls related to artifacts secondary to previous surgery and radiotherapy. Here, the authors report on their experience with the integration of multiple intraoperative tools in recurrent HGG surgery, analyzing their pros and cons as well as their effectiveness in increasing the extent of tumor resection. In addition, they present a review of the relevant literature on this topic.

METHODS

The authors reviewed all cases in which recurrent HGG had been histologically diagnosed after a first surgery and the patient had undergone a second surgery involving neuronavigation with MRI, intraoperative CT (iCT), 11C-methionine-positron emission tomography (11C-MET-PET), 5-aminolevulinic acid (5-ALA) fluorescence, intraoperative neurophysiological monitoring (IONM), and intraoperative navigated ultrasound (iUS). All cases were classified according to tumor functional grade (1, noneloquent area; 2, near an eloquent area; 3, eloquent area).

RESULTS

Twenty patients with recurrent HGG were operated on using a multimodal protocol. The recurrent tumor functional grade was 1 in 4 patients, 2 in 8 patients, and 3 in the remaining 8 patients. In all patients but 2, 100% EOTR was obtained. Intraoperative 5-ALA fluorescence and navigated iUS showed low specificity and sensitivity. iCT detected tumor remnants in 3 cases. Postoperatively, 6 patients (30%) had worsening neurological conditions: 4 recovered within 90 days, 1 partially recovered, and 1 experienced a permanent deficit. The median Karnofsky Performance Status remained substantially unchanged over the follow-up period. The mean progression-free survival after the second surgery was 7.7 months (range 2-11 months). The mean overall survival was 25.4 months (range 10-52 months), excluding 2 long survivors. Two patients died within 60 days after surgery, and 3 patients were still under follow-up at the end of this study.

CONCLUSIONS

This is the first study reporting the integration of neuronavigation, 5-ALA fluorescence, iUS, iCT, 11C-MET-PET, and IOM during microsurgical resection of recurrent glioma. The authors believe that the proposed multimodal protocol is useful to increase the safety, effectiveness, and EOTR in patients with recurrent HGG and brain alterations secondary to radio- and chemotherapy.

Downregulation of astrocyte elevated gene-1 expression inhibits the development of vasculogenic mimicry in gliomas

Vasculogenic mimicry (VM) contributes to the resistance of anti-angiogenic therapies in glioma. Certain genes, including MMP-2 and VEGF may be associated with the development of VM. Astrocyte elevated gene-1 (AEG-1) is considered to be an oncogene that promotes autophagy, invasion, metastasis, angiogenesis and drug resistance; however, the association between AEG-1 and VM formation is still unknown. The present study investigated the effects of AEG-1 downregulation on VM formation in the U87 glioma cell line in vitro and in xenograft models of glioma, and the potential underlying mechanisms of action. In the present study, U87 glioma cells were infected with the AEG-1 short hairpin RNA lentivirus. A Matrigel-based tube formation assay was performed to evaluate VM formation in vitro. Reverse transcription-quantitative PCR and western blot analysis were conducted to investigate the mRNA and protein expression levels of MMP-2 and VEGF. Glioma xenograft models were generated through the intracerebral implantation of U87 glioma cells into nude rats; CD34/Periodic Acid-Schiff double-staining was performed to detect VM channels in vivo. Following AEG-1 downregulation in U87 cells, the development of VM was significantly decreased in vitro and in vivo. In addition, the expression levels of MMP-2 and VEGF in glioma cells were decreased compared with the control group. These results suggested that downregulation of AEG-1 expression could significantly inhibit the development of VM in gliomas, both in vitro and in vivo, and may be partially related to the regulation of VEGF and MMP-2 expression.

Presence of Histopathological Treatment Effects at Resection of Recurrent Glioblastoma: Incidence and Effect on Outcome

BACKGROUND

Resection may be appropriate for select patients with recurrent glioblastoma. The incidence of histopathological findings related to prior treatment and their prognostic implications are incompletely characterized.

OBJECTIVE

To quantify the incidence and survival outcomes associated with treatment effect at resection of recurrent glioblastoma (GBM).

METHODS

Patients who underwent resection for recurrent GBM were retrospectively reviewed, and pathology, treatment history, and survival data were collected. Treatment effect was defined as any component of treatment-related changes on pathology.

RESULTS

In total, 110 patients underwent 146 reoperations. Median age at first reoperation was 57.2 yr and overall survival from reoperation was 10.8 mo. Treatment effect of any kind was noted in 81 of 146 reoperations (55%). Increased treatment effect was observed closer to radiotherapy; by quartile of time from radiotherapy, the rates of treatment effect were 77.8%, 55.6%, 40.7%, and 44.4% (P = .028). Treatment effect was associated with earlier reoperation (8.9 vs 13.8 mo after radiotherapy, P = .003), and the presence of treatment effect did not impact survival from primary surgery (25.4 vs 24.3 mo, P = .084). Patients treated with bevacizumab prior to reoperation were less likely to have treatment effect (20% vs 65%, P < .001).

CONCLUSION

Histopathological treatment-related changes are evident in a majority of patients undergoing resection for recurrent glioblastoma. There was no association of treatment effect with overall survival from primary surgery.

CircPCMTD1 Acts as the Sponge of miR-224-5p to Promote Glioma Progression

Glioma is the most common malignant tumor of the central nervous system with high morbidity and mortality. Circular RNAs (circRNAs) are abundant non-coding RNAs, which contribute to tumor progression by competing with other endogenous RNAs such as microRNA (miRNA). MiRNA are a class of small non-coding RNAs, which interrupt the translation of target mRNAs. CircPCMTD1 (hsa-circ-0001801) is a newly discovered circRNA that was found to be significantly upregulated in glioma. However, its function is unclear. In this study, circPCMTD1 upregulation promoted the cell viability, migration and invasion dramatically, while the inhibition of circPCMTD1 led to a significant reduction of tumor growth in vivo. MiRNAs microarray analyses on circPCMTD1 silencing models in U251 and U118MG cells were performed, and the results suggested that circPCMTD1 knockdown could upregulate the expression of miR-224-5p and downregulate the expression of mTOR, one of miR-224-5p targets, in both cell lines. According to the prediction from circular RNA interactome and Targetscan, there was a complementary sequence in circPCMTD1 for miR-224-5p. Dual-luciferase reporter assay demonstrated that circPCMTD1 were targets of miR-224-5p. RIP assay was also performed to further confirm their directly interaction. Overexpression of miR-224-5p inhibited the viability and proliferation, migration, and invasion of U251 and U118MG glioma cells. In conclusion, circPCMTD1 could contribute to the promotion of glioma progression, and it may serve as the sponge of miR-224-5p to exert its function.

Decreased circular RNA hsa_circ_0001649 predicts unfavorable prognosis in glioma and exerts oncogenic properties in vitro and in vivo

Glioma is a devastating disease with increasing incidence worldwide. Circular RNAs (circRNAs) was demonstrated to be involved in a wide range of pathophysiological processes, including tumorigenesis and development. Recently, the abnormally expressed hsa_circ_0001649 was found in several malignancies. In the current study, the expression levels of hsa_circ_0001649 in glioma and its clinical significance were explored. The biological functions including cell growth, colony-forming ability and apoptosis altered by hsa_circ_0001649 were further investigated in vitro. Tumor formation assay was also carried out to elucidate the oncogenic properties of hsa_circ_0001649. The data documented a decrease of hsa_circ_0001649 expression in glioma specimens and cell lines. In addition, down-regulated hsa_circ_0001649 is linked to larger tumor size (p = 0.002) and advanced WHO grade (p = 0.023). Additionally, hsa_circ_0001649 may be an independent prognostic marker for glioma patients after surgery (p = 0.046). Moreover, up-regulated hsa_circ_0001649 inhibits glioma cell growth in vitro and in vivo. Importantly, increased expression of hsa_circ_0001649 facilitates apoptosis by regulating Bcl-2/caspase-3 pathway. Ultimately, this study suggests that hsa_circ_0001649 may be a potential glioma-related prognostic/therapeutic target.