Management of Elderly Patients with Glioblastoma

An online survival predictor in glioma patients using machine learning based on WHO CNS5 data

Background

The World Health Organization (WHO) CNS5 classification system highlights the significance of molecular biomarkers in providing meaningful prognostic and therapeutic information for gliomas. However, predicting individual patient survival remains challenging due to the lack of integrated quantitative assessment tools. In this study, we aimed to design a WHO CNS5-related risk signature to predict the overall survival (OS) rate of glioma patients using machine learning algorithms.

Methods

We extracted data from patients who underwent an operation for histopathologically confirmed glioma from our hospital database (2011-2022) and split them into a training and hold-out test set in a 7/3 ratio. We used biological markers related to WHO CNS5, clinical data (age, sex, and WHO grade), and prognosis follow-up information to identify prognostic factors and construct a predictive dynamic nomograph to predict the survival rate of glioma patients using 4 kinds machine learning algorithms (RF, SVM, XGB, and GLM).

Results

A total of 198 patients with complete WHO5 molecular data and follow-up information were included in the study. The median OS time of all patients was 29.77 [95% confidence interval (CI): 21.19-38.34] months. Age, FGFR2, IDH1, CDK4, CDK6, KIT, and CDKN2A were considered vital indicators related to the prognosis and OS time of glioma. To better predict the prognosis of glioma patients, we constructed a WHO5-related risk signature and nomogram. The AUC values of the ROC curves of the nomogram for predicting the 1, 3, and 5-year OS were 0.849, 0.835, and 0.821 in training set, and, 0.844, 0.943, and 0.959 in validation set. The calibration plot confirmed the reliability of the nomogram, and the c-index was 0.742 in training set and 0.775 in validation set. Additionally, our nomogram showed a superior net benefit across a broader scale of threshold probabilities in decision curve analysis. Therefore, we selected it as the backend for the online survival prediction tool (Glioma Survival Calculator, https://who5pumch.shinyapps.io/DynNomapp/), which can calculate the survival probability for a specific time of the patients.

Conclusion

An online prognosis predictor based on WHO5-related biomarkers was constructed. This therapeutically promising tool may increase the precision of forecast therapy outcomes and assess prognosis.

Is there a limited value of cytoreductive surgery in elderly patients with malignant gliomas?

Background:

Glioblastoma (GB) is well known for being the most aggressive primary cerebral malignancy. The peak incidence is at 60–70 years of age, with over half of patients aged over 65 years at diagnosis.

Methods:

Patients with a confirmed histological diagnosis of GB between January 2009 and June 2016 at a single center were retrospectively identified. The inclusion criteria for the study were age over 65 years at diagnosis, and surgical management with either a burr hole biopsy or craniotomy.

Results:

A total of n = 289 patients underwent surgery for GB, with a median age at diagnosis of 71 years, and of whom 64% were male. Craniotomies were performed in 71%, with burr hole biopsies performed in the remainder (29%). Patient survival differed significantly with treatment modality (P < 0.001), ranging from a median of 382 days in those treated with a combination of craniotomy, radiotherapy (RT), and temozolomide (TZM), to 43 days in those only receiving a burr hole biopsy with no further treatment. On multivariable analysis, treatment with RT + TZM was significantly independently associated with longer patient survival (P < 0.001). Craniotomy was associated with a significant improvement in performance status, compared to burr hole biopsy (P = 0.006). For the subgroup of patients receiving TZM, those with a methylated O⁶-methylguanine-DNA-methyltransferase (MGMT) status had significantly longer overall survival than those with unmethylated MGMT (median: 407 vs. 341 days, P = 0.039).

Conclusion:

Our retrospective data demonstrate that the elderly population with GB benefit from aggressive chemo-RT, regardless of surgical intervention.

Age-adjusted Charlson comorbidity index in recurrent glioblastoma: a new prognostic factor?

Background

For recurrent glioblastoma (GB) patients, several therapy options have been established over the last years such as more aggressive surgery, re-irradiation or chemotherapy. Age and the Karnofsky Performance Status Scale (KPSS) are used to make decisions for these patients as these are established as prognostic factors in the initial diagnosis of GB. This study’s aim was to evaluate preoperative patient comorbidities by using the age-adjusted Charlson Comorbidity Index (ACCI) as a prognostic factor for recurrent GB patients.

Methods

In this retrospective analysis we could include 123 patients with surgery for primary recurrence of GB from January 2007 until December 2016 (43 females, 80 males, mean age 57 years (range 21–80 years)). Preoperative age, sex, ACCI, KPSS and adjuvant treatment regimes were recorded for each patient. Extent of resection (EOR) was recorded as a complete/incomplete resection of the contrast-enhancing tumor part.

Results

Median overall survival (OS) was 9.0 months (95% CI 7.1–10.9 months) after first re-resection. Preoperative KPSS > 80% (P < 0.001) and EOR (P = 0.013) were associated with significantly improved survival in univariate analysis. Including these factors in multivariate analysis, preoperative KPSS < 80 (HR 2.002 [95% CI: 1.246–3.216], P = 0.004) and EOR are the only significant prognostic factor (HR 1.611 [95% CI: 1.036–2.505], P = 0.034). ACCI was not shown as a prognostic factor in univariate and multivariate analyses.

Conclusion

For patients with surgery for recurrent glioblastoma, the ACCI does not add further information about patient’s prognosis besides the well-established KPSS and extent of resection.

Pharmacologically inhibiting phosphoglycerate kinase 1 for glioma with NG52

Inhibition of glycolysis process has been an attractive approach for cancer treatment due to the evidence that tumor cells are more dependent on glycolysis rather than oxidative phosphorylation pathway. Preliminary evidence shows that inhibition of phosphoglycerate kinase 1 (PGK1) kinase activity would reverse the Warburg effect and make tumor cells lose the metabolic advantage for fueling the proliferation through restoration of the pyruvate dehydrogenase (PDH) activity and subsequently promotion of pyruvic acid to enter the Krebs cycle in glioma. However, due to the lack of small molecule inhibitors of PGK1 kinase activity to treat glioma, whether PGK1 could be a therapeutic target of glioma has not been pharmacologically verified yet. In this study we developed a high-throughput screening and discovered that NG52, previously known as a yeast cell cycle-regulating kinase inhibitor, could inhibit the kinase activity of PGK1 (the IC50 = 2.5 ± 0.2 μM). We showed that NG52 dose-dependently inhibited the proliferation of glioma U87 and U251 cell lines with IC50 values of 7.8 ± 1.1 and 5.2 ± 0.2 μM, respectively, meanwhile it potently inhibited the proliferation of primary glioma cells. We further revealed that NG52 (12.5-50 μM) effectively inhibited the phosphorylation of PDHK1 at Thr338 site and the phosphorylation of PDH at Ser293 site in U87 and U251 cells, resulting in more pyruvic acid entering the Krebs cycle with increased production of ATP and ROS. Therefore, NG52 could reverse the Warburg effect by inhibiting PGK1 kinase activity, and switched cellular glucose metabolism from anaerobic mode to aerobic mode. In nude mice bearing patient-derived glioma xenograft, oral administration of NG52 (50, 100, 150 mg· kg-1·d-1, for 13 days) dose-dependently suppressed the growth of glioma xenograft. Together, our results demonstrate that targeting PGK1 kinase activity might be a potential strategy for glioma treatment.

Rapid Early Tumor Progression is Prognostic in Glioblastoma Patients

OBJECTIVES

Determine the prognostic significance of rapid early tumor progression before radiation and chemotherapy for glioblastoma patients.

METHODS

A retrospective review of glioblastoma patients was performed. Rapid early progression (REP) was defined as new enhancing tumor or >25% increase in enhancement before radiotherapy. The pre/postoperative magnetic resonance imaging was compared with the preradiation magnetic resonance imaging to determine REP. A blinded review of imaging was performed. Kaplan-Meier curves were generated to compare progression-free and overall survival (OS). Univariate analysis was performed using the log-rank test for categorical variables and Cox proportional hazards for continuous variables. Multivariable logistic regression was performed to assess factors related to early progression and Cox proportional hazards model was used for multivariate analysis of OS.

RESULTS

Eighty-seven patients met entry criteria. A total of 52% of patients developed REP. The OS in the REP group was 11.5 months (95% confidence interval [CI]: 7.4-17.6) and 20.1 months (95% CI: 17.8-26.1) without REP (P=0.013). On multivariate analysis including significant prognostic factors, presence of REP was found to increase the risk of death (hazard ratio: 2.104, 95% CI: 1.235-3.583, P=0.006). A total of 74% of patients recurred in the site of REP.

CONCLUSIONS

REP was common and independently predicted for a worse OS. Integrating REP with MGMT promotor methylation improved prognostic assessment. The site of REP was a common site of tumor progression. Our findings are hypothesis generating and may indicate a particular subset of glioblastoma patients who are resistant to current standard of care therapy. Further study to determine other molecular features of this group are underway.

Radiotherapy of Glioblastoma 15 Years after the Landmark Stupp's Trial: More Controversies than Standards?

Background

The current standard of care of glioblastoma, the most common primary brain tumor in adults, has remained unchanged for over a decade. Nevertheless, some improvements in patient outcomes have occurred as a consequence of modern surgery, improved radiotherapy and up-to-date management of toxicity. Patients from control arms (receiving standard concurrent chemoradiotherapy and adjuvant chemotherapy with temozolomide) of recent clinical trials achieve better outcomes compared to the median survival of 14.6 months reported in Stupp’s landmark clinical trial in 2005. The approach to radiotherapy that emerged from Stupp’s trial, which continues to be a basis for the current standard of care, is no longer applicable and there is a need to develop updated guidelines for radiotherapy within the daily clinical practice that address or at least acknowledge existing controversies in the planning of radiotherapy.

The goal of this review is to provoke critical thinking about potentially controversial aspects in the radiotherapy of glioblastoma, including among others the issue of target definitions, simultaneously integrated boost technique, and hippocampal sparing.

Conclusions

In conjunction with new treatment approaches such as tumor-treating fields (TTF) and immunotherapy, the role of adjuvant radiotherapy will be further defined. The personalized approach in daily radiotherapy practice is enabled with modern radiotherapy systems.

Glioblastoma update: molecular biology, diagnosis, treatment, response assessment, and translational clinical trials

This is an exciting time in neuro-oncology. Discoveries elucidating the molecular mechanisms of oncogenesis and the molecular subtypes of glioblastoma multiforme (GBM) have led to new diagnostic and classification schemes with more prognostic power than histology alone. Molecular profiling has become part of the standard neuropathological evaluation of GBM. Chemoradiation followed by adjuvant temozolomide remains the standard therapy for newly diagnosed GBM, but survival remains unsatisfactory. Patients with recurrent GBM continue to have a dismal prognosis, but neuro-oncology centers with active clinical trial programs are seeing a small but increasing cadre of patients with longer survival. Molecularly targeted therapeutics, personalized therapy based on molecular profiling of individual tumors, and immunotherapeutic strategies are all being evaluated and refined in clinical trials. Understanding of the molecular mechanisms of tumor-mediated immunosuppression, and specifically interactions between tumor cells and immune effector cells in the tumor microenvironment, has led to a new generation of immunotherapies, including vaccine and immunomodulatory strategies as well as T-cell-based treatments. Molecularly targeted therapies, chemoradiation, immunotherapies, and anti-angiogenic therapies have created the need to develop more reliable neuroimaging criteria for differentiating the effects of therapy from tumor progression and changes in blood–brain barrier physiology from treatment response. Translational clinical trials for patients with GBM now incorporate quantitative imaging using both magnetic resonance imaging and positron emission tomography techniques. This update presents a summary of the current standards for therapy for newly diagnosed and recurrent GBM and highlights promising translational research.