Radiotherapy plus concurrent or sequential temozolomide for glioblastoma in the elderly: a meta-analysis

Management of glioblastoma in elderly patients: A review of the literature

High grade gliomas are the most common primary aggressive brain tumours with a very poor prognosis and a median survival of less than 2 years. The standard management protocol of newly diagnosed glioblastoma patients involves surgery followed by radiotherapy, chemotherapy in the form of temozolomide and further adjuvant temozolomide. The recent advances in molecular profiling of high-grade gliomas have further enhanced our understanding of the disease. Although the management of glioblastoma is standardised in newly diagnosed adult patients there is a lot of debate regarding the best treatment approach for the newly diagnosed elderly glioblastoma patients. In this review article we attempt to summarise the findings regarding surgery, radiotherapy, chemotherapy, and their combination in order to offer the best possible management modality for this group of patients. Elderly patients 65-70 with an excellent functional level could be considered as candidates for the standards treatment consisting of surgery, standard radiotherapy with concomitant and adjuvant temozolomide. Similarly, elderly patients above 70 with good functional status could receive the above with the exception of receiving a shorter course of radiotherapy instead of standard. In elderly GBM patients with poorer functional status and MGMT promoter methylation temozolomide chemotherapy can be considered. For elderly patients who cannot tolerate chemotherapy, hypofractionated radiotherapy is an option. In contrast to the younger adult patients, it seems that a careful individualised approach is a key element in deciding the best treatment options for this group of patients.

Genome-wide DNA methylation analysis identifies potent CpG signature for temzolomide response in non-G-CIMP glioblastomas with unmethylated MGMT promoter: MGMT-dependent roles of GPR81

PURPOSES

To identify potent DNA methylation candidates that could predict response to temozolomide (TMZ) in glioblastomas (GBMs) that do not have glioma-CpGs island methylator phenotype (G-CIMP) but have an unmethylated promoter of O-6-methylguanine-DNA methyltransferase (unMGMT).

METHODS

The discovery-validation approach was planned incorporating a series of G-CIMP-/unMGMT GBM cohorts with DNA methylation microarray data and clinical information, to construct multi-CpG prediction models. Different bioinformatic and experimental analyses were performed for biological exploration.

RESULTS

By analyzing discovery sets with radiotherapy (RT) plus TMZ versus RT alone, we identified a panel of 64 TMZ efficacy-related CpGs, from which a 10-CpG risk signature was further constructed. Both the 64-CpG panel and the 10-CpG risk signature were validated showing significant correlations with overall survival of G-CIMP-/unMGMT GBMs when treated with RT/TMZ, rather than RT alone. The 10-CpG risk signature was further observed for aiding TMZ choice by distinguishing differential outcomes to RT/TMZ versus RT within each risk subgroup. Functional studies on GPR81, the gene harboring one of the 10 CpGs, indicated its distinct impacts on TMZ resistance in GBM cells, which may be dependent on the status of MGMT expression.

CONCLUSIONS

The 64 TMZ efficacy-related CpGs and in particular the 10-CpG risk signature may serve as promising predictive biomarker candidates for guiding optimal usage of TMZ in G-CIMP-/unMGMT GBMs.

Potent predictive CpG signature for temozolomide response in non-glioma-CpG island methylator phenotype glioblastomas with methylated MGMT promoter

Aim: We aimed to identify potent CpG signatures predicting temozolomide (TMZ) response in glioblastomas (GBMs) that do not have the glioma-CpG island methylator phenotype (G-CIMP) but have a methylated promoter of MGMT (me MGMT). Materials & methods: Different datasets of non-G-CIMP me MGMT GBMs with molecular and clinical data were analyzed. Results: A panel of 77 TMZ efficacy-related CpGs and a seven-CpG risk signature were identified and validated for distinguishing differential outcomes to radiotherapy plus TMZ versus radiotherapy alone in non-G-CIMP me MGMT GBMs. An integrated classification scheme was also proposed for refining a MGMT-based TMZ-guiding approach in all G-CIMP-GBMs. Conclusion: The CpG signatures may serve as promising predictive biomarker candidates for guiding optimal TMZ usage in non-G-CIMP me MGMT GBMs.

A Novel Pseudogene Methylation Signature to Predict Temozolomide Outcome in Non-G-CIMP Glioblastomas

Objective

Alterations in the methylation state of pseudogenes may serve as clinically useful biomarkers of glioblastomas (GBMs) that do not have glioma-CpG island methylator phenotype (G-CIMP).

Methods

Non-G-CIMP GBM datasets were included for evaluation, and a RISK-score signature was determined from the methylation state of pseudogene loci. Both bioinformatic and experimental analyses were performed for biological validation.

Results

By integrating clinical information with DNA methylation microarray data, we screened a panel of eight CpGs from discovery cohorts of non-G-CIMP GBMs. Each CpG could accurately and independently predict the prognosis of patients under a treatment regime that combined radiotherapy (RT) and temozolomide (TMZ). The 8-CpG signature appeared to show opposite prognostic correlations between patients treated with RT/TMZ and those treated with RT monotherapy. The analyses further indicated that this signature had predictive value for TMZ efficacy because different survival benefits between RT/TMZ and RT therapies were observed in each risk subgroup. The incorporation of other risk factors, such as age and O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status, with our pseudogene methylation signature could provide precise risk classification. In vitro experimental data revealed that two locus-specific pseudogenes (ZNF767P and CLEC4GP1) may modulate TMZ resistance via distinct mechanisms in GBM cells.

Conclusion

The biologically and clinically relevant RISK-score signature, based on pseudogene methylation loci, may offer information for predicting TMZ responses of non-G-CIMP GBMs, that is independent from, but complementary to, MGMT-based approaches.

Surgical strategies for older patients with glioblastoma

Objective

While adjuvant treatment regimens have been modified for older patients with glioblastoma (GBM), surgical strategies have not been tailored.

Methods

Clinical data of 48 consecutive patients aged 70 years or older, who underwent surgical resection for GBM with intraoperative ultrasonography (IoUS) alone or combination with intraoperative MRI (IoMRI) at Yale New Haven Hospital were retrospectively reviewed. Variables were analyzed, and comparative analyses were performed.

Results

The addition of IoMRI was not superior to IoUS alone in terms of overall survival (OS) (P = 0.306), Karnofsky Performance Score (KPS) at postoperative 6 weeks (P = 0.704) or extent of resection (P = 0.263). Length of surgery (LOSx), however, was significantly longer (P = 0.0002) in the IoMRI group. LOSx (P = 0.015) and hospital stay (P = 0.025) were predictors of postoperative complications. Increased EOR (GTR or NTR) (P = 0.030), postoperative adjuvant treatment (P < 0.0001) and postoperative complications (P = 0.006) were predictive for OS. Patients with relatively lower preoperative KPS scores (<70) showed significant improvement at postoperative 6 weeks (P<0.0001). Patients with complications (P = 0.038) were more likely to have lower KPS at postoperative 6 weeks.

Conclusions

Aggressive management with surgical resection should be considered in older patients with GBM, even those with relatively poor KPS. The use of ioMRI in this population does not appear to confer any measurable benefit over ioUS in experienced hands, but prolongs the length of surgery significantly, which is a preventable prognostic factor for impeding care.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-021-03862-z.

Exosomal noncoding RNAs: key players in glioblastoma drug resistance

Glioma, as one of the most severe human malignancies, is defined as the Central Nervous System's (CNS) tumors. Glioblastoma (GBM) in this regard, is the most malignant type of gliomas. There are multiple therapeutic strategies to cure GBM, for which chemotherapy is often the first-line treatment. Still, various cellular processes, such as uncontrolled proliferation, invasion and metastasis, may disturb the treatment efficacy. Drug resistance is another process in this way, which can also cause undesirable effects. Thereupon, identifying the mechanisms, involved in developing drug resistance and the relevant mechanisms can be very helpful in GBM management. The discovery of exosomal non-coding RNAs (ncRNAs), RNA molecules that can be transferred between the cells and different tissues using the exosomes, was a milestone in this regard. It has been revealed that the key exosomal ncRNAs, including circular RNAs, microRNAs, and long ncRNAs, are able to modulate GBM drug resistance through different signaling pathways or by affecting regulatory proteins and their corresponding genes. Nowadays, researchers are trying to overcome the limitations of chemotherapy by targeting these RNA molecules. Accordingly, this review aims to clarify the substantial roles of exosomal ncRNAs in GBM drug resistance and involved mechanisms.

Integrative analysis identifies an immune-relevant epigenetic signature for prognostication of non-G-CIMP glioblastomas

The clinical and molecular implications of DNA methylation alterations remain unclear among the majority of glioblastomas (GBMs) without glioma-CpGs island methylator phenotype (G-CIMP); integrative multi-level molecular profiling may provide useful information. Independent cohorts of non-G-CIMP GBMs or IDH wild type (wt) lower-grade gliomas (LGGs) from local and public databases with DNA methylation and gene expression microarray data were included for discovery and validation of a multimarker signature, combined using a RISK score model. Bioinformatic and in vitro functional analyses were employed for biological validation. Using a strict multistep selection approach, we identified eight CpGs, each of which was significantly correlated with overall survival (OS) of non-G-CIMP GBMs, independent of age, the O-6-methylguanine-DNA methyltransferase (MGMT) methylation status, treatments and other identified CpGs. An epigenetic RISK signature of the 8 CpGs was developed and validated to robustly and independently prognosticate prognosis in different cohorts of not only non-G-GIMP GBMs, but also IDHwt LGGs. It also showed good discriminating value in stratified cohorts by current clinical and molecular factors. Bioinformatic analysis revealed consistent correlation of the epigenetic signature to distinct immune-relevant transcriptional profiles of GBM bulks. Functional experiments showed that S100A2 appeared to be epigenetically regulated by one identified CpG and was associated with GBM cell proliferation, apoptosis, invasion, migration and immunosuppression. The prognostic 8-CpGs RISK score signature may be of promising value for refining current glioma risk classification, and its potential links to distinct immune phenotypes make it a promising biomarker candidate for predicting response to anti-glioma immunotherapy.

Hypofractionated radiation therapy with temozolomide versus standard chemoradiation in patients with glioblastoma multiforme (GBM): A prospective, single institution experience

BACKGROUND AND AIM

the study aimed to determine whether hypofractionated radiotherapy (HFRT) with simultaneous and adjuvant temozolomide (TMZ) was feasible and could provide adequate disease control in primary GBM patients with poor prognostic factors including large tumor size, poor performance status, unresectable or multifocal lesions, poor imaging and inflammatory indices.

PATIENTS AND METHODS

A total of 93 patients with glioblastoma multiforme were collected and distributed randomly as 1:1.7 of cases to controls; cases or arm (I) received HFRT with 45 Gy in 15 fractions over 3 weeks concurrently with TMZ. Controls or arm (II) received standard conventional fractionation radiotherapy of 60 Gy in 30 fractions over 6 weeks concurrently with TMZ.

RESULTS

35 patients were recruited in arm I while 58 patients in arm II with significant difference in site of GBM, pattern of enhancement, type of surgery, and neutrophil to lymphocyte ratio, while no significant differences in tumor size, focality, responses, progression free survival, and overall survival (OS), only the type of surgery was an independent predictor for OS, no significant difference in the type and degree of toxicity between both arms.

CONCLUSION

Our results showed that HFRT with concurrent TMZ is a feasible therapeutic approach in patients with GBM, especially those with poor prognostic factors, assuring high treatment compliance and low toxicity rates. Dose escalation and reduction in overall treatment time are clear advantages of HFRT, while at least the same survival rates as conventional fractionated RT are maintained.

Guiding Treatment Choices for Elderly Patients with Glioblastoma by a Comprehensive Geriatric Assessment

PURPOSE OF REVIEW

The incidence of glioblastoma multiforme (GBM) increases with age; more than half of newly diagnosed patients are older than 65 years. Due to age-dependent decreasing organ functions, comorbidities, functional decline, and increasing risk of social isolation, not all patients are able to tolerate standard therapy of GBM with 6 weeks of radiochemotherapy.

RECENT FINDINGS

A set of alleviated therapies, e.g., chemotherapy or radiotherapy alone, hypofractionated radiotherapies with different total doses and variable fractionation regimens as well as hypofractionated radiotherapy with concomitant and adjuvant chemotherapy, have been evaluated during the last years. However, clinicians are still unsure which therapy would fit best to a given patient. Recently, the predictive value of comprehensive geriatric assessment regarding tolerance of chemotherapy and prediction of early mortality has been validated for older GBM patients in a retrospective trial. Thus, it appears that neuro-oncology is now ready for the prospective implementation of geriatric assessment to guide treatment planning for elderly GBM patients.

Interaction Between Near-Infrared Radiation and Temozolomide in a Glioblastoma Multiform Cell Line: A Treatment Strategy?

Photodynamic therapy (PDT) is a potential therapeutic modality against cancer, resulting from the interaction of a photosensitizer (PS) and radiation that generates damage to tumor cells. The use of near-infrared radiation (IR-A) is relevant because presents recognized biological effects, such as antioxidant, neuroprotective and antitumor effects. Glioblastoma is the most aggressive central nervous system (CNS) neoplasm with high proliferation and tissue invasion capacity and is resistant to radio and chemotherapy. Here, we evaluated in vitro the possible interaction of temozolomide (TMZ) with IR-A in a glioblastoma cell line (C6) and in a human keratinocyte cell line (HaCat) how non-tumor cell model, in an attempt to search for a new treatment strategy. The effects of TMZ, IR-A and the interaction between TMZ and IR-A was evaluated by viability exclusion with trypan blue. To perform the interaction experiments, we have chosen 10 μM TMZ and 4.5 J/cm² of IR-A. From this, we evaluated cytotoxicity, cell proliferation, intracellular reactive oxygen species levels (ROS), as well as the process of cell migration and the P-gp and MRP-1 activity. Cell death mainly due to apoptosis, followed by necrosis, decreased cell proliferation, increased ROS levels, decreased cell migration and decreased P-gp and MRP1 activity were observed only when there was interaction between TMZ and IR-A in the C6 cell line. The interaction between TMZ and IR-A was not able to affect cell proliferation in the HaCat non-tumor cell line. Our results suggest that this interaction could be a promising approach and that in the future may serve as an antitumor strategy for PDT application.

Optimal adjuvant therapy in elderly glioblastoma: results from a systematic review and network meta-analysis

BACKGROUND

There exists lack of consensus worldwide regarding the most optimal adjuvant therapy regimen in elderly patients with newly-diagnosed glioblastoma (GBM).

PURPOSE

To identify the most optimal adjuvant therapy regimen in elderly GBM patients through systematic review and network meta-analysis.

METHODS

Prospective trials randomly assigning elderly GBM patients post-operatively to any adjuvant therapy regimen were included. The primary outcome measure was overall survival. Numbers of events, patients at-risk, and censored patients for survival were estimated from Kaplan-Meier survival curves in the interval of 0-12 months. The total person-time at risk and the mortality × 100 person-months was also estimated. The relative ranking probability of each treatment and rankograms were used to estimate the hierarchy of each intervention in terms of overall survival. The mean rank values and the surface under the cumulative ranking (SUCRA) curves were also calculated.

RESULTS

A systematic literature search identified 1278 abstracts, that were screened to retrieve full-text manuscripts of potentially eligible articles. After detailed assessment, data from 1569 patients in 7 randomized controlled trials (RCTs) treated with one of following regimens was extracted and analyzed: normofractionated radiotherapy (RT) delivered over 5.5-6 weeks; moderately hypofractionated RT (2-3 weeks) either alone or in combination with temozolomide or bevacizumab; extremely hypofractionated RT (1-week); temozolomide monotherapy; and best supportive care alone. In terms of overall survival, moderately hypofractionated RT (3-weeks) with concurrent and adjuvant temozolomide emerged as the best and second-best adjuvant therapy option with 81% probability and 99.1% probability respectively. Using SUCRA, the surface area for moderately hypofractionated RT (3-weeks) with concurrent and adjuvant temozolomide reached almost 100%, confirming it as the best intervention. As expected, best supportive care alone was ranked as the worst treatment strategy.

CONCLUSION

Moderately hypofractionated RT (3-weeks) with concurrent and adjuvant temozolomide is the most optimal and preferred adjuvant therapeutic regimen in elderly GBM.

Novel predictive epigenetic signature for temozolomide in non-G-CIMP glioblastomas

Objective

To identify novel epigenetic signatures that could provide predictive information that is complementary to promoter methylation status of the O-6-methylguanine-DNA methyltransferase (MGMT) gene for predicting temozolomide (TMZ) response, among glioblastomas (GBMs) without glioma-CpGs island methylator phenotype (G-CIMP)

Methods

Different cohorts of primary non-G-CIMP GBMs with genome-wide DNA methylation microarray data were included for discovery and validation of a multimarker signature, combined using a RISK score model. Different statistical analyses and functional experiments were performed for clinical and biological validation.

Results

By employing discovery cohorts with radiotherapy (RT) and TMZ versus RT alone and a strict multistep selection strategy, we identified seven CpGs, each of which was significantly correlated with overall survival (OS) of non-G-CIMP GBMs with RT/TMZ, independent of age, MGMT promoter methylation status, and other identified CpGs. A RISK score signature of the 7 CpGs was developed and validated to distinguish non-G-CIMP GBMs with differential survival outcomes to RT/TMZ, but not to RT alone. The interaction analyses also showed differential outcomes to RT/TMZ versus RT alone within the RISK score-based subgroups. The signature could also improve the risk classification by age and MGMT promoter methylation status. Functional experiments showed that HSBP2 appeared to be epigenetically regulated by one identified CpG and was associated with TMZ resistance, but it was not associated with cell proliferation or apoptosis in GBM cell lines. The predictive value of the single CpG methylation of HSBP2 by pyrosequencing was observed in a local cohort of isocitrate dehydrogenase 1 (IDH1) ^R132H wild-type GBMs.

Conclusions

This novel epigenetic signature might be a promising predictive (but not a general prognostic) biomarker and be helpful for refining the MGMT-based guiding approach to TMZ usage in non-G-CIMP GBMs.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0670-9) contains supplementary material, which is available to authorized users.

The Clinical Significance of O6-Methylguanine-DNA Methyltransferase Promoter Methylation Status in Adult Patients With Glioblastoma: A Meta-analysis

Background and objective

Promoter status of O⁶-methylguanine-DNA methyltransferase (MGMT) has been widely established as a clinically relevant factor in glioblastoma (GBM) patients. However, in addition to varied therapy schedule, the prognosis of GBM patients is also affected by variations of age, race, primary or recurrent tumor. This study comprehensively investigated the association between MGMT promoter status and prognosis in overall GBM patients and in different GBM subtype including new diagnosed patients, recurrent patients and elderly patients.

Methods

A comprehensive search was performed using PubMed, EMBASE, Cochrane databases to identify literatures (published from January 1, 2005 to April 1, 2017) that evaluated the associations between MGMT promoter methylation and prognosis of GBM patients.

Results

Totally, 66 studies including 7,886 patients met the inclusion criteria. Overall GBM patients with a methylated status of MGMT receiving temozolomide (TMZ)-containing treatment had better overall survival (OS) and progression-free survival (PFS) [OS: hazard ratio (HR) = 0.46, 95% confidence interval (CI): 0.41–0.52, p < 0.001, Bon = 0.017; PFS: HR = 0.48, 95% CI 0.40–0.57, p < 0.001, Bon = 0.014], but no significant advantage on OS or PFS in GBM patients with TMZ-free treatment was observed (OS: HR = 0.97, 95% CI 0.91–1.03, p = 0.08, Bon = 1; PFS: HR = 0.76, 95% CI 0.57–1.02, p = 0.068, Bon = 0.748). These different impacts of MGMT status on OS were similar in newly diagnosed GBM patients, elderly GBM patients and recurrent GBM. Among patients receiving TMZ-free treatment, survival benefit in Asian patients was not observed anymore after Bonferroni correction (Asian OS: HR = 0.78, 95% CI 0.64–0.95, p = 0.02, Bon = 0.24, I² = 0%; PFS: HR = 0.69, 95% CI 0.50–0.94, p = 0.02, Bon = 0.24). No benefit was observed in Caucasian receiving TMZ-free therapy regardless of Bonferroni adjustment.

Conclusion

The meta-analysis highlights the universal predictive value of MGMT methylation in newly diagnosed GBM patients, elderly GBM patients and recurrent GBM patients. For elderly methylated GBM patients, TMZ alone therapy might be a more suitable option than radiotherapy alone therapy. Future clinical trials should be designed in order to optimize therapeutics in different GBM subpopulation.

Management of elderly patients with glioblastoma-multiforme-a systematic review

The management of elderly patients with glioblastoma-multiforme (GBM) remains poorly defined with many experts in the past advocating best supportive care, in view of limited evidence on efficacy of more aggressive treatment protocols. There is randomised evidence (NORDIC and NA-O8 studies) to support the use of surgery followed by adjuvant monotherapy with either radiotherapy (RT) using hypofractionated regimes (e.g. 36 Gy in 6 fractions OR 40 Gy in 15 fractions) or chemotherapy with temozolomide (TMZ) in patients expressing methylation of promoter for O⁶-methylguanine-DNA methyltransferase enzyme. However, the role of combined-modality therapy involving the use of combined RT and TMZ protocols has remained controversial with data from the EORTC (European Organisation for Research and Treatment of Cancer)-NCIC (National Cancer Institute of Canada) studies indicating that patients more than 65 years of age may not benefit significantly from combining standard RT fractionation using 60 Gy in 30 fractions with concurrent and adjuvant TMZ. More recently, randomised data has emerged on combining hypofractionated RT with concurrent and adjuvant TMZ. We provide a comprehensive review of literature with the aim of defining an evidence-based algorithm for management of elderly glioblastoma-multiforme population.

Glioblastoma Treatment in the Elderly

Although current treatment advances prolong patient survival, treatment for glioblastoma (GBM) in the elderly has become an emerging issue. The definition of "elderly" differs across articles; GBM predominantly occurs at an age ≥65 years, and the prognosis worsens with increasing age. Regarding molecular markers, isocitrate dehydrogenase (IDH) mutations are less common in the elderly with GBM. Meanwhile, O6-methylguanine DNA methyltransferase (MGMT) promoter methylation has been identified in approximately half of patients with GBM. Surgery should be considered as the first-line treatment even for elderly patients, and maximum safe resection is recommended if feasible. Concurrently, radiotherapy is the standard adjuvant therapy. Hypofractionated radiotherapy (e.g., 40 Gy/15 Fr) is suitable for elderly patients. Studies also supported the concurrent use of temozolomide (TMZ) with radiotherapy. In cases wherein elderly patients cannot tolerate chemoradiation, TMZ monotherapy is an effective option when MGMT promoter methylation is verified. Conversely, tumors with MGMT unmethylated promoter may be treated with radiotherapy alone to reduce the possible toxicity of TMZ. Meanwhile, the efficacy of bevacizumab (BEV) in elderly patients remains unclear. Similarly, further studies on the efficacy of carmustine wafers are needed. Based on current knowledge, we propose a treatment diagram for GBM in the elderly.

A comparison between oral chemotherapy combined with radiotherapy and radiotherapy for newly diagnosed glioblastoma: A systematic review and meta-analysis

The prognosis of glioblastoma (GBM), a major subtype of grade IV glioma, is rather poor nowadays. The efficiency of chemotherapy serving as the adjunct to radiotherapy (RT) for treating GBM is still controversial. In this study, we aim to investigate the overall survival (OS) and progression-free survival (PFS) in patients with newly diagnosed GBM received RT plus chemotherapy or with RT alone.Literatures were searched from the PubMed, Embase, and Cochrane Library between January 2001 and June 2015. Study selection was conducted based on the following criteria: randomized clinical trial (RCT) of adjuvant RT plus chemotherapy versus RT alone; studies comparing OS and/or PFS; and studies including cases medically confirmed of newly diagnosed GBM.Five RCTs (1655 patients) were eligible in this study. The meta-analysis showed a significant improvement in OS of patients treated with RT plus oral chemotherapy compared with that of RT alone (hazard ratio 0.70; 95% confidence interval, 0.56-0.88, P = .002).Adjuvant chemotherapy confers a survival benefit in patients newly diagnosed with GBM.

Management of glioblastoma in elderly patients

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults over 55years of age. The median age of diagnosis for patients with GBM is 64years old, with the incidence of patients between 75 and 85 increasing. The optimal treatment paradigm for elderly GBM patients continues to evolve due to the higher frequency of age-related and/or medical co-morbidities. Geriatric GBM patients have historically been excluded from larger, controlled clinical trials due to their presumed decreased likelihood of a sustained treatment response and/or a prolonged good outcome. Here, we highlight current treatment considerations of elderly GBM patients with respect to surgical, radiotherapeutic and systemic modalities, with considerations for improving future clinical outcomes for this patient population.

Pattern of care and outcome in elderly patients with glioblastoma: Data in 151 patients from 3 Lombardia Hospitals

The appropriate treatment approach for elderly patients with glioblastoma multiforme (GBM) is unclear, although different studies suggest survival benefit in fit patients treated with radiotherapy and chemiotherapy after surgery. We performed a retrospective analysis of 151 patients older than 65years with GBM treated in 3 Lombardia Hospitals. In univariate regression analysis higher KPS (p=0.02), macroscopical total resection (p<0.003), radiotherapy (p<0.0001), chemotherapy (p<0.0001) and second line chemotheraphy (p=0.02) were of positive prognostic value. On the contrary older age (>70years), presence of seizure at onset and additional resection after tumor recurrence did not influence OS. Multivariate analysis revealed radiotherapy (HR 0.2 p<0.0001) and extent of surgery (HR 0.3, p=0,0063) as positive independent prognostic factors. Patients receiving radio-chemiotherapy displayed more treatment-related toxicities with a slightly prolonged OS versus those receiving hypofractionated radiotherapy. With the limits of a retrospective study, our data suggest that in elderly fit patients extensive surgery should be considered, moreover adjuvant treatments led to an increase in OS. Randomized controlled study are needed to develop treatment guidelines for elderly GBM patients and to assess whether the combination of post-surgical radio and chemiotherapy may be superior to hypofractionated radiotherapy and chemiotherapy in fit patients.

Knockdown of Angiopoietin-Like Protein 2 Inhibits Proliferation and Invasion in Glioma Cells via Suppressing the ERK/MAPK Signaling Pathway

Angiopoietin-like protein 2 (ANGPTL2), a member of the glycoprotein family, is mainly secreted by adipose tissues under normal conditions. Recently, ANGPTL2 has been found to be upregulated in some types of cancers and is considered to be a tumor promoter. However, the functional significance of ANGPTL2 in glioma has not yet been elucidated. In this study, we investigated the specific role of ANGPTL2 in glioma. The results showed that ANGPTL2 was highly expressed in glioma tissues and cell lines. Knockdown of ANGPTL2 reduced the proliferative and invasive abilities of glioma cells. Moreover, the tumorigenesis assay showed that ANGPTL2 knockdown inhibited glioma tumor growth in vivo. We also found that ANGPTL2 knockdown decreased the protein levels of p-ERK1/2 in glioma cells and thus blocked the activity of the ERK/MAPK signaling pathway. Taken together, our study provided the first evidence that ANGPTL2 played an oncogenic role in glioma development and might be considered as a new therapeutic target for glioma treatment.

Temozolomide with or without Radiotherapy in Patients with Newly Diagnosed Glioblastoma Multiforme: A Meta-Analysis

BACKGROUND/AIM

The current meta-analysis evaluated the survival outcomes of newly diagnosed glioblastoma patients treated with radiotherapy (RT) alone and with RT + temozolomide (TMZ).

METHODS

Relevant studies were identified by an extensive literature search in Medline, Current Contents and Cochrane databases by 2 independent reviewers using the terms "glioblastoma multiforme/glioblastoma, TMZ, radiation therapy/RT and survival."

RESULTS

Results revealed a median survival of 13.41-19 months in the combined treatment group, as opposed to 7.7-17.1 months in the RT-alone group. Progression-free survival (PFS) was also significantly different between the 2 groups (RT + TMZ, 6.3-13 months; RT-alone, 5-7.6 months). While there was no significant difference in the 6-month survival and 6-month PFS rates between the RT + TMZ and RT groups (pooled OR 0.690; p = 0.057 and OR 0.429, p = 0.052, respectively), the 1-year survival and 1-year PFS rates showed significant difference (OR 0.469; p = 0.030 and OR 0.245, p < 0.001, respectively).

CONCLUSIONS

Concomitant RT + TMZ is more effective and improves the overall survival and PFS in patients with newly diagnosed glioblastoma.

Impact of concurrent chemotherapy with radiation therapy for elderly patients with newly diagnosed glioblastoma: a review of the National Cancer Data Base

To investigate the utilization and overall survival (OS) impact of concurrent chemotherapy in combination with radiation therapy (RT) for elderly glioblastoma (GBM) patients. Elderly patients (age >70) with supratentorial and nonmetastatic GBM who received RT of 20-75 Gy with concurrent single-agent chemotherapy (ChemoRT) or without (RT alone) during 2004-2012 were identified from the National Cancer Data Base (NCDB). The Cochran-Armitage test was used for trend analysis. Hazard ratios (HR) and 95% confidence intervals (CIs) were determined using Cox proportional hazards. Propensity score analysis was performed to reduce selection bias in treatment allocation. A total of 5252 patients were identified (RT alone: n = 1389; ChemoRT: n = 3863). There was increasing utilization of chemotherapy during this period (45-80%, P < .001). A similar trend was also observed for the subset of age >80 (25-68%, P < .001). ChemoRT was associated with significantly better OS than RT alone (HR 0.79, 95% CI 0.70-0.89, P < .001) on multivariate analysis, and similar OS benefit was demonstrated with 1202 pairs of propensity-matched patients (HR 0.79, 95% CI 0.73-0.86, P < .001). For the matched pair, the median OS was 5.8 months with ChemoRT and 5.0 months with RT alone; the 2-year OS rate was 9% with ChemoRT and 4% with RT alone (P < .001). Concurrent chemotherapy has been administered with RT for the majority of elderly GBM patients. Addition of chemotherapy to RT for elderly GBM patients is associated with significantly improve OS in routine clinical practice.

Analysis of Treatment Tolerance and Factors Associated with Overall Survival in Elderly Patients with Glioblastoma

BACKGROUND

As the population ages, the proportion of elderly patients with glioblastomas has increased. Recently, many researchers have focused on the treatments available to and prognoses in elderly patients with glioblastomas.

METHODS

We conducted a retrospective study of glioblastoma patients aged 60 years old or older who were treated at the Neurosurgery Center at Beijing Tiantan Hospital from 2012 to 2014. Their clinical features, immunohistochemical characteristics, treatments, and outcomes were evaluated to determine treatment tolerance and identify prognostic factors.

RESULTS

Among the 70 included patients, the median survival time was 15 months. In the univariate analysis, patients who underwent a gross total resection had longer overall survival times than patients who had a subtotal resection (P < 0.05), and patients who received postoperative adjuvant therapy had longer overall survival times than those with no postoperative adjuvant therapy (P < 0.05). The expression of the p53 protein significantly affected overall survival. Patients with low p53 protein expression had a median survival of 17 months, whereas those who had high p53 protein expression had a median survival of 11.50 months (P < 0.05). Undergoing a gross total resection, receiving postoperative adjuvant therapy and having low p53 protein expression were factors that independently contributed to longer overall survival times in multivariate analysis.

CONCLUSIONS

Maximal safe surgical resection followed by radiotherapy with concurrent and adjuvant temozolomide significantly prolonged overall survival times and was well tolerated in elderly patients with glioblastomas. In addition, low p53 protein expression was a significant favorable prognostic indicator in this population.

Histone Methylation by Temozolomide; A Classic DNA Methylating Anticancer Drug

BACKGROUND/AIM

The alkylating agent, temozolomide (TMZ), is considered the standard-of-care for high-grade astrocytomas -known as glioblastoma multiforme (GBM)- an aggressive type of tumor with poor prognosis. The therapeutic benefit of TMZ is attributed to formation of DNA adducts involving the methylation of purine bases in DNA. We investigated the effects of TMZ on arginine and lysine amino acids, histone H3 peptides and histone H3 proteins.

MATERIALS AND METHODS

Chemical modification of amino acids, histone H3 peptide and protein by TMZ was performed in phosphate buffer at physiological pH. The reaction products were examined by mass spectrometry and western blot analysis.

RESULTS

Our results showed that TMZ following conversion to a methylating cation, can methylate histone H3 peptide and histone H3 protein, suggesting that TMZ exerts its anticancer activity not only through its interaction with DNA, but also through alterations of protein post-translational modifications.

CONCLUSION

The possibility that TMZ can methylate histones involved with epigenetic regulation of protein indicates a potentially unique mechanism of action. The study will contribute to the understanding the anticancer activity of TMZ in order to develop novel targeted molecular strategies to advance the cancer treatment.

Diagnosis and New Treatment Modalities for Glioblastoma: Do They Improve Patient Survival?

Central nervous system (CNS) malignances include tumors of the brain and spinal cord. Taking into account the cell type where they originate from, there are almost 120 different types of CNS tumors. Benign tumors are not aggressive and normally do not invade other organs; however, they require surgical removal before they alter the surrounding brain functions. Primary malignant brain tumors commonly include astrocytomas, oligodendrogliomas, and ependimomas, where astrocytomas represent around 76%. The World Health Organization (WHO) has defined four histological grades of astrocytomas that range from the less aggressive tumors (grade I) to highly malignant tumors (grade IV). These grade IV tumors, also called glioblastoma (GBM), are the most aggressive of the primary malignant brain tumors. Patients with GBM have a median survival of 12 to 15 months. Current treatment for GBM includes surgery, radiotherapy and chemotherapy. Although there have been some advances in diagnosis and treatment, there is still no optimal treatment available for GBMs. In this review, we will discuss the approaches for GBM diagnosis and treatment, with a special emphasis to post-treatment imaging, and whether novel targeted therapies have impacted the survival of GBM patients. In addition, we will discuss clinical trials and the future of GBM diagnosis and treatment.

MiR-27a regulates Wnt/beta-catenin signaling through targeting SFRP1 in glioma

Glioma is one of the most common intracranial tumors, and the prognosis is poor, although more and more treatments are employed. Wnt/beta-catenin signaling has been reported to be associated with glioma. SFRP1 acts as an antagonist and inhibits Wnt signaling by binding to Wnt molecules. In the present study, we aimed to investigate miRNA-27a as an antineoplastic factor that inhibits the Wnt/beta-catenin pathway by binding to the SFRP1 3'-UTR in glioma in vitro. We first showed that the expression of miR-27a was elevated in both glioma samples and cell lines. Furthermore, downregulation of miR-27a induced growth inhibition, cycle arrest, and apoptosis, and suppressed invasion/migration in glioma cell lines. Quantitative real-time PCR, western blot, and luciferase assay analysis showed that SFRP1 is a direct target of miR-27a. Overexpression of SFRP1 inhibited the malignancy of glioma cell lines. Our investigation showed that downregulation of miR-27a suppressed beta-catenin/TCF-4 transcription activity by targeting SFRP1. Our findings identify a role for miR-27a in glioma cell viability, cycle, apoptosis, and invasion/migration after activation of Wnt/beta-catenin signaling through SFRP1.

The evolving roles and controversies of radiotherapy in the treatment of glioblastoma

Numerous randomised controlled trials have demonstrated the benefit of radiation therapy in patients with newly diagnosed glioblastoma and it has been the cornerstone of treatment for decades. The aims of this review are to (1) Briefly outline the historical studies which resulted in radiation being the current standard of care as used in the Stupp et al. trial (2) Discuss the evolving role of radiation therapy in the management of elderly patients (3) Review the current evidence and ongoing studies of radiation use in the recurrent/salvage setting and (4) Discuss the continuing controversies of volume delineation in the planning of radiation delivery.

Hirudin inhibits cell growth via ERK/MAPK signaling in human glioma

Glioma is one of the most common intracranial tumors, and the prognosis is poor though more and more treatments are employed. ERK/MAPK signaling has been reported to be associated with glioma. In the present study, we aimed to investigate hirudin as an antineoplastic drug inhibits ERK/MAPK signaling in glioma growth in vitro. The cell proliferation and apoptosis rate were detected using MTS and Annexin V staining assay, cell cycle distribution was detected using flowcytometry assay. Furthermore, the relevant molecules of ERK/MAPK signaling were examined using Western blot analysis and immunofluorescence staining assay. We provide the first evidence that hirudin increase inactivation state of ERK1/2, down-regulate the expression of canonical ERK/MAPK signaling pathway and establish an important role for hirudin in the treatment of glioma cells.

Predictors of survival and effect of short (40 Gy) or standard-course (60 Gy) irradiation plus concomitant temozolomide in elderly patients with glioblastoma: a multicenter retrospective study of AINO (Italian Association of Neuro-Oncology)

The efficacy of temozolomide (TMZ) plus radiation therapy (RT) in elderly patients with glioblastoma is unclear. We performed a large multicenter retrospective study to analyze prognostic factors and clinical outcome in these patients. Inclusion criteria were age ≥65 years, newly histologically confirmed glioblastoma, ECOG PS 0-2, adjuvant treatment with RT plus TMZ. We enrolled 237 patients; the average age was 71 and ECOG PS was 0-1 in 196 patients; gross total resection was performed in 174 cases. MGMT was analyzed in 151 persons and was methylated in 56 %. IDH1 was assessed in 100 patients and was mutated in 6 %. Seventy-one patients were treated with RT 40 Gy and 166 with RT 60 Gy. Progression-free survival and overall survival (OS) were 11.3 and 17.3 months, respectively. Overall survival was 19.4 vs 13.8 months for patients treated with RT 60 Gy and 40 Gy (p = 0.02); OS was 17.7 versus 16.1 months for patients treated with gross total resection vs partial surgery (p = 0.02); OS was 21.2 versus 13.6 months for methylated and unmethylated MGMT (p < 0.001). On multivariate analysis, gross total resection, RT 60 Gy, methylated MGMT and ECOG PS 0-1 were independent predictors of longer survival. Twenty-five patients (10 %) had grade 3-4 haematological toxicity during the concomitant treatment. We showed that, in elderly patients in good clinical condition treated with concomitant treatment, standard-course irradiation might be more effective than short-course irradiation. Methylated MGMT remains the most important prognostic factor.

Patient and treatment factors associated with survival among adult glioblastoma patients: A USA population-based study from 2000-2010

In this study, we utilized the USA surveillance, epidemiology, and end results (SEER) database to examine factors influencing survival of glioblastoma multiforme (GBM) patients. GBM is the most common primary malignant brain tumor in adults and despite advances in treatment, prognosis remains poor. Using the SEER database, we defined a cohort of adult patients for the years 2000-2009 with confirmed GBM and minimum follow-up of 12 months. A total of 14,675 patients with GBM met the inclusion criteria. Demographic, clinical, and treatment variables were examined. Death was the primary outcome. Median survival time was 11 months. Patients had increasingly longer survival over the decade span. We found, on multivariate analysis, that significantly worse survival was associated with age >75 years, male sex, unmarried status, and non-Hispanic Caucasian race/ethnicity. Patients in the Northeast had a significantly lower risk of mortality. Patients with tumors that were non-lateralized and >3 cm fared worse. Patients who did not receive adjuvant radiation also had worse outcomes. Gross total resection imparted a survival advantage for patients compared to biopsy or partial resection. Thus, this report adds to the growing body of literature supporting the positive role of maximal resection on patient survival.

A Surveillance, Epidemiology and End Results-Medicare data analysis of elderly patients with glioblastoma multiforme: Treatment patterns, outcomes and cost

The Surveillance, Epidemiology and End Results (SEER) database was used to determine the treatment patterns, outcomes and cost of therapy in elderly patients with glioblastoma multiforme (GBM). The SEER-Medicare linked database was used to identify patients aged >66 years with GBM diagnosed between 1997 and 2009. The patients were stratified by initial treatment following diagnostic surgery (resection or biopsy) into 6 groups as follows: No treatment, standard radiation therapy (SRT) with and without concurrent temozolomide (TMZ), hypofractionated RT (HRT) with and without concurrent TMZ, or TMZ alone. The 3,759 patients identified had a median age of 74 years (range, 66-97 years). A total of ~48% of the patients received SRT without TMZ; ~10% received SRT with concurrent TMZ; ~29% received no treatment; ~10% received HRT without TMZ; ~1% received HRT with TMZ; and <1% received TMZ alone. Untreated patients had a median survival of 2 months (range, 0-89 months). Patients treated with SRT with and without concurrent TMZ had a median survival of 11 and 9 months, respectively (P=0.01). Patients treated with HRT with and without TMZ or TMZ alone had a median survivals of 3 months [adjusted hazard ratio (AHR)=0.48; 95% confidence interval (CI): 0.36-0.66], 4 months (AHR=0.55; 95% CI: 0.49-0.62) and 6 months (AHR=0.43; 95% CI: 0.29-0.62), respectively. The median post-surgery total treatment cost for patients receiving HRT with and without TMZ or TMZ alone was 63,915, 42,834 and 48,298 USD, respectively. Standard RT with concurrent TMZ was associated with improved survival, even in patients aged >75 years. HRT with and without concurrent TMZ and TMZ alone improved survival compared to the no treatment group. Therefore, in certain cases, HRT or TMZ alone may be more cost-effective, with similar survival outcomes. The various treatment options highlight the need for geriatric assessment tools to aid in therapeutic decision making.

Management of high-grade gliomas in the elderly

The incidence of glioblastoma (GBM) has been increasing over the past several decades with majority of this increase occurring in patients older than 70 years. In spite of the growing body of evidence in this area, it is still unclear as to the optimal management of elderly patients with GBM. The elderly are a heterogeneous population with a range of comorbid conditions, and functional, cognitive, and physiological changes, and ideally treatment decisions should be made in the context of a comprehensive geriatric assessment. Patients with a poor performance status or assessed as "frail" might be considered for less aggressive therapy such as hypofractionated radiotherapy or single-agent temozolomide, whereas those with a good functional status may still benefit from maximum resection followed by combined radiation and chemotherapy. Recent randomized trials suggest molecular markers such as O(6)-methylguanine-DNA-methyltransferase promoter methylation testing could help guide these decisions, particularly when considering monotherapy with temozolomide vs radiotherapy. Ongoing studies seek to clarify the role of concurrent treatment in this population. Clinical judgment and discussion with patients and families, weighing all the options, are necessary in each case. Ultimately, patients and the neuro-oncology community should be encouraged to participate in clinical trials focused specifically on caring for the elderly patient with GBM.

The clinico-oncologic outcomes of elderly patients with glioblastoma after surgical resection followed by concomitant chemo-radiotherapy

Background

There have been controversies in the treatment of elderly patients with glioblastoma. We introduce the outcome of the treatment of elderly patients with glioblastoma comparing with younger patients.

Methods

The author's hospital database was used to identify patients with histologically confirmed glioblastoma after surgery between January 2006 and December 2013. Forty-eight patients (control group) were under age 65 and 16 patients (elderly group) were aged 65 years or over at the time of surgery.

Results

The median age of the elderly group was 71 years and control group was 50 years. Mean number of medical comorbidities was 1.8 in the elderly group vs. 0.5 in the control group. The median progression free survival (PFS) was 5.6 months and the median overall survival (OS) was 19.9 months in all patients. The elderly group had a median PFS of 4.2 months vs. 8 months for the control group (log-rank test, p=0.762). Median OS was 8.2 months in the elderly group vs. 20.9 months in the control group (log-rank test, p=0.457). Major complications occurred in 5 cases (7.8%) for all patients. The ratio of completion of concomitant chemo-radiotherapy (CCRT) was 81.3% and was the same between the two groups. In multivariable analysis, extent of resection (p=0.034) and completion of CCRT (p=0.023) were statistically significant, independent prognostic factors only for PFS in all patients by Cox proportional hazards model. Age was not an independent prognostic factor. As for OS, there was no significant factor.

Conclusion

Surgical resection and CCRT were well tolerated in elderly patients with glioblastoma, and maximal safe resection followed by timely CCRT could improve clinic-oncologic outcomes.

Management of elderly patients with gliomas

The current progressive aging of the population is resulting in a continuous increase in the incidence of gliomas in elderly people, especially the most frequent subtype, glioblastoma (GBM). This sociohealth shift, known as the "silver tsunami," has prompted the neuro-oncology community to investigate the role of specific antitumor treatments, such as surgery, radiotherapy, chemotherapy, and other targeted therapies, for these traditionally undertreated patients. Advanced age, a widely recognized poor prognostic factor in both low-grade glioma (LGG) and high-grade glioma patients, should no longer be the sole reason for excluding such older patients from receiving etiologic treatments. Far from it, results from recent prospective trials conducted on elderly patients with GBM demonstrate that active management of these patients can have a positive impact on survival without impairing either cognition or quality of life. Although prospective studies specifically addressing the management of grade 2 and 3 gliomas are lacking and thus needed, the aforementioned tendency toward acknowledging a therapeutic benefit for GBM patients might also apply to the treatment of patients with LGG and anaplastic gliomas. In order to optimize such etiologic treatment in conjunction with symptomatic management, neuro-oncology multidisciplinary boards must individually consider important features such as resectability of the tumor, functional and cognitive status, associated comorbidities, and social support.

Metabolic therapy: a new paradigm for managing malignant brain cancer

Little progress has been made in the long-term management of glioblastoma multiforme (GBM), considered among the most lethal of brain cancers. Cytotoxic chemotherapy, steroids, and high-dose radiation are generally used as the standard of care for GBM. These procedures can create a tumor microenvironment rich in glucose and glutamine. Glucose and glutamine are suggested to facilitate tumor progression. Recent evidence suggests that many GBMs are infected with cytomegalovirus, which could further enhance glucose and glutamine metabolism in the tumor cells. Emerging evidence also suggests that neoplastic macrophages/microglia, arising through possible fusion hybridization, can comprise an invasive cell subpopulation within GBM. Glucose and glutamine are major fuels for myeloid cells, as well as for the more rapidly proliferating cancer stem cells. Therapies that increase inflammation and energy metabolites in the GBM microenvironment can enhance tumor progression. In contrast to current GBM therapies, metabolic therapy is designed to target the metabolic malady common to all tumor cells (aerobic fermentation), while enhancing the health and vitality of normal brain cells and the entire body. The calorie restricted ketogenic diet (KD-R) is an anti-angiogenic, anti-inflammatory and pro-apoptotic metabolic therapy that also reduces fermentable fuels in the tumor microenvironment. Metabolic therapy, as an alternative to the standard of care, has the potential to improve outcome for patients with GBM and other malignant brain cancers.

Treatment of glioblastoma in elderly patients

Although glioblastoma occurs mostly in elderly patients, there is a paucity of trials addressing patients older than 70 years of age. Age, by itself, constitutes an unfavorable prognostic factor, which is probably due to unpropitious genetic features, but also due to iatrogenic defeatism. However, many retrospective studies report a survival benefit achieved by aggressive surgical resection seeking gross total removal of contrast-enhancing tumor according to preoperative MRI. Combined radiochemotherapy with concomitant and adjuvant temozolomide has not been investigated in prospective trials. Numerous retrospective studies and a meta-analysis suggest benefit from combined treatment. Prospective randomized trials only evaluated either temozolomide or radiotherapy. Single-treatment hypofractionated radiotherapy performed superior to conventional fractionation. In patients with methylated MGMT promoter, first-line dose-dense temozolomide facilitates prolonged survival. However, there is no comparison with combined radiochemotherapy as the standard-of-care in adult patients. Comorbidity is more frequent in elderly patients, but does not correlate with preterm termination of temozolomide treatment. This review article compiles data proposing a straightforward glioblastoma treatment, irrespective of age.

Principles of surgery for malignant astrocytomas

Malignant astrocytomas constitute the most aggressive and common primary tumors of the central nervous system. The standard treatment protocol for these tumors involves maximum safe surgical resection with adjuvant chemoradiotherapy. Despite numerous advances in surgical techniques and adjuncts, as well as the ongoing renaissance in the genetic and molecular characterization of these tumors, malignant astrocytomas continue to be associated with poor prognosis, with median overall survival averaging 15 months for grade IV astrocytomas after standard-of-care treatment. In this article, the goals, principles, techniques, prognostic factors, and modern outcomes of malignant astrocytoma surgery are reviewed. Particular attention is paid to contemporary methods of neuronavigation and functional mapping, the prognostic significance of the extent of resection, surgically delivered adjunctive therapies, and future avenues of research.

Assessment and treatment relevance in elderly glioblastoma patients

Glioblastoma (GBM) is the most common malignant primary brain tumor. Its incidence continues to increase in the elderly because the older segment of the population is growing faster than any other age group. Most clinical studies exclude elderly patients, and "standards of care" do not exist for GBM patients aged >70 years. We review epidemiology, tumor biology/molecular factors, prognostic factors (clinical, imaging data, therapeutics), and their assessments as well as classic and specific endpoints plus recent and ongoing clinical trials for elderly GBM patients. This work includes perspectives and personal opinions on this topic. Although there are no standards of care for elderly GBM patients, we can hypothesize that (i) Karnofsky performance status (KPS), probably after steroid treatment, is one of the most important clinical factors for determining our oncological strategy; (ii) resection is superior to biopsy, at least in selected patients (depending on location of the tumor and associated comorbidities); (iii) specific schedules of radiotherapy yield a modest but significant improvement; (iv) temozolomide has an acceptable tolerance, even when KPS <70, and could be proposed for methylated elderly GBM patients; and (v) the addition of concomitant temozolomide to radiotherapy has not yet been validated but shows promising results in some studies, yet the optimal schedule of radiotherapy remains to be determined. In the future, specific assessments (geriatric, imaging, biology) and use of new endpoints (quality of life and toxicity measures) will aid clinicians in determining the balance of potential benefits and risks of each oncological strategy.

Treating malignant glioma in Chinese patients: update on temozolomide

Malignant glioma, ie, anaplastic astrocytoma and glioblastoma, is the most common type of primary malignant brain tumor in the People’s Republic of China, and is particularly aggressive. The median survival of patients with newly diagnosed glioblastoma is only 12–14 months despite advanced therapeutic strategies. Treatment of malignant glioma consists mainly of surgical resection followed by adjuvant radiation and chemotherapy. Temozolomide (TMZ), a second-generation oral alkylating agent, is playing an increasingly important role in the treatment of malignant glioma in Chinese patients. Since the publication of a study by Stupp et al in 2005, which used a protocol of conventional fractionated irradiation with concomitant TMZ followed by standard TMZ for six cycles, many clinical studies in the People’s Republic of China have demonstrated that such a treatment strategy has significantly improved efficacy with limited side effects for newly diagnosed glioblastoma after surgery as compared with strategies that do not contain TMZ. However, as a relatively new agent, the history and development of TMZ for malignant glioma is not well documented in Chinese patients. Multicenter, randomized controlled trials including appropriately sized patient populations investigating multiple aspects of TMZ therapy and related combination therapies are warranted in patients with malignant glioma. This review provides an update on the efficacy, mechanism of action, adverse reactions, and clinical role of TMZ in the treatment of malignant glioma in Chinese patients.

The predictive but not prognostic value of MGMT promoter methylation status in elderly glioblastoma patients: a meta-analysis

Background

The clinical implication of O6-methylguanine-DNA methyltransferase (MGMT) promoter status is ill-defined in elderly glioblastoma patients. Here we report a meta-analysis to seek valid evidence for its clinical relevance in this subpopulation.

Methods

Literature were searched and reviewed in a systematic manner using the PubMed, EMBASE and Cochrane databases. Studies investigating the association between MGMT promoter status and survival data of elderly patients (≥65 years) were eligible for inclusion.

Results

Totally 16 studies were identified, with 13 studies included in the final analyses. The aggregate proportion of MGMT promoter methylation in elderly patients was 47% (95% confidence interval [CI]: 42–52%), which was similar to the value for younger patients. The analyses showed differential effects of MGMT status on overall survival (OS) of elderly patients according to assigned treatments: methylated vs. unmethylated: (1) temozolomide (TMZ)-containing therapies: hazard ratio [HR] 0.49, 95% CI 0.41–0.58; (2) TMZ-free therapies: HR 0.97, 95% CI 0.77–1.21. More importantly, a useful predictive value was observed by an interaction analysis: TMZ-containing therapies vs. RT alone: (1) methylated tumors: HR 0.48, 95% CI 0.36–0.65; (2) unmethylated tumors: HR 1.14; 95% CI 0.90–1.44.

Conclusion

The meta-analysis reports an age-independent presence of MGMT promoter methylation. More importantly, the study encouraged routine testing of MGMT promoter status especially in elderly glioblastoma patients by indicating a direct linkage between biomarker test and individual treatment decision. Future studies are needed to justify the mandatory testing in younger patients.