Age and radiation response in glioblastoma multiforme

Overall survival prediction for high-grade glioma patients using mathematical modeling of tumor cell infiltration

PURPOSE

This study aimed at applying a mathematical framework for the prediction of high-grade gliomas (HGGs) cell invasion into normal tissues for guiding the clinical target delineation, and at investigating the possibility of using tumor infiltration maps for patient overall survival (OS) prediction.

MATERIAL & METHODS

A model describing tumor infiltration into normal tissue was applied to 93 HGG cases. Tumor infiltration maps and corresponding isocontours with different cell densities were produced. ROC curves were used to seek correlations between the patient OS and the volume encompassed by a particular isocontour. Area-Under-the-Curve (AUC) values were used to determine the isocontour having the highest predictive ability. The optimal cut-off volume, having the highest sensitivity and specificity, for each isocontour was used to divide the patients in two groups for a Kaplan-Meier survival analysis.

RESULTS

The highest AUC value was obtained for the isocontour of cell densities 1000 cells/mm3 and 2000 cells/mm3, equal to 0.77 (p < 0.05). Correlation with the GTV yielded an AUC of 0.73 (p < 0.05). The Kaplan-Meier survival analysis using the 1000 cells/mm3 isocontour and the ROC optimal cut-off volume for patient group selection rendered a hazard ratio (HR) of 2.7 (p < 0.05), while the GTV rendered a HR = 1.6 (p < 0.05).

CONCLUSION

The simulated tumor cell invasion is a stronger predictor of overall survival than the segmented GTV, indicating the importance of using mathematical models for cell invasion to assist in the definition of the target for HGG patients.

PDPN marks a subset of aggressive and radiation-resistant glioblastoma cells

Treatment-resistant glioma stem cells are thought to propagate and drive growth of malignant gliomas, but their markers and our ability to target them specifically are not well understood. We demonstrate that podoplanin (PDPN) expression is an independent prognostic marker in gliomas across multiple independent patient cohorts comprising both high- and low-grade gliomas. Knockdown of PDPN radiosensitized glioma cell lines and glioma-stem-like cells (GSCs). Clonogenic assays and xenograft experiments revealed that PDPN expression was associated with radiotherapy resistance and tumor aggressiveness. We further demonstrate that knockdown of PDPN in GSCs in vivo is sufficient to improve overall survival in an intracranial xenograft mouse model. PDPN therefore identifies a subset of aggressive, treatment-resistant glioma cells responsible for radiation resistance and may serve as a novel therapeutic target.

Lentivirus vector‑mediated genetic manipulation of oncogenic pathways induces tumor formation in rabbit brain

Translation of promising experimental therapies from rodent models to clinical success has been complicated as the novel therapies often fail in clinical trials. Existing rodent glioma models generally do not allow for preclinical evaluation of the efficiency of novel therapies in combination with surgical resection. Therefore, the aim of the present study was to develop a larger animal model utilizing lentivirus vector‑mediated oncogenic transformation in the rabbit brain. Lentiviruses carrying constitutively active AKT and H‑Ras oncogenes, and p53 small interfering (si)RNA were introduced into newborn rabbit neural stem cells (NSCs) and intracranially implanted into rabbits' brains to initiate tumor formation. In one of the ten rabbits a tumor was detected 48 days after the implantation of transduced NSCs. Histological features of the tumor mimic was similar to a benign Grade II ganglioglioma. Immunostaining demonstrated that the tissues were positive for AKT and H‑Ras. Strong expression of GFAP and Ki‑67 was also detected. Additionally, p53 expression was notably lower in the tumor area. The implantation of AKT, H‑Ras and p53 siRNA transduced NSCs for tumor induction resulted in ganglioglioma formation. Despite the low frequency of tumor formation, this preliminary data provided a proof of principle that lentivirus vectors carrying oncogenes can be used for the generation of brain tumors in rabbits. Moreover, these results offer noteworthy insights into the pathogenesis of a rare brain tumor, ganglioglioma.

Adjuvant Radiation in Older Patients With Glioblastoma: A Retrospective Single Institution Analysis

OBJECTIVES

Standard 6-week and hypofractionated 3-week courses of adjuvant radiation therapy (RT) are both options for older patients with glioblastoma (GBM), but deciding the optimal regimen can be challenging. This analysis explores clinical factors associated with selection of RT course, completion of RT, and outcomes following RT.

MATERIALS AND METHODS

This IRB-approved retrospective analysis identified patients ≥70 years old with GBM who initiated adjuvant RT at our institution between 2004 and 2016. We identified factors associated with standard or hypofractionated RT using the Cochran-Armitage trend test, estimated time-to-event endpoints using the Kaplan-Meier method, and found predictors of overall survival (OS) using Cox proportional hazards models.

RESULTS

Sixty-two patients with a median age of 74 (range 70-90) initiated adjuvant RT, with 43 (69%) receiving standard RT and 19 (31%) receiving hypofractionated RT. Selection of short-course RT was associated with older age (p = 0.04) and poor KPS (p = 0.03). Eight (13%) patients did not complete RT, primarily for hospice care due to worsening symptoms. After a median follow-up of 37 months, median OS was 12.3 months (95% CI 9.0-15.1). Increased age (p < 0.05), poor KPS (p < 0.0001), lack of MGMT methylation (p < 0.05), and lack of RT completion (p < 0.0001) were associated with worse OS on multivariate analysis. In this small cohort, GTV size and receipt of standard or hypofractionated RT were not associated with OS.

CONCLUSIONS

In this cohort of older patients with GBM, age and KPS was associated with selection of short-course or standard RT. These regimens had similar OS, though a subset of patients experienced worsening symptoms during RT and discontinued treatment. Further investigation into predictors of RT completion and survival may help guide adjuvant therapies and supportive care for older patients.

Xenograft-based, platform-independent gene signatures to predict response to alkylating chemotherapy, radiation, and combination therapy for glioblastoma

BACKGROUND

Predictive molecular biomarkers to select optimal treatment for patients with glioblastoma and other cancers are lacking. New strategies are needed when large randomized trials with correlative molecular data are not feasible.

METHODS

Gene signatures (GS) were developed from 31 orthotopic glioblastoma patient-derived xenografts (PDXs), treated with standard therapies, to predict benefit from radiotherapy (RT-GS), temozolomide (Chemo-GS), or the combination (ChemoRT-GS). Independent validation was performed in a heterogeneously treated clinical cohort of 502 glioblastoma patients with overall survival as the primary endpoint. Multivariate Cox analysis was used to adjust for confounding variables and evaluate interactions between signatures and treatment.

RESULTS

PDX models recapitulated the clinical heterogeneity of glioblastoma patients. RT-GS, Chemo-GS, and ChemoRT-GS were correlated with benefit from treatment in the PDX models. In independent clinical validation, higher RT-GS scores were associated with increased survival only in patients receiving RT (P = 0.0031, hazard ratio [HR] = 0.78 [0.66-0.92]), higher Chemo-GS scores were associated with increased survival only in patients receiving chemotherapy (P < 0.0001, HR = 0.66 [0.55-0.8]), and higher ChemoRT-GS scores were associated with increased survival only in patients receiving ChemoRT (P = 0.0001, HR = 0.54 [0.4-0.74]). RT-GS and ChemoRT-GS had significant interactions with treatment on multivariate analysis (P = 0.0009 and 0.02, respectively), indicating that they are bona fide predictive biomarkers.

CONCLUSIONS

Using a novel PDX-driven methodology, we developed and validated 3 platform-independent molecular signatures that predict benefit from standard of care therapies for glioblastoma. These signatures may be useful to personalize glioblastoma treatment in the clinic and this approach may be a generalizable method to identify predictive biomarkers without resource-intensive randomized trials.

A validated integrated clinical and molecular glioblastoma long-term survival-predictive nomogram

Background

Glioblastoma (GBM) is the most common primary malignant brain tumor in adulthood. Despite multimodality treatments, including maximal safe resection followed by irradiation and chemotherapy, the median overall survival times range from 14 to 16 months. However, a small subset of GBM patients live beyond 5 years and are thus considered long-term survivors.

Methods

A retrospective analysis of the clinical, radiographic, and molecular features of patients with newly diagnosed primary GBM who underwent treatment at The University of Texas MD Anderson Cancer Center was conducted. Eighty patients had sufficient quantity and quality of tissue available for next-generation sequencing and immunohistochemical analysis. Factors associated with survival time were identified using proportional odds ordinal regression. We constructed a survival-predictive nomogram using a forward stepwise model that we subsequently validated using The Cancer Genome Atlas.

Results

Univariate analysis revealed 3 pivotal genetic alterations associated with GBM survival: both high tumor mutational burden (P = .0055) and PTEN mutations (P = .0235) negatively impacted survival, whereas IDH1 mutations positively impacted survival (P < .0001). Clinical factors significantly associated with GBM survival included age (P < .0001), preoperative Karnofsky Performance Scale score (P = .0001), sex (P = .0164), and clinical trial participation (P < .0001). Higher preoperative T1-enhancing volume (P = .0497) was associated with shorter survival. The ratio of TI-enhancing to nonenhancing disease (T1/T2 ratio) also significantly impacted survival (P = .0022).

Conclusions

Our newly devised long-term survival-predictive nomogram based on clinical and genomic data can be used to advise patients regarding their potential outcomes and account for confounding factors in nonrandomized clinical trials.

Treatment of Glioblastoma Multiforme in Elderly Patients. Clinico-therapeutic Remarks in 22 Patients Older than 80 Years

We report our remarks on 22 patients, 80 years of age and older, who were treated for glioblastoma multiforme. The 16 patients who underwent a multimodality treatment (surgery + radiotherapy + chemotherapy) had an average survival of 16.7 months versus the 5.8 months of the 8 patients treated with biopsy followed by radiotherapy and/or chemotherapy (log-rank test, P <0.001). Moreover, we point out the importance of MGMT hypermethylation as a significant prognostic factor: the 9 patients with nonmethylated MGMT had a mean survival of 7.7 months vs 17.9 months of the 13 patients with the MGMT promoter methylated (log-rank test, P = 0.0006). Several studies have pointed out age as an important negative factor for the outcome of elderly patients affected by glioblastoma multiforme. Elderly patients with a diagnosis of glioblastoma multiforme are thus generally excluded from clinical trials of treatment for the neoplasm, because it is a common opinion that the prognosis for such patients is particularly poor. On the contrary, according to our clinical and surgical experience, we firmly believe that patients older than 80 years with a histologically proven diagnosis of glioblastoma multiforme and in good health conditions (Karnofsky performance status >60) should be treated in the same way as younger patients.

Revisiting the Relationship Between Ethnicity and Outcome in Glioblastoma Patients

Background: Relationships between various ethnicities and glioma subtype have recently been established. As a tertiary referral center for Latin America and the Caribbean, our institution treats a diverse glioblastoma (GBM) population. We sought to clarify the role of ethnicity on patient prognosis in GBM and also compared these findings to a group consisting of elderly patients. We included ‘elderly’ as a group because the subgroups for ethnicities within them were too small. It allowed us to put in scope the effects of ethnicities on the overall survival. 

Material and Methods: After Institutional Review Board approval, 235 patients with GBM were retrospectively identified. A total of 140 patients were separated into four groups: White adults (n = 47), Hispanic adults (n = 27), elderly (n = 58), and Black adults (n = 6). Overall survival (OS) was our primary endpoint.

Results: Overall survival in the White adult group was 24.3 months, compared to 13.0 months in the Hispanic adult group, 20.2 months in the Black group, and 13.8 months in the elderly group (p = 0.01). In the Hispanic group, hypertension (37.9%, p = 0.01) and diabetes (24.1%, p = 0.009) were significantly more prevalent compared to the White adult cohort. No difference in insurance status or postoperative complications was found between subgroups.

Conclusion: Based on our analysis, Hispanic adults may have a decreased survival compared to White adults. However, the incidence of hypertension and diabetes was markedly higher in our Hispanic adult cohort; thus, estimating the risk of ethnicity and comorbidities on patient prognosis may be difficult. A prospective study correlating the genome and subgroup prognosis may help elucidate the role of ethnicity in GBM patients.

Long-term survival in glioblastoma: methyl guanine methyl transferase (MGMT) promoter methylation as independent favourable prognostic factor

Background

In spite of significant improvement after multi-modality treatment, prognosis of most patients with glioblastoma remains poor. Standard clinical prognostic factors (age, gender, extent of surgery and performance status) do not clearly predict long-term survival. The aim of this case-control study was to evaluate immuno-histochemical and genetic characteristics of the tumour as additional prognostic factors in glioblastoma.

Patients and methods

Long-term survivor group were 40 patients with glioblastoma with survival longer than 30 months. Control group were 40 patients with shorter survival and matched to the long-term survivor group according to the clinical prognostic factors. All patients underwent multimodality treatment with surgery, postoperative conformal radiotherapy and temozolomide during and after radiotherapy. Biopsy samples were tested for the methylation of MGMT promoter (with methylation specific polymerase chain reaction), IDH1 (with immunohistochemistry), IDH2, CDKN2A and CDKN2B (with multiplex ligation-dependent probe amplification), and 1p and 19q mutations (with fluorescent in situ hybridization).

Results

Methylation of MGMT promoter was found in 95% and in 36% in the long-term survivor and control groups, respectively (p < 0.001). IDH1 R132H mutated patients had a non-significant lower risk of dying from glioblastoma (p = 0.437), in comparison to patients without this mutation. Other mutations were rare, with no significant difference between the two groups.

Conclusions

Molecular and genetic testing offers additional prognostic and predictive information for patients with glioblastoma. The most important finding of our analysis is that in the absence of MGMT promoter methylation, longterm survival is very rare. For patients without this mutation, alternative treatments should be explored.

CXCL12 and CXCR4 as predictive biomarkers of glioma recurrence pattern after total resection

PURPOSE OF THE STUDY

Previous studies have shown that the pattern of recurrence for glioma is related to the direction of glioma cell invasion. Recent studies demonstrated that the CXCL12/CXCR4 signaling pathway mediates cellular invasion in glioma. Therefore, in this study, we investigated the possible relationship between CXCL12/CXCR4 expression and recurrence pattern in glioma.

PATIENTS AND METHODS

Immunohistochemical techniques were used to assess CXCL12/CXCR4 expression in 42 glioma tissues following total resection. According to magnetic resonance imaging (MRI) of gliomas, the recurrence pattern was classified as close or distant pattern. The relationship between recurrence pattern and CXCL12/CXCR4 expression were initially examined by Chi-squared analysis. The prognostic significance of CXCL12 and CXCR4 was determined by log-rank tests and COX proportional hazards model.

RESULTS

CXCL12 was expressed mainly in vascular endothelial cells and CXCR4 was expressed mainly in tumor cells. The recurrence pattern was significantly related to the expression level of CXCL12 in vascular endothelial cells (P=0.002) and CXCR4 in tumor cells (P=0.004). However, CXCL12 and CXCR4 were not independent prognostic factors for progression-free survival or overall survival in glioma patients.

CONCLUSION

The glioma recurrence pattern is related to CXCL12 expression levels in vascular endothelial cells and CXCR4 expression levels in tumor cells; thus, implicating the CXCL12/CXCR4 signaling pathway as a potential target for glioma therapy.

Age-associated brain regions in gliomas: a volumetric analysis

Both age of patients and tumor location are associated with tumor origin, genetic characteristics, and prognosis. The objective of this study was to investigate the relationship between tumor location and age at diagnosis in a large cohort of patients with a primary diagnosis of glioma. We consecutively enrolled a cohort of 200 adults with glioblastoma and another cohort of 200 adults with diffuse low-grade gliomas. The magnetic resonance images of all tumors were manually segmented and then registered to a standard brain space. By using voxel-by-voxel regression analysis, specific brains regions associated with advanced age at tumor diagnosis were localized. In the low-grade gliomas cohort, the brain regions associated with advanced age at tumor diagnosis were mainly located in the right middle frontal region, while a region in the left temporal lobe, particularly at the subgranular zone, was associated with lower age at tumor diagnosis. In the glioblastoma cohort, the brain regions associated with advanced age at tumor diagnosis were mainly located in the temporal lobe, particularly at the posterior region of the subventricular zones. A region in the left inferior frontal region was associated with lower age at tumor diagnosis. Significant differences in the age of patients were found between tumors located in the identified regions and those located elsewhere in both cohorts. The current study demonstrated the correlation between tumor location and age at diagnosis, which implies differences in the origin of gliomas in young and older patients.

High Jagged1 expression is associated with poor outcome in primary glioblastoma

Glioblastoma is a highly aggressive brain tumor. Aberrant Notch pathway has been implicated in the formation and progression of glioblastoma. The present study attempted to investigate the expression of Notch ligand Jagged1 and its association with patient outcome in primary glioblastoma. Tumor tissues from 82 patients with primary glioblastoma were analyzed using immunohistochemistry for Jagged1 expression. Relationships between Jagged1 expression and clinical features (age, gender, KPS, symptom duration, extent of resection and Ki67 index) were evaluated. The prognostic value of Jagged1 was assessed using the Kaplan-Meier survival estimates and the Cox proportional hazard models. Immunohistochemistry results showed markedly increased Jagged1 expression in glioblastoma tissues compared to adjacent non-neoplastic brain tissues. Univariate analysis documented that high Jagged1 expression in tumor cells (TC) and endothelial cells (EC) were both statistically associated with reduced time to progression (TTP) (P < 0.001 for TC, P = 0.001 for EC) and overall survival (OS) (P < 0.001 for TC, P = 0.003 for EC) in primary glioblastoma. The median TTP (P < 0.001) and OS (P = 0.001) were higher in patients with dual-low Jagged1 expression in TC and EC compared to those in patients with non-dual Jagged1 expression and dual high expression. By multivariate survival analysis, we found that high Jagged1 expression in both tumor cells and endothelial cells was independent unfavorable prognostic factors TTP (P < 0.001 for TC, P < 0.001 for TC) and OS (P < 0.001 for TC, P < 0.001 for TC) in primary glioblastoma patients. Jagged1-Notch signaling plays an important role in the progress of glioblastoma. Jagged1 expression may be used as an independent prognosis factor in patients with glioblastoma.

A computational model incorporating neural stem cell dynamics reproduces glioma incidence across the lifespan in the human population

Glioma is the most common form of primary brain tumor. Demographically, the risk of occurrence increases until old age. Here we present a novel computational model to reproduce the probability of glioma incidence across the lifespan. Previous mathematical models explaining glioma incidence are framed in a rather abstract way, and do not directly relate to empirical findings. To decrease this gap between theory and experimental observations, we incorporate recent data on cellular and molecular factors underlying gliomagenesis. Since evidence implicates the adult neural stem cell as the likely cell-of-origin of glioma, we have incorporated empirically-determined estimates of neural stem cell number, cell division rate, mutation rate and oncogenic potential into our model. We demonstrate that our model yields results which match actual demographic data in the human population. In particular, this model accounts for the observed peak incidence of glioma at approximately 80 years of age, without the need to assert differential susceptibility throughout the population. Overall, our model supports the hypothesis that glioma is caused by randomly-occurring oncogenic mutations within the neural stem cell population. Based on this model, we assess the influence of the (experimentally indicated) decrease in the number of neural stem cells and increase of cell division rate during aging. Our model provides multiple testable predictions, and suggests that different temporal sequences of oncogenic mutations can lead to tumorigenesis. Finally, we conclude that four or five oncogenic mutations are sufficient for the formation of glioma.

Glioblastoma multiforme - an overview

Glioblastoma multiforme is a central nervous system tumor of grade IV histological malignancy according to the WHO classification. Over 90% of diagnosed glioblastomas multiforme cases are primary gliomas, arising from normal glial cells through multistep oncogenesis. The remaining 10% are secondary gliomas originating from tumors of lower grade. These tumors expand distinctly more slowly. Although genetic alterations and deregulations of molecular pathways leading to both primary and secondary glioblastomas formation differ, morphologically they do not reveal any significant differences. Glioblastoma is a neoplasm that occurs spontaneously, although familial gliomas have also been noted. Caucasians, especially those living in industrial areas, have a higher incidence of glioblastoma. Cases of glioblastoma in infants and children are also reported. The participation of sex hormones and viruses in its oncogenesis was also suggested. Progression of glioblastoma multiforme is associated with deregulation of checkpoint G1/S of a cell cycle and occurrence of multiple genetic abnormalities of tumor cells. Metastases of glioblastoma multiforme are rarely described. Treatment of glioblastoma multiforme includes tumor resection, as well as radiotherapy and chemotherapy. Drugs inhibiting integrin signaling pathways and immunotherapy are also employed. Treatment modalities and prognosis depend on the tumor localization, degree of its malignancy, genetic profile, proliferation activity, patient's age and the Karnofsky performance scale score. Although the biology of glioblastoma multiforme has recently been widely investigated, the studies summarizing the knowledge of its development and treatment are still not sufficient in terms of comprehensive brain tumor analysis.

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.

Addition of MR imaging features and genetic biomarkers strengthens glioblastoma survival prediction in TCGA patients

PURPOSE

The purpose of our study was to assess whether a model combining clinical factors, MR imaging features, and genomics would better predict overall survival of patients with glioblastoma (GBM) than either individual data type.

METHODS

The study was conducted leveraging The Cancer Genome Atlas (TCGA) effort supported by the National Institutes of Health. Six neuroradiologists reviewed MRI images from The Cancer Imaging Archive (http://cancerimagingarchive.net) of 102 GBM patients using the VASARI scoring system. The patients' clinical and genetic data were obtained from the TCGA website (http://www.cancergenome.nih.gov/). Patient outcome was measured in terms of overall survival time. The association between different categories of biomarkers and survival was evaluated using Cox analysis.

RESULTS

The features that were significantly associated with survival were: (1) clinical factors: chemotherapy; (2) imaging: proportion of tumor contrast enhancement on MRI; and (3) genomics: HRAS copy number variation. The combination of these three biomarkers resulted in an incremental increase in the strength of prediction of survival, with the model that included clinical, imaging, and genetic variables having the highest predictive accuracy (area under the curve 0.679±0.068, Akaike's information criterion 566.7, P<0.001).

CONCLUSION

A combination of clinical factors, imaging features, and HRAS copy number variation best predicts survival of patients with GBM.

Key determinants of short-term and long-term glioblastoma survival: a 14-year retrospective study of patients from the Hermelin Brain Tumor Center at Henry Ford Hospital

OBJECTIVE

Glioblastoma (GBM) is a heterogeneous neoplasm with a small percentage of long-term survivors. Despite aggressive surgical resection and advances in radiotherapy and chemotherapy, the median survival for patients with GBM is 12-14 months. Factors associated with a favorable prognosis include young age, high performance status, gross resection >98%, non-eloquent tumor location and O6-methylguanine methyltransferase (MGMT) promoter methylation. We retrospectively analyzed the relationship of clinical, epidemiologic, genetic and molecular characteristics with survival in patients with GBM.

METHODS

This retrospective analysis of overall survival looked at the outcomes of 480 patients diagnosed with GBM over 14 years at a single institution. Multivariate analysis was performed examining multiple patient characteristics.

RESULTS

Median survival time improved from 11.8 months in patients diagnosed from 1995 to 1999 to 15.9 months in those diagnosed from 2005 to 2008. Factors associated with survivor groups were age, KPS, tumor resection, treatment received and early progression. 18 cancer-related genes were upregulated in short-term survivors and five genes were downregulated in short-term survivors.

CONCLUSIONS

Epidemiologic, clinical, and molecular characteristics all contribute to GBM prognosis. Identifying factors associated with survival is important for treatment strategies as well as research for novel therapeutics and technologies. This study demonstrated improved survival for patients over time as well as significant differences among survivor groups.

Recommendations for the management of malignant gliomas in the elderly

According to epidemiological estimations, the elderly are going to constitute an increasing proportion of patients with gliomas in the near future. Predominantly glioblastoma histology with invariably fatal outcome, disabling comorbidities and presumed low tolerability of radiochemotherapeutic treatments are the main reasons why elderly patients have been under-represented in the majority of neuro-oncological clinical trials conducted so far. Some small retrospective studies have reported that patients with good performance status receiving surgery plus radiotherapy, and sometimes chemotherapy, may achieve a survival comparable with that of younger patients, however, in the absence of randomized studies, the balance of benefits and adverse effects of aggressive treatments remains controversial. Multidisciplinary evaluation of prognostic factors, such as performance status, cognitive functions, tumor operability and burden of comorbidities, appears to be mandatory in order to choose which patients must not be deprived of an integrated treatment with surgery, full-dose radiotherapy and chemotherapy, and which patients may reasonably be given a shorter radiotherapy plan, or even no treatment at all due to the rapidly fatal course of their disease. Peculiar features of malignant gliomas in the elderly and some practical recommendations of management will be presented and discussed in this review.

The impact of age on oncogenic potential: tumor-initiating cells and the brain microenvironment

Paradoxically, aging leads to both decreased regenerative capacity in the brain and an increased risk of tumorigenesis, particularly the most common adult-onset brain tumor, glioma. A shared factor contributing to both phenomena is thought to be age-related alterations in neural progenitor cells (NPCs), which function normally to produce new neurons and glia, but are also considered likely cells of origin for malignant glioma. Upon oncogenic transformation, cells acquire characteristics known as the hallmarks of cancer, including unlimited replication, altered responses to growth and anti-growth factors, increased capacity for angiogenesis, potential for invasion, genetic instability, apoptotic evasion, escape from immune surveillance, and an adaptive metabolic phenotype. The precise molecular pathogenesis and temporal acquisition of these malignant characteristics is largely a mystery. Recent studies characterizing NPCs during normal aging, however, have begun to elucidate mechanisms underlying the age-associated increase in their malignant potential. Aging cells are dependent upon multiple compensatory pathways to maintain cell cycle control, normal niche interactions, genetic stability, programmed cell death, and oxidative metabolism. A few multi-functional proteins act as 'critical nodes' in the coordination of these various cellular activities, although both intracellular signaling and elements within the brain environment are critical to maintaining a balance between senescence and tumorigenesis. Here, we provide an overview of recent progress in our understanding of how mechanisms underlying cellular aging inform on glioma pathogenesis and malignancy.

Concomitant and adjuvant temozolomide of newly diagnosed glioblastoma in elderly patients

OBJECTIVE

The effect of concomitant and adjuvant temozolomide in glioblastoma patients above the age of 65 years lacks evidence. However, after combined treatment became standard at our center all patients were considered for combined therapy. We retrospectively analyzed the effect of temozolomide focused on elderly patients.

METHODS

293 patients with newly diagnosed glioblastoma treated single-centered between 1998 and 2010, by radiation alone or concomitant and adjuvant radiochemotherapy, were included. Treatment groups were analyzed by multi- and univariate analysis. Matched pairs for age, by a 5-year-caliper, extent of resection and general state was generated for all patients and elderly subgroups.

RESULTS

103 patients received radiation only and 190 combined treatment. Multivariate and matched pair analysis revealed a benefit due to combined temozolomide (HR 1.895 and 1.752, respectively). For patients older than 65 years median survival was 3.6 (95% CI 3.2-4.7) and 8.7 months (6.3-11.8) for radiotherapy only and combined treatment (HR 3.097, p<0.0001, n=90). Over the age of 70 and 75 years median survival was 3.2 (2.3-4.2) vs. 7.5 (5.1-10.9, HR 4.453, p<0.0001, n=62) and 3.2 (1.4-3.9) vs. 9.2 months (4.7-13.5; HR 9.037, p<0.0001, n=24), respectively. In 8/56 (14%) patients over the age of 70 years temozolomide was terminated due to toxicity.

CONCLUSION

Retrospective matched pair analysis gives class 2b evidence for prolonged survival due to concomitant and adjuvant temozolomide in elderly glioblastoma patients. Until prospective data for combined radiochemotherapy in elderly patients will be available concomitant and adjuvant temozolomide therapy should not be withheld.

The immunohistochemical expression of c-Met is an independent predictor of survival in patients with glioblastoma multiforme

BACKGROUND AND AIMS

Because the outcome of glioblastoma multiforme (GBM) remains dismal, there is an urgent need for a better molecular characterization of this malignancy. The aim of this prospective study was to investigate the prognostic impact of the expression of c-mesenchymal-epithelial transition (c-Met) a receptor tyrosine kinase implicated in expression growth, survival, motility/migration, and invasion in GMB patients managed according to the established diagnostic and therapeutic protocols.

METHODS

Between May 2003 and March 2011, a total of 69 patients (33 males and 36 females; mean age: 52.2 ± 12.9 years, age range: 23-81 years) referred to our Department for the surgical removal of GBM were evaluated immunohistochemically for c-Met expression. Progression-free survival (PFS) and overall survival (OS) served as the main outcome measures.

RESULTS

Compared with c-Met- subjects (n = 38), c-Met+ subjects (n = 31) had both a significantly lower OS (15.3 ± 2.3 vs. 22.6 ± 2.5 months, respectively, p < 0.01) and PFS (12.3 ± 2.1 vs. 19.1 ± 2.6 months, respectively, p < 0.05). After allowance for potential confounders, multivariate Cox regression analysis identified c-Met+ as an independent predictor of both OS (hazard ratio = 1.7; 95 % confidence interval = 1.2-1.9, p < 0.01) and PFS (hazard ratio = 1.6; 95 % confidence interval = 1.1-2.3, p < 0.05).

CONCLUSIONS

Our findings suggest that c-Met immunohistochemical expression is an independent predictor of outcomes in patients with GBM treated by standard of care.

Recovery of white matter tracts in regions of peritumoral FLAIR hyperintensity with use of restriction spectrum imaging

BACKGROUND AND PURPOSE

DTI is being increasingly used to visualize critical white matter tracts adjacent to brain tumors before neurosurgical resection. However, brain tumors, particularly high-grade gliomas, are typically surrounded by regions of FLAIR hyperintensity that include edema, which increase isotropic diffusion, degrading the ability of standard DTI to uncover orientation estimates within these regions. We introduce a new technique, RSI, which overcomes this limitation by removing the spherical, fast diffusion component introduced by edema, providing better analysis of white matter architecture.

MATERIALS AND METHODS

A total of 10 patients with high-grade gliomas surrounded by FLAIR-HI that at least partially resolved on follow-up imaging were included. All patients underwent RSI and DTI at baseline (FLAIR-HI present) and at follow-up (FLAIR-HI partially resolved). FA values obtained with RSI and DTI were compared within regions of FLAIR-HI and NAWM at both time points.

RESULTS

RSI showed higher FA in regions of FLAIR-HI and NAWM relative to DTI, reflecting the ability of RSI to specifically measure the slow, restricted volume fraction in regions of edema and NAWM. Furthermore, a method by time interaction revealed that FA estimates increased when the FLAIR-HI resolved by use of standard DTI but remained stable with RSI. Tractography performed within the region of FLAIR-HI revealed the superior ability of RSI to track fibers through severe edema relative to standard DTI.

CONCLUSIONS

RSI improves the quantification and visualization of white matter tracts in regions of peritumoral FLAIR-HI associated with edema relative to standard DTI and may provide a valuable tool for neurosurgical planning.

Predictors of long-term survival in patients with glioblastoma multiforme: advancements from the last quarter century

Over the last quarter century there has been significant progress toward identifying certain characteristics and patterns in GBM patients to predict survival times and outcomes. We sought to identify clinical predictors of survival in GBM patients from the past 24 years. We examined patient survival related to tumor locations, surgical treatment, postoperative course, radiotherapy, chemotherapy, patient age, GBM recurrence, imaging characteristics, serum, and molecular markers. We present predictors that may increase, decrease, or play no significant role in determining a GBM patient's long-term survival or affect the quality of life.

Increased age of transformed mouse neural progenitor/stem cells recapitulates age-dependent clinical features of human glioma malignancy

Increasing age is the most robust predictor of greater malignancy and treatment resistance in human gliomas. However, the adverse association of clinical course with aging is rarely considered in animal glioma models, impeding delineation of the relative importance of organismal versus progenitor cell aging in the genesis of glioma malignancy. To address this limitation, we implanted transformed neural stem/progenitor cells (NSPCs), the presumed cells of glioma origin, from 3- and 18-month-old mice into 3- and 20-month host animals. Transplantation with progenitors from older animals resulted in significantly shorter (P ≤ 0.0001) median survival in both 3-month (37.5 vs. 83 days) and 20-month (38 vs. 67 days) hosts, indicating that age-dependent changes intrinsic to NSPCs rather than host animal age accounted for greater malignancy. Subsequent analyses revealed that increased invasiveness, genomic instability, resistance to therapeutic agents, and tolerance to hypoxic stress accompanied aging in transformed NSPCs. Greater tolerance to hypoxia in older progenitor cells, as evidenced by elevated HIF-1 promoter reporter activity and hypoxia response gene (HRG) expression, mirrors the upregulation of HRGs in cohorts of older vs. younger glioma patients revealed by analysis of gene expression databases, suggesting that differential response to hypoxic stress may underlie age-dependent differences in invasion, genomic instability, and treatment resistance. Our study provides strong evidence that progenitor cell aging is responsible for promoting the hallmarks of age-dependent glioma malignancy and that consideration of progenitor aging will facilitate development of physiologically and clinically relevant animal models of human gliomas.

Hypofractionated Radiotherapy and Stereotactic Boost with Concurrent and Adjuvant Temozolamide for Glioblastoma in Good Performance Status Elderly Patients - Early Results of a Phase II Trial

Glioblastoma Multiforme (GBM) is an aggressive primary brain neoplasm with dismal prognosis. Based on successful phase III trials, 60 Gy involved-field radiotherapy in 30 fractions over 6 weeks [Standard radiation therapy (RT)] with concurrent and adjuvant temozolomide is currently the standard of care. In this disease, age and Karnofsky Performance Status (KPS) are the most important prognostic factors. For elderly patients, clinical trials comparing standard RT with radiotherapy abbreviated to 40 Gy in 15 fractions over 3 weeks demonstrated similar outcomes, indicating shortened radiotherapy may be an appropriate option for elderly patients. However, these trials did not include temozolomide chemotherapy, and included patients with poor KPS, possibly obscuring benefits of more aggressive treatment for some elderly patients. We conducted a prospective Phase II trial to examine the efficacy of a hypofractionated radiation course followed by a stereotactic boost with concurrent and adjuvant temozolomide chemotherapy in elderly patients with good performance status. In this study, patients 65 years and older with a KPS > 70 and histologically confirmed GBM received 40 Gy in 15 fractions with 3D conformal technique followed by a 1–3 fraction stereotactic boost to the enhancing tumor. All patients also received concurrent and adjuvant temozolomide. Patients were evaluated 1 month post-treatment and every 2 months thereafter. Between 2007 and 2010, 20 patients (9 males and 11 females) were enrolled in this study. The median age was 75.4 years (range 65–87 years). At a median follow-up of 11 months (range 7–32 months), 12 patients progressed and 5 are alive. The median progression free survival was 11 months and the median overall survival was 13 months. There was no additional toxicity. These results indicate that elderly patients with good KPS can achieve outcomes comparable to the current standard of care using an abbreviated radiotherapy course, radiosurgery boost, and temozolomide.

Volumetric response evaluation after intensity modulated radiotherapy in patients with supratentorial gliomas

Radiotherapy is frequently indicated to treat cerebral gliomas. Accurate response evaluation after radiotherapy is essential to determine the efficacy of treatment. We retrospectively analyzed the volumetric tumor response after simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) in patients with gliomas. Thirty-five patients (Grade II, 7 patients; Grade III, 12; and Grade IV, 16) were treated with SIB-IMRT with a median total dose of 55.9 Gy/26 fractions for Grade II and 60 Gy/25 fractions for Grade III-IV tumors. Tumor responses were evaluated for enhancing volume on post-gadolinium T1-weighted images (Vgd) and hyper-intensity volume on T2-weighted FLAIR images (V(fl)) on serial MRIs. With the median follow-up of 24.0 months, overall response rates (RRs) were 57% for V(gd) and 51% for V(fl). Tumor grade was predictive of response favoring the lower grade in Vfl with RRs of 86% for Grade II, 75% for Grade III, and 19% for Grade IV tumors (p = 0.004). Time to 50% or greater volume reduction (T50) in Vgd was 8 months for grade III. The T50 in V(fl) was approximately 24 months both for Grade II and III tumors. Majority of Grade IV tumors continued to progress and never reached the T50 in Vgd or Vfl. Responders survived longer than non-responders for V(gd) and V(fl). Volume response after radiotherapy was dependent upon tumor grade and time. LGGs are very responsive to radiotherapy with the RRs of 86% in V(fl). The response of Vfl is more protracted compared to V(gd). Further investigation is needed to determine the clinical significance of volumetric response evaluation.

Increased re-entry into cell cycle mitigates age-related neurogenic decline in the murine subventricular zone

Although new neurons are produced in the subventricular zone (SVZ) of the adult mammalian brain, fewer functional neurons are produced with increasing age. The age-related decline in neurogenesis has been attributed to a decreased pool of neural progenitor cells (NPCs), an increased rate of cell death, and an inability to undergo neuronal differentiation and develop functional synapses. The time between mitotic events has also been hypothesized to increase with age, but this has not been directly investigated. Studying primary-cultured NPCs from the young adult and aged mouse forebrain, we observe that fewer aged cells are dividing at a given time; however, the mitotic cells in aged cultures divide more frequently than mitotic cells in young cultures during a 48-hour period of live-cell time-lapse imaging. Double-thymidine-analog labeling also demonstrates that fewer aged cells are dividing at a given time, but those that do divide are significantly more likely to re-enter the cell cycle within a day, both in vitro and in vivo. Meanwhile, we observed that cellular survival is impaired in aged cultures. Using our live-cell imaging data, we developed a mathematical model describing cell cycle kinetics to predict the growth curves of cells over time in vitro and the labeling index over time in vivo. Together, these data surprisingly suggest that progenitor cells remaining in the aged SVZ are highly proliferative.

Glioblastoma therapy in the elderly and the importance of the extent of resection regardless of age

OBJECT

The objective of this study was to analyze whether age influences the outcome of patients with glioblastoma and whether elderly patients with glioblastoma can tolerate the same aggressive treatment as younger patients.

METHODS

Data from 361 consecutive patients with newly diagnosed cerebral glioblastoma (2000-2006) who underwent regular follow-up evaluation from initial diagnosis until death were prospectively entered into a database. Patients underwent resection (complete, subtotal, or partial) or biopsy, depending on tumor size, location, and Karnofsky Performance Scale score. Following surgery, all patients underwent adjuvant treatment consisting of radiotherapy, chemotherapy, or combined treatment. Patients older than 65 years of age were defined as elderly (146 total).

RESULTS

Two hundred thirty-four patients underwent tumor resection (complete 26%, subtotal 29%, and partial 45%). One hundred twenty-seven underwent biopsy. Mean patient age was 61 years, and overall survival was 11.6 ± 12.1 months. The overall survival of elderly patients (9.1 ± 11.6 months) was significantly lower than that of younger patients (14.9 ± 16.7 months; p = 0.0001). Stratifying between resection or biopsy, age was a negative prognostic factor in patients undergoing biopsy (4.0 ± 7.1 vs 7.9 ± 8.7 months; p = 0.007), but not in patients undergoing tumor resection (13.0 ± 8.5 vs 13.3 ± 14.5 months; p = 0.86). Survival of elderly patients undergoing complete tumor resection was 17.7 ± 8.1 months.

CONCLUSIONS

In this series of patients with glioblastoma, age was a prognostic factor in patients undergoing biopsy, but not in patients undergoing resection. Tumor location and patient clinical status may prohibit extensive resection, but resection should not be withheld from patients only on the basis of age. In elderly patients with glioblastoma, undergoing resection to the extent feasible, followed by adjuvant therapies, is warranted.

Treatment outcomes for patients with glioblastoma multiforme and a low Karnofsky Performance Scale score on presentation to a tertiary care institution. Clinical article

OBJECT

The object of this study was to determine the benefit of surgery, radiation, and chemotherapy for patients with glioblastoma multiforme (GBM) and a low Karnofsky Performance Scale (KPS) score.

METHODS

The authors retrospectively evaluated the records of patients who underwent primary treatment for pathologically confirmed GBM and with a KPS score ≤ 50 on initial evaluation for radiation therapy at a tertiary care institution between 1977 and 2006. Seventy-four patients with a median age of 69 years (range 19-88 years) and a median KPS score of 50 (range 20-50) were retrospectively grouped into the Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) Classes IV (11 patients), V (15 patients), and VI (48 patients). Patients underwent biopsy (38 patients) or tumor resection (36 patients). Forty-seven patients received radiation. Nineteen patients also received chemotherapy (53% temozolomide), initiated concurrently (47%) or after radiotherapy.

RESULTS

The median survival overall was 2.3 months (range 0.2-48 months). Median survival stratified by RPA Classes IV, V, and VI was 6.6, 6.6, and 1.8 months, respectively (p < 0.001, log-rank test). Median survival for patients receiving radiation (5.2 months) was greater than that for patients who declined radiation (1.6 months, p < 0.001). Patients in RPA Class VI appeared to benefit from radiotherapy only when tumor resection was also performed. The median survival from treatment initiation was greater for patients receiving chemotherapy concomitantly with radiotherapy (9.8 months) as compared with radiotherapy alone (1.7 months, p = 0.002). Of 20 patients seen for follow-up in the clinic at a median of 48 days (range 24-196 days) following radiotherapy, 70% were noted to have an improvement in the KPS score of between 10 and 30 points from the baseline score. On multivariate analysis, only RPA class (p = 0.01), resection (HR = 0.37, p = 0.001), and radiation therapy (HR = 0.39, p = 0.02) were significant predictors of a decreased mortality rate.

CONCLUSIONS

Patients with a KPS score ≤ 50 appear to have increased survival and functional status following tumor resection and radiation. The extent of benefit from concomitant chemotherapy is unclear. Future studies may benefit from reporting that utilizes a prognostic classification system such as the RTOG RPA class, which has been shown to be effective at separating outcomes even in patients with low performance status. Patients with GBMs and low KPS scores need to be evaluated in prospective studies to identify the extent to which different therapies improve outcomes.

Glioblastoma multiforme of the elderly: the prognostic effect of resection on survival

According to recent developments the best treatment options for glioblastoma (GBM) consist in maximum safe resection and additional adjuvant treatment with radiotherapy (RT) and alkylating chemotherapy (CHX). These options have been evaluated for populations with a median age of approximately 58 years. We therefore addressed the issue of whether elderly patients (>65 years) could also benefit from cytoreductive surgery (CS) and adjuvant treatment using alkylating chemotherapy. One-hundred and three patients suffering from newly diagnosed, primary supratentorial glioblastoma multiforme >65 years (median 70.8 years) were identified in our single-center glioma database (2002-2007) and retrospectively divided into group A (n = 31) treated with surgery alone (biopsy, BY, n = 21, CS n = 10), group B (n = 37) surgery plus radiation (BY n = 18, CS n = 19), and group C (n = 35) surgery, RT and CHX (BY n = 4, CS n = 31). Progression-free survival (PFS) and overall survival (OAS) were determined in each group and correlated to age, Karnofsky performance score (KPS), and extent of resection (biopsy (BY), partial (PR), and complete resection (CR)). Progression was defined according the Macdonald criteria. For all patients PFS and OAS were 3.2 months and 5.1 months (m) respectively. PFS and OAS for groups A/B/C were 1.8/3.2/6.4 m (P = 0.000) and 2.2/4.4/15.0 m (P = 0.000), respectively. Median age for groups A/B/C was 74.4/70.6/68.5 years and median KPS was 60/70/80. Age (<75, ≥75) was inversely correlated with OAS (5.8/2.5 m, P = 0.01). KPS (<70, ≥70) was correlated with OAS 2.4/6.5 m (P = 0.000). Extent of resection (BY, PR, or CR) correlated with PFS (2.1/3.4/6.4 m, P = 0,000) and OS (2.2/7.0/13.9 m, P = 0,000), respectively. Our study shows that elderly GBM patients can benefit from maximum treatment procedures with cytoreductive microsurgery, radiation therapy, and chemotherapy. Treatment options are obviously affected by KPS and age. The most impressive outcome predictor in this population was the extent of microsurgical resection for patients treated with adjuvant radiotherapy and chemotherapy. To conclude, elderly GBM patients should not be per se excluded from intensive treatment procedures.

MGMT promoter methylation is predictive of response to radiotherapy and prognostic in the absence of adjuvant alkylating chemotherapy for glioblastoma

Hypermethylation of the O(6)-methylguanine-DNA-methyltransferase (MGMT) gene has been shown to be associated with improved outcome in glioblastoma (GBM) and may be a predictive marker of sensitivity to alkylating agents. However, the predictive utility of this marker has not been rigorously tested with regard to sensitivity to other therapies, namely radiation. To address this issue, we assessed MGMT methylation status in a cohort of patients with GBM who underwent radiation treatment but did not receive chemotherapy as a component of adjuvant treatment. Formalin-fixed, paraffin-embedded tumor samples from 225 patients with newly diagnosed GBM were analyzed via methylation-specific, quantitative real-time polymerase chain reaction following bisulfite treatment on isolated DNA to assess MGMT promoter methylation status. In patients who received radiotherapy alone following resection, methylation of the MGMT promoter correlated with an improved response to radiotherapy. Unmethylated tumors were twice as likely to progress during radiation treatment. The median time interval between resection and tumor progression of unmethylated tumors was also nearly half that of methylated tumors. Promoter methylation was also found to confer improved overall survival in patients who did not receive adjuvant alkylating chemotherapy. Multivariable analysis demonstrated that methylation status was independent of age, Karnofsky performance score, and extent of resection as a predictor of time to progression and overall survival. Our data suggest that MGMT promoter methylation appears to be a predictive biomarker of radiation response. Since this biomarker has also been shown to predict response to alkylating agents, perhaps MGMT promoter methylation represents a general, favorable prognostic factor in GBM.

A syngeneic glioma model to assess the impact of neural progenitor target cell age on tumor malignancy

Human glioma incidence, malignancy, and treatment resistance are directly proportional to patient age. Cell intrinsic factors are reported to contribute to human age-dependent glioma malignancy, but suitable animal models to examine the role of aging are lacking. Here, we developed an orthotopic syngeneic glioma model to test the hypothesis that the age of neural progenitor cells (NPCs), presumed cells of glioma origin, influences glioma malignancy. Gliomas generated from transformed donor 3-, 12-, and 18-month-old NPCs in same-aged adult hosts formed highly invasive glial tumors that phenocopied the human disease. Survival analysis indicated increased malignancy of gliomas generated from older 12- and 18-month-old transformed NPCs compared with their 3-month counterparts (median survival of 38.5 and 42.5 vs. 77 days, respectively). This study showed for the first time that age of target cells at the time of transformation can affect malignancy and demonstrated the feasibility of a syngeneic model using transformed NPCs for future examination of the relative impacts of age-related cell intrinsic and cell-extrinsic factors in glioma malignancy.

Brain tumor epidemiology: consensus from the Brain Tumor Epidemiology Consortium

Epidemiologists in the Brain Tumor Epidemiology Consortium (BTEC) have prioritized areas for further research. Although many risk factors have been examined over the past several decades, there are few consistent findings, possibly because of small sample sizes in individual studies and differences between studies in patients, tumor types, and methods of classification. Individual studies generally have lacked samples of sufficient size to examine interactions. A major priority based on available evidence and technologies includes expanding research in genetics and molecular epidemiology of brain tumors. BTEC has taken an active role in promoting understudied groups, such as pediatric brain tumors; the etiology of rare glioma subtypes, such as oligodendroglioma; and meningioma, which, although it is not uncommon, has only recently been registered systematically in the United States. There also is a pressing need for more researchers, especially junior investigators, to study brain tumor epidemiology. However, relatively poor funding for brain tumor research has made it difficult to encourage careers in this area. In this report, BTEC epidemiologists reviewed the group's consensus on the current state of scientific findings, and they present a consensus on research priorities to identify which important areas the science should move to address.

Patterns of practice and survival in a retrospective analysis of 1722 adult astrocytoma patients treated between 1985 and 2001 in 12 Italian radiation oncology centers

PURPOSE

To analyze the patterns of practice and survival in a series of 1722 adult astrocytoma patients treated in 12 Italian radiotherapy centers.

METHODS AND MATERIALS

A total of 1722 patients were treated with postoperative radiotherapy (90% World Health Organization [WHO] Grade 3-4, 62% male, 44% aged >60 years, 25% with severe neurologic deficits, 44% after gross total resection, 52% with high-dose radiotherapy, and 16% with chemotherapy). Variations in the clinical-therapeutic features in three subsequent periods (1985 through 2001) were evaluated, along with overall survival for the different subgroups.

RESULTS

The proportion of women, of older patients, of those with worse neurologic performance status (NPS), with WHO Grade 4, and with smaller tumors increased with time, as did the proportion of those treated with radical surgery, hypofractionated radiotherapy, and more sophisticated radiotherapy techniques, after staging procedures progressively became more accurate. The main prognostic factors for overall survival were age, sex, neurologic performance status, WHO grade, extent of surgery, and radiation dose.

CONCLUSIONS

Recently, broader selection criteria for radiotherapy were adopted, together with simpler techniques, smaller total doses, and larger fraction sizes for the worse prognostic categories. Younger, fit patients are treated more aggressively, more often in association with chemotherapy. Survival did not change over time. The accurate evaluation of neurologic status is therefore of utmost importance before the best treatment option for the individual patient is chosen.

Survival outcomes in glioblastoma multiforme, including the impact of adjuvant chemotherapy

Glioblastoma is an uncommon cancer, but one that is disproportionately represented in mortality rates. Recent developments in adjuvant chemotherapy have regenerated enthusiasm for the treatment of this tumor. Ongoing translational and clinical research has led to a greater understanding of the biologic and molecular behavior and heterogeneity of this tumor. Recent shifts in treatment standards, as well as further selective individualizing of therapies based on molecular information, promise progress for this difficult-to-treat neoplasm.

Glioblastoma multiforme in the elderly: a therapeutic challenge

INTRODUCTION

Elderly patients with glioblastoma multiforme (GBM) are frequently excluded from cancer therapy trials, treated suboptimally or not treated at all. The average survival in elderly patients is 4-8 months. The goal of the present study was to evaluate the efficacy of different treatment options in terms of survival in an elderly population affected with GBM.

MATERIALS AND METHODS

About 34 Patients with primary supratentorial GBM aged 65 or higher were included in this study. All patients underwent craniotomy and tumor mass resection. After surgery they received radiation therapy, chemotherapy and radioimmunotherapy in different combinations.

RESULTS

Overall median survival was 10.5 months with one patient still alive at 35 months. Survival was longer for patients who underwent total resection instead of partial (13 months vs 4 months, P=0.006). If total en-bloc resection was used a further survival advantage was obtained (16 months for en-bloc resection, 9 months for inside-out resection, P=0.008). Where a second surgical intervention was performed median survival was 21 months (P=0.05). Survival according to adjuvant therapy has been 21 months (radiotherapy, chemotherapy, radioimmunotheraphy), 18 months (radiotherapy, chemotherapy) and 7 months (radiotherapy) (P=0.0001).

CONCLUSIONS

We think that single prognostic factor such as age should be not a reason for undertreatment.

Modified boron neutron capture therapy for malignant gliomas performed using epithermal neutron and two boron compounds with different accumulation mechanisms: an efficacy study based on findings on neuroimages

OBJECT

To improve the effectiveness of boron neutron capture therapy (BNCT) for malignant gliomas, the authors used epithermal rather than thermal neutrons for deep penetration and two boron compounds-sodium borocaptate (BSH) and boronophenylalanine (BPA)-with different accumulation mechanisms to increase the boron level in tumors while compensating for each other's faults.

METHODS

Thirteen patients, 10 of whom harbored a glioblastoma multiforme (GBM), one a gliosarcoma, one an anaplastic astrocytoma, and one an anaplastic oligoastrocytoma, were treated using this modified BNCT between January 2002 and December 2003. Postoperatively, neuroimaging revealed that only one patient with a GBM had no lesion enhancement postoperatively. The patients underwent 18F-BPA positron emission tomography, if available, to assess the accumulation and distribution of BPA before neutron radiotherapy. The neutron fluence rate was estimated using the Simulation Environments for Radiotherapy Applications dose-planning system before irradiation. The patients' volume assessments were performed using magnetic resonance (MR) imaging or computerized tomography (CT) scanning. Improvements in the disease as seen on neuroimages were assessed between 2 and 7 days after irradiation to determine the initial effects of BNCT; its maximal effects were also analyzed on serial neuroimages. The mean tumor volume before BNCT was 42.3 cm3. Regardless of the pre-BNCT tumor volume, in every patient harboring an assessable lesion, improvements on MR or CT images were recognized both at the initial assessment (range of volume reduction rate 17.4-71%, mean rate 46.4%) and at follow-up assessments (range of volume reduction rates 30.3-87.6%, mean rate 58.5%). More than 50% of the contrast-enhanced lesions disappeared in eight of the 12 patients during the follow-up period.

CONCLUSIONS

This modified BNCT produced a good improvement in malignant gliomas, as seen on neuroimages.

Concurrent chemoradiotherapy and adjuvant chemotherapy with Topotecan for patients with glioblastoma multiforme

PURPOSE

The prognosis for patients with glioblastoma multiforme remains poor. Phase II studies, meta-analyses and a phase III study show that concurrent chemoradiotherapy has an advantage over irradiation alone. In this study the effectiveness of concurrent chemoradiotherapy with Topotecan and an adjuvant chemotherapy with Topotecan was investigated.

PATIENTS AND METHOD

Forty-two patients with predominantly unfavourable prognosis factors were included in the study and treated as follows: hyperfractionated accelerated radiotherapy (2x1.75Gy to 45.5 + 12.25 Gy (RP)) with a concurrent, continuous infusion of Topotecan (0.5 mg/m(2)/d, days 1-21). On day 28 the adjuvant chemotherapy (three courses) was begun according to the same scheme.

RESULT

Haematological toxicities were 13/42 (30%) grade III leucopenia, 2/42 (4%) grade IV, as well as 5/42 (10%) grade III thrombopenias and 1/42 (2%) grade IV. 30/42 (71%) patients showed improvement or stabilisation of an existing neurological symptomatic complex. The median time to progression was 7.2 (+/- 0.8) months, the median total survival was 10 (+/- 1.2) months, the 2 year survival rate 4.7 (+/- 0.3)%. Prognostic factors were age, surgical radicality, performance status and the tumour volume before therapy.

SUMMARY

Concurrent chemoradiotherapy and an adjuvant chemotherapy with Topotecan is feasible at acceptable toxicity levels also for patients with a moderate performance status. The patients benefit from the improvement of the clinical symptomatic complex and, even with unfavourable prognosis factors, have a higher median survival in comparison to data published on similar groups of patients given only radiotherapy.

The molecular epidemiology of gliomas in adults

In this paper the authors highlight recent findings from molecular epidemiology studies of glioma origin and prognosis and suggest promising paths for future research. The reasons for variation in glioma incidence according to time period of diagnosis, sex, age, ancestry and ethnicity, and geography are poorly understood, as are factors that affect prognosis. High-dose therapeutic ionizing irradiation and rare mutations in highly penetrant genes associated with certain rare syndromes—the only two established causes of glioma—can be called upon to explain few cases. Both familial aggregation of gliomas and the inverse association of allergies and immune-related conditions with gliomas have been shown consistently, but the explanations for these associations are inadequately developed or unknown. Several bio-markers do predict prognosis, but only evaluation of loss of 1p and 19q in oligodendroglial tumors are incorporated in clinical practice. Ongoing research focuses on classifying homogeneous groups of tumors on the basis of molecular markers and identifying inherited polymorphisms that may influence survival or risk. Because most cases of glioma have yet to furnish either an environmental or a genetic explanation, the greatest potential for discovery may lie in genomic studies in conjunction with continued evaluation of environmental and developmental factors. Large sample sizes and multidisciplinary teams with expertise in neuropathology, genetics, epidemiology, functional genomics, bioinformatics, biostatistics, immunology, and neurooncology are required for these studies to permit exploration of potentially relevant pathways and modifying effects of other genes or exposures, and to avoid false-positive findings. Improving survival rates for patients harboring astrocytic tumors will probably require many randomized clinical trials of novel treatment strategies.

Phase 2 trial of copper depletion and penicillamine as antiangiogenesis therapy of glioblastoma

Penicillamine is an oral agent used to treat intracerebral copper overload in Wilson's disease. Copper is a known regulator of angiogenesis; copper reduction inhibits experimental glioma growth and invasiveness. This study examined the feasibility, safety, and efficacy of creating a copper deficiency in human glioblastoma multiforme. Forty eligible patients with newly diagnosed glioblastoma multiforme began radiation therapy (6000 cGy in 30 fractions) in conjunction with a low-copper diet and escalating doses of penicillamine. Serum copper was measured at baseline and monthly. The primary end point of this study was overall survival compared to historical controls within the NABTT CNS Consortium database. The 25 males and 15 females who were enrolled had a median age of 54 years and a median Karnofsky performance status of 90. Surgical resection was performed in 83% of these patients. Normal serum copper levels at baseline (median, 130 microg/dl; range, 50-227 microg/dl) fell to the target range of <50 microg/dl (median, 42 microg/dl; range, 12-118 microg/dl) after two months. Penicillamine-induced hypocupremia was well tolerated for months. Drug-related myelosuppression, elevated liver function tests, and skin rash rapidly reversed with copper repletion. Median survival was 11.3 months, and progression-free survival was 7.1 months. Achievement of hypocupremia did not significantly increase survival. Although serum copper was effectively reduced by diet and penicillamine, this antiangiogenesis strategy did not improve survival in patients with glioblastoma multiforme.

YKL-40 expression is associated with poorer response to radiation and shorter overall survival in glioblastoma

PURPOSE

YKL-40 is a secreted protein that has been reported to be overexpressed in epithelial cancers and gliomas, although its function is unknown. Previous data in a smaller sample set suggested that YKL-40 was a marker associated with a poorer clinical outcome and a genetically defined subgroup of glioblastoma. Here we test these findings in a larger series of patients with glioblastoma, and in particular, determine if tumor YKL-40 expression is associated with radiation response.

EXPERIMENTAL DESIGN

Patients (n=147) with subtotal resections were studied for imaging-assessed changes in tumor size in serial studies following radiation therapy. An additional set (n=140) of glioblastoma patients who underwent a gross-total resection was tested to validate the survival association and extend them to patients with minimal residual disease.

RESULTS

In the subtotal resection group, higher YKL-40 expression was significantly associated with poorer radiation response, shorter time to progression and shorter overall survival. The association of higher YKL-40 expression with poorer survival was validated in the gross-total resection group. In multivariate analysis with both groups combined (n = 287), YKL-40 was an independent predictor of survival after adjusting for patient age, performance status, and extent of resection. YKL-40 expression was also compared with genetically defined subsets of glioblastoma by assessing epidermal growth factor receptor amplification and loss at chromosome 10q, two of the common recurring aberrations in these tumors, using fluorescent in situ hybridization. YKL-40 was significantly associated with 10q loss.

CONCLUSIONS

The findings implicate YKL-40 as an important marker of therapeutic response and genetic subtype in glioblastomas and suggest that it may play an oncogenic role in these tumors.

The treatment of malignant gliomas

The optimal management of patients with malignant gliomas begins with the accurate determination of the pathologic diagnosis based on adequate sampling of the tumor. Clear differences in prognosis and therapeutic options have been established for the various tumor grades and cellular classification. Current recommendations, on the basis of the results of a recent phase III randomized trial, are that patients with glioblastoma should have maximal surgical resection followed by concurrent radiation and chemotherapy with temozolomide. It is further recommended that patients then be treated with 6 to 12 months of adjuvant temozolomide. However, despite the shown improvement in survival with this chemoradiation regimen, the impact on outcome is modest. It is increasingly evident that a greater understanding of the molecular mechanisms of gliomagenesis is needed to improve treatments for these patients. Recent and ongoing investigations strongly indicate that specific molecular markers tremendously impact prognosis and often can predict response to treatment. For example, allelic loss of the 1p and 19q chromosome arms predicts a dramatic improvement in response to treatment and survival for tumors histologically classified as anaplastic oligodendroglioma. Future advances for treating primary brain tumors likely will be directly related to our ability to molecularly subcategorize tumors and customize therapy based on the molecular profile within each histologic type and grade of tumor. This is evident in preliminary data indicating that inactivation of the methyl guanine methyltransferase gene by hypermethylation of the promoter region specifically predicts a better tumor response rate to chemotherapies that alkylate DNA as their mechanism of action. Similarly, elucidation of overly active signal transduction pathways within tumor cells may provide an opportunity to select the optimal therapeutic regimen composed of modulators of these pathways, analogous to restricting the use of trastuzumab to breast cancers expressing the Her-2 receptor. Advances in treating primary malignant brain tumors will likely depend on collaborative clinical trials that are designed to select patients on the basis of histologic and molecular characteristics and to determine the optimal biologic dose of the best agent that can treat each specific tumor type.

The treatment of elderly patients with high-grade gliomas

Elderly patients with cancer are frequently excluded from cancer therapy trials, treated suboptimally, or not treated at all because of the widely held belief that elderly patients do not tolerate chemotherapy and/or radiotherapy (RT) as well as younger patients. Excluding elderly patients from conventional treatment, chemotherapy in particular, is often based on ad hoc decisions rather than on sound scientific data. Malignant gliomas are the most common primary brain tumors in adults, and the age-adjusted incidence of high-grade gliomas has increased over recent years, especially in the elderly. However, few investigators focus on the treatment of high-grade gliomas in the elderly. Data from retrospective studies and meta-analyses suggest that elderly patients with high-grade gliomas have a poorer outcome than younger patients, possibly because of the presence of comorbidity, resistance to cancer therapy, genetic aberrations, different histology, neurodegeneration, or age discrimination. The optimal treatment of elderly patients with high-grade gliomas has not been determined. Surgical debulking and postoperative RT are associated with a significant increase in survival among elderly patients who are in good clinical condition. A recent report has shown that treatment with temozolomide (Temodar [US], Temodal [international]; Schering-Plough Corporation, Kenilworth, NJ) plus RT provides a significant survival benefit compared with RT alone and a significantly improved time to progression compared with RT plus standard chemotherapy (lomustine, procarbazine, and vincristine). Further, temozolomide was well tolerated in the elderly patient population and was less toxic than standard chemotherapy. Therefore, it could be recommended that a full course of RT be followed by adjuvant temozolomide in elderly patients with good prognostic factors. Further, temozolomide alone could be considered as a treatment option for elderly patients with glioblastoma with poorer performance status and for patients who cannot tolerate RT. Results from larger prospective trials will determine the optimal role of chemotherapy, particularly temozolomide, in elderly patients with malignant gliomas.

Role of resection for newly diagnosed malignant gliomas

The surgical neuro-oncology literature testifies to the longstanding argument about the benefits (or lack thereof) of aggressive debulking of high-grade gliomas. Publications from the last decade addressing this question will be reviewed. The absence of randomized clinical trials and paucity of prospectively collected information continue to leave this issue unresolved, although most evidence continues to support a modest benefit of debulking over biopsy.