Survival and low-grade glioma: the emergence of genetic information.

Significant gaps exist in our understanding of the causes and clinical management of glioma. One of the biggest gaps is how best to manage low-grade (World Health Organization [WHO] Grade II) glioma. Low-grade glioma (LGG) is a uniformly fatal disease of young adults (mean age 41 years), with survival averaging approximately 7 years. Although LGG patients have better survival than patients with high-grade (WHO Grade III or IV) glioma, all LGGs eventually progress to high-grade glioma and death. Data from the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute suggest that for the majority of LGG patients, overall survival has not significantly improved over the past 3 decades, highlighting the need for intensified study of this tumor. Recently published research suggests that historically used clinical variables are not sufficient (and are likely inferior) prognostic and predictive indicators relative to information provided by recently discovered tumor markers (e.g., 1p/19q deletion and IDH1 or IDH2 mutation status), tumor expression profiles (e.g., the proneural profile) and/or constitutive genotype (e.g., rs55705857 on 8q24.21). Discovery of such tumor and constitutive variation may identify variables needed to improve randomization in clinical trials as well as identify patients more sensitive to current treatments and targets for improved treatment in the future. This article reports on survival trends for patients diagnosed with LGG within the United States from 1973 through 2011 and reviews the emerging role of tumor and constitutive genetics in refining risk stratification, defining targeted therapy, and improving survival for this group of relatively young patients.

Molecular features assisting in diagnosis, surgery, and treatment decision making in low-grade gliomas.

The preferred management of suspected low-grade gliomas (LGGs) has been disputed, and the implications of molecular changes for medical and surgical management of LGGs are important to consider. Current strategies that make use of molecular markers and imaging techniques and therapeutic considerations offer additional options for management of LGGs. Mutations in the isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) genes suggest a role for this abnormal metabolic pathway in the pathogenesis and progression of these primary brain tumors. Use of magnetic resonance spectroscopy can provide preoperative detection of IDH-mutated gliomas and affect surgical planning. In addition, IDH1 and IDH2 mutation status may have an effect on surgical resectability of gliomas. The IDH-mutated tumors exhibit better prognosis throughout every grade of glioma, and mutation may be an early genetic event, preceding lineage-specific secondary and tertiary alterations that transform LGGs into secondary glioblastomas. The O6-methylguanine-DNAmethyltransferase (MGMT) promoter methylation and 1p19q codeletion status can predict sensitivity to chemotherapy and radiation in low- and intermediate-grade gliomas. Thus, these recent advances, which have led to a better understanding of how molecular, genetic, and epigenetic alterations influence the pathogenicity of the different histological grades of gliomas, can lead to better prognostication and may lead to specific targeted surgical interventions and medical therapies.

Long-term therapy with temozolomide is a feasible option for newly diagnosed glioblastoma: a single-institution experience with as many as 101 temozolomide cycles.

OBJECT: The objective of this study was to report the authors' experience with the long-term administration of temozolomide (TMZ; > 6 cycles, up to 101) in patients with newly diagnosed glioblastoma and to analyze its feasibility and safety as well as its impact on survival. The authors also compared data obtained from the group of patients undergoing long-term TMZ treatment with data from patients treated with a standard TMZ protocol. METHODS: A retrospective analysis was conducted of 37 patients who underwent operations for glioblastoma between 2004 and 2012. Volumetric analysis of postoperative Gd-enhanced MR images, obtained within 48 hours, confirmed tumor gross-total resection (GTR) in all but 2 patients. All patients received the first cycle of TMZ at a dosage of 150 mg/m(2) starting on the second or third postsurgical day. Afterward, patients received concomitant radiochemotherapy according to the Stupp protocol. With regard to adjuvant TMZ therapy, the 19 patients in Group A, aged 30-72 years (mean 56.1 years), received 150 mg/m(2) for 5 days every 28 days for more than 6 cycles (range 7-101 cycles). The 18 patients in Group B, aged 46-82 years (mean 64.8 years), received the same dose, but for no more than 6 cycles. O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status was analyzed for both groups and correlated with overall survival (OS) and progression-free survival (PFS). The impact of age, sex, Karnofsky Performance Scale score, and Ki 67 staining were also considered. RESULTS: All patients but 1 in Group A survived at least 18 months (range 18-101 months), and patients in Group B survived no more than 17 months (range 2-17 months). The long-term survivors (Group A), defined as patients who survived at least 12 months after diagnosis, were 51.3% of the total (19/37). Kaplan-Meier curve analysis showed that patients treated with more than 6 TMZ cycles had OS and PFS that was significantly longer than patients receiving standard treatment (median OS 28 months vs 8 months, respectively; p = 0.0001; median PFS 20 months vs 4 months, respectively; p = 0.0002). By univariate and multivariate Cox proportional hazard regression analysis, MGMT methylation status and number of TMZ cycles appeared to be survival prognostic factors in patients with glioblastoma. After controlling for MGMT status, highly significant differences related to OS and PFS between patients with standard and long-term TMZ treatment were still detected. Furthermore, in Group A and B, the statistical correlation of MGMT status to the number of TMZ cycles showed a significant difference only in Group A patients, suggesting that MGMT promoter methylation was predictive of response for long-term TMZ treatment. Prolonged therapy did not confer hematological toxicity or opportunistic infections in either patient group. CONCLUSIONS: This study describes the longest experience so far reported with TMZ in patients with newly diagnosed glioblastomas, with as many as 101 cycles, who were treated using GTR. Statistically significant data confirm that median survival correlates with MGMT promoter methylation status as well as with the number of TMZ cycles administered. Long-term TMZ therapy appears feasible and safe.

Intraoperative MRI for newly diagnosed supratentorial glioblastoma: a multicenter-registry comparative study to conventional surgery.

OBJECTIVE: Intraoperative MRI (iMRI) is used in the surgical treatment of glioblastoma, with uncertain effects on outcomes. The authors evaluated the impact of iMRI on extent of resection (EOR) and overall survival (OS) while controlling for other known and suspected predictors. METHODS: A multicenter retrospective cohort of 640 adult patients with newly diagnosed supratentorial glioblastoma who underwent resection was evaluated. iMRI was performed in 332/640 cases (51.9%). Reviews of MRI features and tumor volumetric analysis were performed on a subsample of cases (n = 286; 110 non-iMRI, 176 iMRI) from a single institution. RESULTS: The median age was 60.0 years (mean 58.5 years, range 20.5-86.3 years). The median OS was 17.0 months (95% CI 15.6-18.4 months). Gross-total resection (GTR) was achieved in 403/640 cases (63.0%). Kaplan-Meier analysis of 286 cases with volumetric analysis for EOR (grouped into 100%, 95%-99%, 80%-94%, and 50%-79%) showed longer OS for 100% EOR compared to all other groups (p < 0.01). Additional resection after iMRI was performed in 104/122 cases (85.2%) with initial subtotal resection (STR), leading to a 6.3% mean increase in EOR and a 2.2-cm3 mean decrease in tumor volume. For iMRI cases with volumetric analysis, the GTR rate increased from 54/176 (30.7%) on iMRI to 126/176 (71.5%) postoperatively. The EOR was significantly higher in the iMRI group for intended GTR and STR groups (p = 0.02 and p < 0.01, respectively). Predictors of GTR on multivariate logistic regression included iMRI use and intended GTR. Predictors of shorter OS on multivariate Cox regression included older age, STR, isocitrate dehydrogenase 1 (IDH1) wild type, no O6-methylguanine DNA methyltransferase (MGMT) methylation, and no Stupp therapy. iMRI was a significant predictor of OS on univariate (HR 0.82, 95% CI 0.69-0.98; p = 0.03) but not multivariate analyses. Use of iMRI was not associated with an increased rate of new permanent neurological deficits. CONCLUSIONS: GTR increased OS for patients with newly diagnosed glioblastoma after adjusting for other prognostic factors. iMRI increased EOR and GTR rate and was a significant predictor of GTR on multivariate analysis; however, iMRI was not an independent predictor of OS. Additional supporting evidence is needed to determine the clinical benefit of iMRI in the management of glioblastoma.

Patterns of care and outcomes in gliosarcoma: an analysis of the National Cancer Database.

OBJECTIVE The authors compared presenting characteristics and survival for patients with gliosarcoma (GS) and glioblastoma (GBM). Additionally, they performed a survival analysis for patients who underwent GS treatments with the hypothesis that trimodality therapy (surgery followed by radiation and chemotherapy) would be superior to nontrimodality therapy (surgery alone or surgery followed by chemotherapy or radiation). METHODS Adults diagnosed with GS and GBM between the years 2004 and 2013 were queried from the National Cancer Database. Chi-square analysis was used to compare presenting characteristics. Kaplan-Meier, Cox regression, and propensity score analyses were employed for survival analyses. RESULTS In total, data from 1102 patients with GS and 36,658 patients with GBM were analyzed. Gliosarcoma had an increased rate of gross-total resection (GTR) compared with GBM (19% vs 15%, p < 0.001). Survival was not different for patients with GBM (p = 0.068) compared with those with GS. After propensity score analysis for GS, patients receiving trimodality therapy (surgery followed by radiation and chemotherapy) had improved survival (12.9 months) compared with those not receiving trimodality therapy (5.5 months). In multivariate analysis, GTR, female sex, fewer comorbidities, trimodality therapy, and age < 65 years were associated with improved survival. There was a trend toward improved survival with MGMT promoter methylation (p = 0.117). CONCLUSIONS In this large registry study, there was no difference in survival in patients with GBM compared with GS. Among GS patients, trimodality therapy significantly improved survival compared with nontrimodality therapy. Gross-total resection also improved survival, and there was a trend toward increased survival with MGMT promoter methylation in GS. The major potential confounder in this study is that patients with poor functional status may not have received aggressive radiation or chemotherapy treatments, leading to the observed outcome. This study should be considered hypothesis-generating; however, due to its rarity, conducting a clinical trial with GS patients alone may prove difficult.

Prognostic implications of the subcellular localization of survivin in glioblastomas treated with radiotherapy plus concomitant and adjuvant temozolomide.

OBJECTIVE Currently, the standard treatment protocol for patients with newly diagnosed glioblastoma (GBM) includes surgery, radiotherapy, and concomitant and adjuvant temozolomide (TMZ). Various prognostic biomarkers for GBM have been described, including survivin expression. The aim of this study was to determine whether the subcellular localization of survivin correlates with GBM prognosis in patients who received the standard treatment protocol. METHODS The authors retrospectively examined the subcellular localization of survivin (nuclear, cytoplasmic, or both) using immunohistochemistry in 50 patients with GBM who had received the standard treatment. The relationship between survivin localization and overall survival (OS) was assessed with uni- and multivariate analyses including other clinicopathological factors (age, sex, Karnofsky Performance Scale [KPS] score, extent of resection, the use of second-line bevacizumab, O6-methylguanine-DNA methyltransferase [MGMT] status, and MIB-1 labeling index). RESULTS Log-rank tests revealed that patient age, KPS score, extent of resection, MGMT status, and survivin localization (p < 0.0001) significantly correlated with OS. Multivariate analysis indicated that patient age, MGMT status, and survivin localization significantly correlated with OS. Patients with nuclear localization of survivin had a significantly shorter OS than those in whom survivin expression was exclusively cytoplasmic (median OS 19.5 vs 31.7 months, respectively, HR 5.690, 95% CI 2.068-17.612, p = 0.0006). There was no significant difference in OS between patents whose survivin expression was exclusively nuclear or nuclear/cytoplasmic. CONCLUSIONS Nuclear expression of survivin is a factor for a poor prognosis in GBM patients. Subcellular localization of survivin can help to predict OS in GBM patients treated with the standard protocol.

Role of photodynamic therapy using talaporfin sodium and a semiconductor laser in patients with newly diagnosed glioblastoma.

OBJECTIVE: In this study on the effectiveness and safety of photodynamic therapy (PDT) using talaporfin sodium and a semiconductor laser, the long-term follow-up results of 11 patients with glioblastoma enrolled in the authors' previous phase II clinical trial (March 2009-2012) and the clinical results of 19 consecutive patients with newly diagnosed glioblastoma prospectively enrolled in a postmarket surveillance (March 2014-December 2016) were analyzed and compared with those of 164 patients treated without PDT during the same period. METHODS: The main outcome measures were the median overall survival (OS) and progression-free survival (PFS) times. Moreover, the adverse events and radiological changes after PDT, as well as the patterns of recurrence, were analyzed and compared between the groups. Kaplan-Meier curves were created to assess the differences in OS and PFS between the groups. Univariate and multivariate analyses were performed to identify the prognostic factors, including PDT, among patients with newly diagnosed glioblastoma. RESULTS: The median PFS times of the PDT and control groups were 19.6 and 9.0 months, with 6-month PFS rates of 86.3% and 64.9%, respectively (p = 0.016). The median OS times were 27.4 and 22.1 months, with 1-year OS rates of 95.7% and 72.5%, respectively (p = 0.0327). Multivariate analyses found PDT, preoperative Karnofsky Performance Scale score, and IDH mutation to be significant independent prognostic factors for both OS and PFS. Eighteen of 30 patients in the PDT group experienced tumor recurrence, including local recurrence, distant recurrence, and dissemination in 10, 3, and 4 patients, respectively. Conversely, 141 of 164 patients in the control group experienced tumor recurrence, including 101 cases of local recurrence. The rate of local recurrence tended to be lower in the PDT group (p = 0.06). CONCLUSIONS: The results of the present study suggest that PDT with talaporfin sodium and a semiconductor laser provides excellent local control, with few adverse effects even in cases of multiple laser irradiations, as well as potential survival benefits for patients with newly diagnosed glioblastoma.

Outcomes and prognostic stratification of patients with recurrent glioblastoma treated with salvage stereotactic radiosurgery.

OBJECTIVE: Glioblastoma (GBM) is the most malignant form of astrocytoma. The average survival is 6-10 months in patients with recurrent GBM (rGBM). In this study, the authors evaluated the role of stereotactic radiosurgery (SRS) in patients with rGBMs. METHODS: The authors performed a retrospective review of their brain tumor database (1997-2016). Overall survival (OS) and progression-free survival (PFS) after salvage SRS were the primary endpoints evaluated. Response to SRS was assessed using volumetric MR images. RESULTS: Fifty-three patients with rGBM underwent salvage SRS targeting 75 lesions. The median tumor diameter and volume were 2.55 cm and 3.80 cm3, respectively. The median prescription dose was 18 Gy (range 12-24 Gy) and the homogeneity index was 1.90 (range 1.11-2.02). The median OS after salvage SRS was estimated to be 11.0 months (95% CI 7.1-12.2) and the median PFS after salvage SRS was 4.4 months (95% CI 3.7-5.0). A Karnofsky Performance Scale score ≥ 80 was independently associated with longer OS, while small tumor volume (< 15 cm3) and less homogeneous treatment plans (homogeneity index > 1.75) were both independently associated with longer OS (p = 0.007 and 0.03) and PFS (p = 0.01 and 0.002, respectively). Based on these factors, 2 prognostic groups were identified for PFS (5.4 vs 3.2 months), while 3 were identified for OS (median OS of 15.2 vs 10.5 vs 5.2 months). CONCLUSIONS: SRS is associated with longer OS and/or PFS in patients with good performance status, small-volume tumor recurrences, and heterogeneous treatment plans. The authors propose a prognostic model to identify a cohort of rGBM patients who may benefit from SRS.

MGMT promoter methylation in patients with glioblastoma: is methylation-sensitive high-resolution melting superior to methylation-sensitive polymerase chain reaction assay?

OBJECTIVE: The methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) gene promoter is a prognostic factor in adults with glioblastoma (GBM); it also yields information that is useful for clinical decision-making in elderly GBM patients. While pyrosequencing is the gold standard for the evaluation of the methylation status of MGMT, methylation-sensitive polymerase chain reaction (MS-PCR) assay continues to be used widely. Although MS-PCR results exhibited a good correlation with the prognosis of patients with GBM treated under the Stupp protocol, interpretation of the bands is based on subjective judgment, and the assay cannot be used to analyze heterogeneously methylated samples. We assessed whether methylation-sensitive high-resolution melting (MS-HRM) is an alternative to MS-PCR. METHODS: The authors prepared 3 primer sets that covered CpG 72­89 for MS-HRM analysis to determine the methylation levels of 6 human glioma cell lines. The results were validated by bisulfite sequencing of cloned alleles. The authors also subjected surgical samples from 75 GBM patients treated with temozolomide (TMZ) to MS-HRM to assess the MGMT methylation status and compared the findings with MS-PCR results using receiver operating characteristic (ROC), univariate, and multivariate analyses. RESULTS: There was a strong correlation between the methylation levels of the 6 glioma cell lines evaluated by MSHRM and by bisulfite sequencing; with primers 1 and 2, the correlation was significant (r = 0.959 and r = 0.960, respectively, p < 0.01). Based on log-rank analysis, MS-HRM was significantly better than MS-PCR for predicting progressionfree survival (PFS) and overall survival (OS) based on the methylation status of the MGMT promoter (PFS predicted by MS-HRM and MS-PCR = 0.00023 and 0.0035, respectively; OS = 0.00019 and 0.00028, respectively). ROC analysis showed that the area under the curve was larger with MS-HRM than with MS-PCR (PFS: 0.723 vs 0.635; OS: 0.716 vs 0.695). Based on multivariate Cox regression analysis, MS-HRM was significantly better than MS-PCR for predicting the treatment outcome (MS-HRM vs MS-PCR: PFS, p = 0.001 vs 0.207; OS, p = 0.013 vs 0.135). CONCLUSIONS: The authors' findings show that MS-HRM is superior to MS-PCR for the detection of MGMT promoter methylation. They suggest MS-HRM as an alternative to MS-PCR for assessing the prognosis of patients with GBM.

Survival effects of a strategy favoring second-line multimodal treatment compared to supportive care in glioblastoma patients at first progression.

OBJECTIVEData on the survival effects of supportive care compared to second-line multimodal treatment for glioblastoma progression are scarce. Thus, the authors assessed survival in two population-based, similar cohorts from two European university hospitals with different treatment strategies at first progression.METHODSThe authors retrospectively identified patients with newly diagnosed glioblastoma treated at two neurooncological centers. After diagnosis, patients from both centers received identical treatments, but at tumor progression each center used a different approach. In the majority of cases, at center A (Greece), supportive care or a single therapeutic modality was offered at progression, whereas center B (Germany) provided multimodal second-line therapy. The main outcome measure was survival after progression (SaP). The influence of the treatment strategy on SaP was assessed by multivariate analysis.RESULTSOne hundred three patients from center A and 156 from center B were included. Tumor progression was observed in 86 patients (center A) and 136 patients (center B). At center A, 53 patients (72.6%) received supportive care alone, while at center B, 91 patients (80.5%) received second-line treatment. Progression-free survival at both centers was similar (9.4 months [center A] vs 9.0 months [center B]; p = 0.97), but SaP was significantly improved in the patients treated with multimodal second-line therapy at center B (7 months, 95% CI 5.3-8.7 months) compared to those treated with supportive care or a single therapeutic modality at center A (4.5 months, 95% CI 3.5-5.5 months; p = 0.003). In the multivariate analysis, the treatment center was an independent prognostic factor for overall survival (HR 1.59, 95% CI 0.17-2.15; p = 0.002).CONCLUSIONSTreatment strategy favoring multimodal second-line treatment over minimal treatment or supportive care at glioblastoma progression is associated with significantly better overall survival.

Ventricle contact is associated with lower survival and increased peritumoral perfusion in glioblastoma.

OBJECTIVE: The purpose of this study was to prospectively investigate outcome and differences in peritumoral MRI characteristics of glioblastomas (GBMs) that were in contact with the ventricles (ventricle-contacting tumors) and those that were not (noncontacting tumors). GBMs are heterogeneous tumors with variable survival. Lower survival is suggested for patients with ventricle-contacting tumors than for those with noncontacting tumors. This might be supported by aggressive peritumoral MRI features. However, differences in MRI characteristics of the peritumoral environment between ventricle-contacting and noncontacting GBMs have not yet been investigated. METHODS: Patients with newly diagnosed GBM underwent preoperative MRI with contrast-enhanced T1-weighted, FLAIR, diffusion-weighted, and perfusion-weighted sequences. Tumors were categorized into ventricle-contacting or noncontacting based on contrast enhancement. Survival analysis was performed using log-rank for univariate analysis and Cox regression for multivariate analysis. Normalized perfusion (relative cerebral blood volume [rCBV]) and diffusion (apparent diffusion coefficient [ADC]) values were calculated in 2 regions: the peritumoral nonenhancing FLAIR region overlapping the subventricular zone and the remaining peritumoral nonenhancing FLAIR region. RESULTS: Overall survival was significantly lower for patients with contacting tumors than for those with noncontacting tumors (434 vs 747 days, p < 0.001). Progression-free survival showed a comparable trend (260 vs 375 days, p = 0.094). Multivariate analysis confirmed a survival difference for both overall survival (HR 3.930, 95% CI 1.740-8.875, p = 0.001) and progression-free survival (HR 2.506, 95% CI 1.254-5.007, p = 0.009). Peritumoral perfusion was higher in contacting than in noncontacting tumors for both FLAIR regions (p = 0.04). There was no difference in peritumoral ADC values between the 2 groups. CONCLUSIONS: Patients with ventricle-contacting tumors had poorer outcomes than patients with noncontacting tumors. This disadvantage of ventricle contact might be explained by higher peritumoral perfusion leading to more aggressive behavior.

The effect of postoperative infection on survival in patients with glioblastoma.

OBJECTIVE Glioblastoma is a primary glial neoplasm with a median survival of approximately 1 year. There are anecdotal reports that postoperative infection may confer a survival advantage in patients with glioblastoma. However, only a few case reports in the literature, along with 2 retrospective cohort studies, show some potential link between infection and prolonged survival in patients with glioblastoma. The objective of this study was to evaluate the effect of postoperative infection in patients with glioblastoma using a large national database. METHODS The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database was searched to identify patients 66 years of age and older with glioblastoma, with and without infection, from 1997 to 2010. The primary outcome was survival after diagnosis. The statistical analysis was performed with a graphical representation using Kaplan-Meier curves, univariate analysis with the log-rank test, and multivariate analysis with proportional hazards modeling. RESULTS A total of 3784 patients with glioblastoma were identified from the database, and from these, 369 (9.8%) had postoperative infection within 1 month of surgery. In patients with glioblastoma who had an infection within 1 month of surgery, there was no significant difference in survival (median 5 months) compared with patients with no infection (median 6 months; p = 0.17). The study also showed that older age, increased Gagne comorbidity score, and having diabetes may be negatively associated with survival. CONCLUSIONS Infection after craniotomy within 1 month was not associated with a survival benefit in patients with glioblastoma.

Increased expression of the histone H3 lysine 4 methyltransferase MLL4 and the histone H3 lysine 27 demethylase UTX prolonging the overall survival of patients with glioblastoma and a methylated MGMT promoter.

OBJECTIVE The purpose of the present study was to investigate the epigenetic and prognostic roles of an H3K4 methyltransferase (mixed lineage leukemia 4 [MLL4]) and H3K27 demethylase (ubiquitously transcribed tetratricopeptide repeat gene on X chromosome [UTX]) in progression-free survival (PFS) and overall survival (OS) of patients with glioblastoma (GBM) who were treated with radiotherapy, chemotherapy, or both after resection. In addition, the authors examined methylation at the promoter of the O-6-methylguanine-DNA methyltransferase ( MGMT) gene and other prognostic factors predicting length of PFS and OS in these patients. METHODS The medical records of 76 patients having a new diagnosis of histologically ascertained GBM in the period of January 2002 to December 2013 at the authors' institution were retrospectively reviewed. Immunohistochemical staining for MLL4 and UTX was performed on archived paraffin-embedded tissues obtained by biopsy or resection. The methylation status of the MGMT promoter in these tissues was determined by methylation-specific PCR analysis. RESULTS During the follow-up period (mean length 18.1 months, range 4.1-43.5 months), 68 (89.5%) of the patients died. The MGMT promoter was methylated in 49 patients (64.5%) and unmethylated in 27 (35.5%). The immunoreactivity pattern of UTX was identical to that of MLL4; increased expression of these 2 proteins was observed in samples from 34 patients (44.7%) and decreased expression in 42 patients (55.3%). The mean length of PFS was 9.2 months (95% CI 6.8-11.6 months). Extent of surgery, recursive partitioning analysis (RPA) class, and methylation status of the MGMT promoter were all associated with increased PFS in the multivariate analysis of factors predicting PFS. The mean length of OS was 18.6 months (95% CI 14.3-22.9 months). Patient age (p = 0.004), WHO performance status score (p = 0.019), extent of surgery (p = 0.007), RPA class (p = 0.036), methylation status of the MGMT promoter (p = 0.010), and increased expression of UTX-MLL4 (p = 0.001) were significantly associated with increased OS in multivariate analysis. Interestingly, in patients with an unmethylated MGMT promoter, immunoreactivity of UTX-MLL4 was not associated with changes in OS (p = 0.350). However, in the patients with a methylated MGMT promoter, increased UTX-MLL4 expression was strongly associated with increased OS (p < 0.001). CONCLUSIONS The results of this study suggest that increased expression of UTX-MLL4 positively influences the outcome of patients with GBM having a methylated MGMT promoter. Therefore, UTX-MLL4 immunoreactivity could be a useful predictor of the response to conventional treatment with radiotherapy or chemotherapy among GBM patients whose tumors have a methylated MGMT promoter.

ACTC1 as an invasion and prognosis marker in glioma.

OBJECTIVE Glioma is a major class of brain tumors, and glioblastoma (GBM) is the most aggressive and malignant type. The nature of tumor invasion makes surgical removal difficult, which results in remote recurrence. The present study focused on glioma invasion and investigated the expression of actin, alpha cardiac muscle 1 (ACTC1), which is 1 of 6 actin families implicated in cell motility. METHODS mRNA expression of ACTC1 expression was analyzed using quantitative real-time polymerase chain reaction (qRT-PCR) in 47 formalin-fixed, paraffin-embedded glioma tissues that were graded according to WHO criteria: Grade I (n = 4); Grade II (n = 12); Grade III (n = 6); and Grade IV (n = 25). Survival was analyzed using the Kaplan-Meier method. The relationships between ACTC1 expression and clinical features such as radiological findings at the time of diagnosis and recurrence, patient age, Karnofsky Performance Scale status (KPS), and the MIB-1 index were evaluated. RESULTS The incidence of ACTC1 expression as a qualitative assessment gradually increased according to WHO grade. The hazard ratio for the median overall survival (mOS) of the patients with ACTC1-positive high-grade gliomas as compared with the ACTC1-negative group was 2.96 (95% CI, 1.03-8.56). The mOS was 6.28 years in the ACTC1-negative group and 1.26 years in the positive group (p = 0.037). In GBM patients, the hazard ratio for mOS in the ACTC1-positive GBMs as compared with the ACTC1-negative group was 2.86 (95% CI 0.97-8.45). mOS was 3.20 years for patients with ACTC1-negative GBMs and 1.08 years for patients with ACTC1-positive GBMs (p = 0.048). By the radiological findings, 42.9% of ACTC1-positive GBM patients demonstrated invasion toward the contralateral cerebral hemisphere at the time of diagnosis, although no invasion was observed in ACTC1-negative GBM patients (p = 0.013). The recurrence rate of GBM was 87.5% in the ACTC1-positive group; in contrast, none of the ACTC1-negative patients demonstrated distant recurrence (0.007). No remarkable relationship was demonstrated among ACTC1 expression and patient age, KPS, and the MIB-1 index. CONCLUSIONS ACTC1 may serve as a novel independent prognostic and invasion marker in GBM.

Combination therapy in a xenograft model of glioblastoma: enhancement of the antitumor activity of temozolomide by an MDM2 antagonist.

OBJECTIVE Improvement in treatment outcome for patients with glioblastoma multiforme (GBM) requires a multifaceted approach due to dysregulation of numerous signaling pathways. The murine double minute 2 (MDM2) protein may fulfill this requirement because it is involved in the regulation of growth, survival, and invasion. The objective of this study was to investigate the impact of modulating MDM2 function in combination with front-line temozolomide (TMZ) therapy in GBM. METHODS The combination of TMZ with the MDM2 protein-protein interaction inhibitor nutlin3a was evaluated for effects on cell growth, p53 pathway activation, expression of DNA repair proteins, and invasive properties. In vivo efficacy was assessed in xenograft models of human GBM. RESULTS In combination, TMZ/nutlin3a was additive to synergistic in decreasing growth of wild-type p53 GBM cells. Pharmacodynamic studies demonstrated that inhibition of cell growth following exposure to TMZ/nutlin3a correlated with: 1) activation of the p53 pathway, 2) downregulation of DNA repair proteins, 3) persistence of DNA damage, and 4) decreased invasion. Pharmacokinetic studies indicated that nutlin3a was detected in human intracranial tumor xenografts. To assess therapeutic potential, efficacy studies were conducted in a xenograft model of intracranial GBM by using GBM cells derived from a recurrent wild-type p53 GBM that is highly TMZ resistant (GBM10). Three 5-day cycles of TMZ/nutlin3a resulted in a significant increase in the survival of mice with GBM10 intracranial tumors compared with single-agent therapy. CONCLUSIONS Modulation of MDM2/p53-associated signaling pathways is a novel approach for decreasing TMZ resistance in GBM. To the authors' knowledge, this is the first study in a humanized intracranial patient-derived xenograft model to demonstrate the efficacy of combining front-line TMZ therapy and an inhibitor of MDM2 protein-protein interactions.

Ultrasound-induced opening of the blood-brain barrier to enhance temozolomide and irinotecan delivery: an experimental study in rabbits.

OBJECT The blood-brain barrier (BBB) limits the intracerebral penetration of drugs and brain tumor treatment efficacy. The effect of ultrasound-induced BBB opening on the intracerebral concentration of temozolomide (TMZ) and irinotecan (CPT-11) was assessed. METHODS This study was performed using 34 healthy New Zealand rabbits. Half had unilateral BBB opening, and half served as controls. Sonications were performed by pulsing a 1.05-MHz planar ultrasound transducer with a duty cycle of 2.5% and an in situ acoustic pressure level of 0.6 MPa after injection of a microbubble ultrasound contrast agent. Drugs were injected either 5 minutes before (ChemoPreUS) or 15 minutes after (ChemoPostUS) the ultrasound sonication. The plasma and intracerebral concentrations of both drugs were quantified using ultra-performance liquid chromatography. RESULTS The mean intracerebral tissue-to-plasma drug concentration ratio in the control hemispheres was 34% for TMZ and 2% for CPT-11. After BBB opening, these values increased by up to 21% for TMZ and up to 178% for CPT-11. Intracerebral concentrations of drugs were enhanced in regions where the BBB was opened compared with the contralateral hemisphere (p < 0.01 and p < 0.0001 for CPT-11, p = 0.02 and p = 0.03 for TMZ, in ChemoPreUS and ChemoPostUS, respectively) and compared with the control group (p < 0.001 and p < 0.0001 for CPT-11, p < 0.01 and p = 0.02 for TMZ, in ChemoPreUS and ChemoPostUS, respectively). The intracerebral distribution of drugs was heterogeneous, depending on the distance from the ultrasound source. CONCLUSIONS Ultrasound-induced opening of the BBB significantly enhances the intracerebral concentration of both TMZ and CPT-11 in rabbits.

Long-term outcome of patients with WHO Grade III and IV gliomas treated by fractionated intracavitary radioimmunotherapy.

OBJECT: The aim in this study was to present long-term results regarding overall survival (OS), adverse effects, and toxicity following fractionated intracavitary radioimmunotherapy (RIT) with iodine-131- or yttrium-90-labeled anti-tenascin monoclonal antibody ((131)I-mAB or (90)Y-mAB) for the treatment of patients with malignant glioma. METHODS: In 55 patients (15 patients with WHO Grade III anaplastic astrocytoma [AA] and 40 patients with WHO Grade IV glioblastoma multiforme [GBM]) following tumor resection and conventional radiotherapy, radioimmunoconjugate was introduced into the postoperative resection cavity. Patients received 5 cycles of (90)Y-mAB (Group A, average dose 18 mCi/cycle), 5 cycles of (131)I-mAB (Group B, average dose 30 mCi/cycle), or 3 cycles of (131)I-mAB (Group C, 50, 40, and 30 mCi). RESULTS: Median OS of patients with AA was 77.2 months (95% CI 30.8 to > 120). Five AA patients (33%) are currently alive, with a median observation time of 162.2 months. Median OS of all 40 patients with GBM was 18.9 months (95% CI 15.8-25.3), and median OS was 25.3 months (95% CI18-30) forthose patients treated with the (131)I-mAB. Three GBM patients are currently alive. One-, 2-, and 3-year survival probabilities were 100%, 93.3%, and 66.7%, respectively, for AA patients and 82.5%, 42.5%, and 15.9%, respectively, for GBM patients. Restratification of GBM patients by recursive partitioning analysis (RPA) Classes III, IV, and V produced median OSs of 31.1, 18.9, and 14.5 months, respectively (p = 0.004), which was higher than expected. Multivariate analysis confirmed the role of RPA class, age, and treatment in predicting survival. No Grade 3 or 4 hematological, nephrologic, or hepatic toxic effects were observed; 4 patients developed Grade 3 neurological deficits. Radiological signs of radionecrosis were observed in 6 patients, who were all responding well to steroids. CONCLUSIONS: Median OS of GBM and AA patients treated with (131)I-mABs reached 25.3 and 77.2 months, respectively, thus markedly exceeding that of historical controls. Adverse events remained well controllable with the fractionated dosage regimen.

Correlation of high delta-like ligand 4 expression with peritumoral brain edema and its prediction of poor prognosis in patients with primary high-grade gliomas.

OBJECT: Peritumoral brain edema (PTBE) is a common phenomenon associated with high-grade gliomas (HGGs). In this study, the authors investigated the expression of Notch delta-like ligand 4 (DLL4) and its correlation with PTBE and prognosis in patients with an HGG. METHODS: Tumors from 99 patients with HGG were analyzed for DLL4 expression using immunohistochemistry. PTBE on preoperative MR images and the relationship between PTBE and DLL4 expression were evaluated. The effect of DLL4 on patient prognosis was assessed by using Kaplan-Meier survival and Cox proportional hazard models. RESULTS: Immunohistochemistry results revealed that the expression of DLL4 was distributed primarily within the cytoplasm of tumor vascular endothelial cells and seldom detected in tumor cells. DLL4 expression was correlated positively with the degree of edema (r = 0.845 and p < 0.001, Spearman's test). In addition, DLL4 was an independent predictor of prognosis in patients with HGGs (p = 0.001). CONCLUSIONS: DLL4 expression was correlated positively with the degree of PTBE and was an independent unfavorable prognostic indicator in patients with HGG.

Residual tumor volume and patient survival following reoperation for recurrent glioblastoma.

OBJECTIVES: Maximal safe tumor resection is part of the standard of care for patients with newly diagnosed glioblastoma. The role of reoperation in the care of patients with recurrent glioblastoma is less clear, and less than a quarter of patients undergo a second surgery. Previous studies have identified preoperative variables associated with the improved survival of patients following reoperation, and guidelines for the selection of patients for reoperation have been devised and validated. In this study, the authors analyzed the relative survival benefit of maximal safe tumor removal in a series of patients with recurrent glioblastoma who all underwent reoperation. METHODS: In this longitudinal study, the clinical and radiological data of 97 consecutive patients who underwent reoperation for recurrent glioblastoma were prospectively collected. Multiple regression analyses and Kaplan-Meier plotting were performed to identify pre- and postoperative clinical and radiological variables associated with increased survival following reoperation. RESULTS: The median postoperative survival of all patients following reoperation was 12.4 months (95% confidence interval [CI] 9.0-15.6 months). Multiple Cox regression analysis revealed that patients with large (> 3 cm(3)) residual tumors following reoperation had significantly decreased survival relative to those with residual tumors that were small (> 0-3 cm(3); hazard ratio [HR] = 3.10, 95% CI 1.69-5.70; p < 0.001) or radiologically absent (0 cm(3); HR = 5.82, 95% CI 2.98-11.37; p < 0.001). Large residual tumors had faster rates of subsequent regrowth than small (odds ratio [OR] = 4.22, 95% CI 1.19-14.97; p = 0.026) or radiologically absent (OR = 11.00, 95% CI 2.79-43.43; p = 0.001) residual tumors, and a faster regrowth rate was significantly associated with decreased survival (HR = 4.01, 95% CI 2.26-7.14; p < 0.001). CONCLUSIONS: The overall survival of patients with recurrent glioblastoma who underwent reoperations increased with decreasing postoperative residual tumor volumes. For patients meeting prognostic criteria for reoperation, the surgical goal should be to minimize residual tumor volume to maximize overall survival. Clinical trial registration no.: NCT00060541 ( ClinicalTrials.gov ).

Is the absolute value of O(6)-methylguanine-DNA methyltransferase gene messenger RNA a prognostic factor, and does it predict the results of treatment of glioblastoma with temozolomide?

OBJECTIVES: Methylation of O(6)-methylguanine-DNA methyltransferase (MGMT) has been reported to be a good prognostic factor for patients with glioblastoma multiforme (GBM). To determine whether the absolute value of MGMT messenger RNA (mRNA) might be a prognostic factor and useful for predicting the therapeutic effectiveness of temozolomide, especially with regard to GBMs, the authors measured the absolute value of MGMT mRNA in gliomas by using real-time reverse-transcription polymerase chain reaction (RT-PCR). METHODS: MGMT mRNA was measured in 140 newly diagnosed gliomas by real-time RT-PCR using the Taq-Man probe. Among 73 GBMs, 45 had been initially treated with temozolomide and radiation. RESULTS: The mean MGMT mRNA value was significantly lower in oligodendroglial tumors than in other tumors. In the 73 GBMs, a significant prognostic factor for progression-free survival was fewer than 1000 copies/ µgRNA of MGMT mRNA (p = 0.0150). Of 45 patients with GBMs that had been treated with temozolomide and radiation, progression-free survival was significantly longer for those whose GMB had fewer than 1000 copies/µgRNA of MGMT mRNA than for those whose GBM had more than 1000 copies/µgRNA (p = 0.0090). In 32 patients with GBMs treated by temozolomide and radiation whose age was younger than 75 years and whose Karnofsky Performance Scale score was more than 70, progression-free and overall survival times were longer for those with GBMs of fewer than 5000 copies/µgRNA of MGMT mRNA than for those with GBMs of more than 5000 copies/µgRNA (p = 0.0365 and p = 0.0312). CONCLUSIONS: MGMT mRNA might be useful as a prognostic factor and for predicting the results of therapy for GBMs treated by temozolomide. New individual adjuvant therapy based on the results of MGMT mRNA quantitation has been proposed.