MGMT function determines the differential response of ATR inhibitors with DNA-damaging agents in glioma stem cells for GBM therapy.

Background: The most prevalent cancer treatments cause cell death through DNA damage. However, DNA damage response (DDR) repair pathways, initiated by tumor cells, can withstand the effects of anticancer drugs, providing justification for combining DDR inhibitors with DNA-damaging anticancer treatments. Methods: Cell viability assays were performed with CellTiter-Glo assay. DNA damage was evaluated using Western blotting analysis. RNA-seq and single-cell level expression were used to identify the DDR signatures. In vivo, studies were conducted in mice to determine the effect of ATris on TMZ sensitization. Results: We found a subpopulation of glioma sphere-forming cells (GSCs) with substantial synergism with temozolomide (TMZ) using a panel of 3 clinical-grade ataxia-telangiectasia- and Rad3-related kinase inhibitors (ATRis), (elimusertib, berzosertib, and ceralasertib). Interestingly, most synergistic cell lines had O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, indicating that ATRi mainly benefits tumors with no MGMT repair. Further, TMZ activated the ATR-checkpoint kinase 1 (Chk1) axis in an MGMT-dependent way. TMZ caused ATR-dependent Chk1 phosphorylation and DNA double-strand breaks as shown by increased γH2AX. Increased DNA damage and decreased Chk1 phosphorylation were observed upon the addition of ATRis to TMZ in MGMT-methylated (MGMT-) GSCs. TMZ also improved sensitivity to ATRis in vivo, as shown by increased mouse survival with the TMZ and ATRi combination treatment. Conclusions: This research provides a rationale for selectively targeting MGMT-methylated cells using ATRis and TMZ combination. Overall, we believe that MGMT methylation status in GBM could serve as a robust biomarker for patient selection for ATRi combined with TMZ.

Phase I trial of aflibercept (VEGF trap) with radiation therapy and concomitant and adjuvant temozolomide in patients with high-grade gliomas.

Anti-vascular endothelial growth factor (VEGF) therapy has shown promise in the treatment of high-grade gliomas (HGG). Aflibercept is a recombinant human fusion protein that acts as a soluble decoy receptor for VEGF-A, VEGF-B and placental growth factor, depleting circulating levels of these growth factors. The Adult Brain Tumor Consortium conducted a phase I trial of aflibercept and temozolomide (TMZ) in patients with newly diagnosed HGG with 2 dose levels and a 3+3 design. Three arms using aflibercept were examined; with radiation and concomitant temozolomide; with adjuvant temozolomide using the 5/28 regimen; and with adjuvant temozolomide using the 21/28 day regimen. Fifty-nine patients were enrolled, 21 in arm 1, 20 in arm 2 and 18 in arm 3. Median age was 56 years (24-69); median KPS 90 (60-100). The maximum tolerated dose (MTD) of aflibercept for all 3 arms was 4 mg/kg every 2 weeks. Dose limiting toxicities at the MTD were: Arm 1: 0/21 patients; Arm 2: 2/20 patients (G3 deep vein thrombosis, G4 neutropenia; Arm 3: 3/18 patients) (G4 biopsy-confirmed thrombotic microangiopathy, G3 rash, G4 thrombocytopenia). The median number of cycles of aflibercept was 5 (range, 1-16). All patients stopped treatment; 28 (47%) for disease progression, 21 (36%) for toxicities, 8 (14%) for other reasons, and 2 (3%) patients completed the full treatment course. This study met its primary endpoint and the MTD of aflibercept with radiation and concomitant and adjuvant temozolomide is 4 mg/kg every 2 weeks.

Leptomeningeal dissemination in glioblastoma; an inspection of risk factors, treatment, and outcomes at a single institution.

There are few studies reporting the incidence of leptomeningeal dissemination (LMD) in patients with glioblastoma; only small case series have been published. Consequently, there are no established standards of care for these patients. Therefore, we undertook this retrospective review to evaluate a large series of patients with glioblastoma treated at MD Anderson Cancer Center to estimate the incidence of LMD and assess the impact of a variety of treatment modalities. Analysis was performed on 595 patients with glioblastoma treated on clinical trials from 2006 to 2012. The diagnosis of LMD was made by imaging or positive cerebrospinal fluid cytology in 24 patients. An additional 12 patients with known LMD diagnosed during this same period were included to evaluate the impact of treatment on outcome for a total of 36 patients. LMD developed in 4.0 % (24/595 patients) of the clinical trial cohort. Median survival from glioblastoma diagnosis was 16.0 months. Estimated median time of glioblastoma diagnosis to LMD was 11.9 months. Median overall survival from the time of LMD diagnosis was 3.5 months. Patients treated for LMD with chemotherapy/targeted therapy and radiation had a significantly prolonged survival (7.7 months) compared to chemotherapy/targeted therapy alone, radiation alone or palliative care. LMD remains an uncommon event in patients with glioblastoma. Patients treated aggressively with chemotherapy/targeted therapy and radiation had the longest median survival following diagnosis of LMD. However, patients receiving chemotherapy/targeted therapy and radiation were younger and this may have influenced survival. Given the overall poor outcomes, improved therapeutic approaches are needed for glioblastoma patients with LMD.

Outcomes for patients with anaplastic astrocytoma treated with chemoradiation, radiation therapy alone or radiation therapy followed by chemotherapy: a retrospective review within the era of temozolomide.

Treatment for anaplastic astrocytoma (AA) is controversial. To assess three primary treatment approaches, patients from a single institution were retrospectively evaluated. To represent modern treatment selection, patients diagnosed with AA from December 2003 to December 2009 were selected. Those with insufficient data, incomplete pathology, and transformation or reclassification to glioblastoma in fewer than 6 months were excluded. A total of 163 patients were included in the final analyses. Median follow-up time was 4.2 years (range 0.5-7.8 years). Median age and Karnofsky performance status at diagnosis were 39.2 years and 90, respectively. 23.6 % of patients underwent biopsy, and 72.2 % underwent resection. Approximately 31 % received concurrent chemoradiation (CRT), 26.1 % had radiation therapy alone (RT), 38.2 % had radiation therapy followed by chemotherapy (RT-C), and 3 % were treated only with chemotherapy. Temozolomide was used almost exclusively during CRT (94.2 %) and adjuvantly. A median of 9.5 cycles of adjuvant chemotherapy was given. The combination of radiation and chemotherapy, either concurrent or sequential trended toward a higher rate of radiation necrosis. Median progression free survival (PFS) favored RT (not reached) over CRT (1.5 years) and RT-C (3.6 years) adjusted for pairwise comparison (p = 0.033, p = 0.050). Median overall survival (OS) was 5.7 years, and did not differ significantly by treatment group. OS for patients with AA did not vary by initial treatment selection. Although the longer PFS in those receiving RT versus CRT may be confounded by pseudoprogression, the equivalent OS among groups supports RT.

Degos' syndrome complicated by bowel perforation: focus on radiological findings.

We describe a 50-year-old man who first presented with multiple skin lesions which were characteristic of Degos' syndrome. The patient developed multiple episodes of abdominal pain. Some episodes resolved with conservative management, for others he underwent urgent operations for bowel perforations. The patient subsequently underwent extensive small bowel resection, but further systemic deterioration ensued and he died. The imaging findings of Degos' syndrome and the implications of pneumatosis intestinalis and pneumoperitoneum are discussed.

Cytokines associated with toxicity in the treatment of recurrent glioblastoma with aflibercept.

Plasma profiling of patients treated with antiangiogenic agents may identify markers that correlate with toxicity. Objectives were to correlate changes in cytokine and angiogenic factors as potential markers of toxicity to aflibercept. Circulating cytokine and angiogenic factors were measured in 28 patients with recurrent glioblastoma in a single-arm phase II study of aflibercept. Plasma samples were analyzed at baseline, 24 h, and 28 days using multiplex assays or ELISA. We evaluated log-transformed baseline biomarker expressions with Cox proportional hazard regression models to assess the effect of markers on any grade II-IV (Gr II-IV) toxicity, on-target toxicity (hypertension, proteinuria, thromboembolism), and fatigue. All tests were two sided with a statistical significance level of p = 0.05. Among 28 pts, there were 116 Gr II-IV events. Changes in IL-13 from baseline to 24 h predicted on-target toxicities. Increases in IL-1b, IL-6, and IL-10 at 24 h were significantly associated with fatigue. Progression-free survival was 14.9 months for patients in the all-toxicity group and 9.0 months for patients in the on-target toxicity group compared to 4.3 months for those who did not develop any Gr II-IV toxicity (p = 0.002 and p = 0.045, respectively). Toxicity from antiangiogenic therapy remains an important cause of antiangiogenic treatment discontinuation and patient morbidity. Changes in IL6, IL10, and IL13 were repeatedly correlated with toxicity. Profiling of IL-13 as a surrogate for endothelial dysfunction could individualize patients at risk during antiangiogenic therapy, as could identifying those at higher risk for fatigue using IL-6 and IL-10.

Medications as causes of intraluminal hyperdensities: what radiologists need to know.

In computed tomography (CT) angiogram or some dedicated CT studies of the abdomen, the use of positive enteric contrast should be avoided as its presence could decrease the sensitivity of the test. There are, however, cases of CT scans with unexpected hyperdense intraluminal contents detected due to the use of certain oral or rectal medications. Reports on medications as causes of intraluminal hyperdensities are sparse in the English literature. We have studied several commonly used medications and revealed that many drugs appear hyperdense in CT scans. The presence of unexpected intraluminal hyperdensities can potentially cause erroneous interpretation of images and in some cases decrease the sensitivity of the test. The hyperdense bowel contents may be mistaken as acute hemorrhage in CT angiogram for detection of GI bleeding. Active GI bleeding, presented as intraluminal extravasation of contrast material, can also be obscured. Certain intra-abdominal pathologies could be masked, for example, in plain CT scan for detection of urinary tract stones or in contrast CT study for suspected bowel ischaemia. It is important for radiologists and clinicians to be aware of this situation in order to prevent misinterpretation of images and to select the most appropriate imaging modality when such unexpected intraluminal hyperdensities are encountered.

Pathway inhibition: emerging molecular targets for treating glioblastoma.

Insights into the molecular pathogenesis of glioblastoma have not yet resulted in relevant clinical improvement. With standard therapy, which consists of surgical resection with concomitant temozolomide in addition to radiotherapy followed by adjuvant temozolomide, the median duration of survival is 12-14 months. Therefore, the identification of novel molecular targets and inhibitory agents has become a focus of research for glioblastoma treatment. Recent results of bevacizumab may represent a proof of principle that treatment with targeted agents can result in clinical benefits for patients with glioblastoma. This review discusses limitations in the existing therapy for glioblastoma and provides an overview of current efforts to identify molecular targets using large-scale screening of glioblastoma cell lines and tumor samples. We discuss preclinical and clinical data for several novel molecular targets, including growth factor receptors, phosphatidylinositol-3 kinase, SRC-family kinases, integrins, and CD95 ligand and agents that inhibit these targets, including erlotinib, enzastaurin, dasatinib, sorafenib, cilengitide, AMG102, and APG101. By combining advances in tumor screening with novel targeted therapies, it is hoped that new treatment options will emerge for this challenging tumor type.

Establishment of prognostic models for astrocytic and oligodendroglial brain tumors with standardized quantification of marker gene expression and clinical variables.

BACKGROUND: Prognosis models established using multiple molecular markers in cancer along with clinical variables should enable prediction of natural disease progression and residual risk faced by patients. In this study, multivariate Cox proportional hazards analyses were done based on overall survival (OS) of 100 glioblastoma multiformes (GBMs, 92 events), 49 anaplastic astrocytomas (AAs, 33 events), 45 gliomas with oligodendroglial features, including anaplastic oligodendroglioma (AO, 13 events) and oligodendraglioma (O, 9 events). The modeling included two clinical variables (patient age and recurrence at the time of sample collection) and the expression variables of 13 genes selected based on their proven biological and/or prognosis functions in gliomas (ABCG2, BMI1, MELK, MSI1, PROM1, CDK4, EGFR, MMP2, VEGFA, PAX6, PTEN, RPS9, and IGFBP2). Gene expression data was a log-transformed ratio of marker and reference (ACTB) mRNA levels quantified using absolute real-time qRT-PCR. RESULTS: Age is positively associated with overall grade (4 for GBM, 3 for AA, 2_1 for AO_O), but lacks significant prognostic value in each grade. Recurrence is an unfavorable prognostic factor for AA, but lacks significant prognostic values for GBM and AO_O. Univariate models revealed opposing prognostic effects of ABCG2, MELK, BMI1, PROM1, IGFBP2, PAX6, RPS9, and MSI1 expressions for astrocytic (GBM and AA) and oligodendroglial tumors (AO_O). Multivariate models revealed independent prognostic values for the expressions of MSI1 (unfavorable) in GBM, CDK4 (unfavorable) and MMP2 (favorable) in AA, while IGFBP2 and MELK (unfavorable) in AO_O. With all 13 genes and 2 clinical variables, the model R(2) was 14.2% (P = 0.358) for GBM, 45.2% (P = 0.029) for AA, and 62.2% (P = 0.008) for AO_O. CONCLUSION: The study signifies the challenge in establishing a significant prognosis model for GBM. Our success in establishing prognosis models for AA and AO_O was largely based on identification of a set of genes with independent prognostic values and application of standardized gene expression quantification to allow formation of a large cohort in analysis.

Imaging response in malignant glioma, RTOG 90-06.

OBJECTIVE: The purpose of this study was to determine if radiographic response correlates with survival for patients treated patients with malignant gliomas treated on Radiation Therapy Oncology Group (RTOG) protocol 90-06. This study compared patients treated with hyperfractionated radiation and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) to standard fractionation and BCNU. METHODS: There were 453 patients evaluable. Histology included anaplastic astrocytoma (60) (AA), and glioblastoma multiforme (312) (GBM). All scans were forwarded to the RTOG central office and evaluated by a single reviewer without knowledge of outcome. Response at 4 months post initiation of therapy was evaluated by computed tomography or magnetic resonance image and compared with overall survival. RESULTS: For patients with no tumor on the 4 month scan the median survival was 20.3 months and the 2 year survival 43%. Patients with partial or minor response had a median survival of 18.1 and 14.2 months and 2 year survival of 37% and 29%. Patients with progression had a median survival of 8.6 months and 2 year survival of 10%. CONCLUSIONS: Response rates were similar in both arms.

Complementary and alternative medicine use and quality of life in patients with primary brain tumors.

This study explored the use of complementary and alternative medicine (CAM) approaches and their relationship with demographic and disease characteristics and quality of life (QOL) in the primary brain tumor (PBT) population. One hundred one PBT patients were enrolled in this study. The results showed that 34% of patients reported using CAM. Forty-one percent reported using more than one type of CAM. The average cost of each CAM used per month was 69 dollars, with 20% of patients spending more than 100 dollars per month. The majority (74%) reported that their physicians were unaware of their use of CAM. Data analysis found a higher performance status to be the only factor significantly related to use of CAM therapy (P < 0.005). There was no difference in patient report of QOL between users and nonusers of CAM therapies. The high number of patients who do not report CAM use has potential implications for evaluation of symptoms and response to therapy in this population. This may be especially relevant in those patients with higher functional status participating in clinical trials.

Phase I trial of tipifarnib in patients with recurrent malignant glioma taking enzyme-inducing antiepileptic drugs: a North American Brain Tumor Consortium Study.

PURPOSE: To determine the maximum-tolerated dose (MTD), toxicities, and clinical effect of tipifarnib, a farnesyltransferase (FTase) inhibitor, in patients with recurrent malignant glioma taking enzyme-inducing antiepileptic drugs (EIAEDs). This study compares the pharmacokinetics and pharmacodynamics of tipifarnib at MTD in patients on and off EIAEDs. PATIENTS AND METHODS: Recurrent malignant glioma patients were treated with tipifarnib using an interpatient dose-escalation scheme. Pharmacokinetics and pharmacodynamics were assessed. RESULTS: Twenty-three assessable patients taking EIAEDs received tipifarnib in escalating doses from 300 to 700 mg bid for 21 of 28 days. The dose-limiting toxicity was rash, and the MTD was 600 mg bid. There were significant differences in pharmacokinetic parameters at 300 mg bid between patients on and not on EIAEDs. When patients on EIAEDs and not on EIAEDs were treated at MTD (600 and 300 mg bid, respectively), the area under the plasma concentration-time curve (AUC)(0-12 hours) was approximately two-fold lower in patients on EIAEDs. Farnesyltransferase inhibition was noted at all tipifarnib dose levels, as measured in peripheral-blood mononuclear cells (PBMC). CONCLUSION: Toxicities and pharmacokinetics differ significantly when comparing patients on or off EIAEDs. EIAEDs significantly decreased the maximum concentration, AUC(0-12 hours), and predose trough concentrations of tipifarnib. Even in the presence of EIAEDs, the levels of tipifarnib were still sufficient to potently inhibit FTase activity in patient PBMCs. The relevance of these important findings to clinical activity will be determined in ongoing studies with larger numbers of patients.

Benefit of temozolomide compared to procarbazine in treatment of glioblastoma multiforme at first relapse: effect on neurological functioning, performance status, and health related quality of life.

Since high-grade malignant gliomas can seldom be treated curatively, the main aim of first line therapy is to improve progression free survival (PFS), to reduce morbidity, and to preserve, if not restore neurological functions and the capacity to perform daily activities. Focusing on a single clinical efficacy parameter in clinical trials may provide a potentially biased result, as for patients the overall result of treatment entails a more complex picture of weighing and balancing gains and losses on different outcome measures. In this paper we address different clinical outcomes measures separately and we illustrate the value of multiple outcome measures using the results of a recent clinical trial comparing temozolomide with procarbazine in the treatment of Glioblastoma Multiforme. Compared with procarbazine, temozolomide not only prolonged PFS, but also maintained neurological functioning and performance status for a longer period of time, and also improved health-related quality of life (HRQL). All these statistically significant outcomes demonstrate a remarkable consistency. In addition, temozolomide showed a trend of extending overall survival over procarbazine.

Glutathione S-transferase polymorphisms and survival in primary malignant glioma.

PURPOSE: The purpose of this research was to investigate the relationship between glutathione S-transferase (GST) polymorphisms and survival, and chemotherapy-related toxicity in 278 glioma patients. EXPERIMENTAL DESIGN: We determined genetic variants for GSTM1, GSTT1, and GSTP1 enzymes by PCR and restriction fragment length polymorphisms. We conducted Kaplan-Meier and Cox-proportional hazard analyses to examine whether the GST polymorphisms are related to overall survival, and logistic regression analysis to explore whether the GST polymorphisms are associated with toxicity. RESULTS: For patients with anaplastic astrocytoma, anaplastic oligodendroglioma, anaplastic oligoastrocytoma, and anaplastic ependymoma (n = 78), patients with GSTP1*A/*A-M1 null genotype survived longer than did the rest of the group (median survival "not achieved," and 41 months, respectively; P = 0.06). Among patients treated with nitrosoureas (n = 108), those with GSTP1*A/*A and GSTM1 null genotype were 5.7 times (95% confidence interval, 0.9-37.4) more likely to experience an adverse event secondary to chemotherapy, compared with the others. CONCLUSIONS: In patients with anaplastic astrocytoma, anaplastic oligodendroglioma, and anaplastic oligoastrocytoma, combination of germ-line GSTP1*A/*A and GSTM1 null genotype confers a survival advantage. Patients with this genotype also have an increased risk of adverse events secondary to chemotherapy that primarily comprised nitrosourea alkylating agents.