[Show abstract][Hide abstract] ABSTRACT: Glioblastoma (GBM) is the most common malignant brain tumor in adults and is associated with a poor prognosis. Cytotoxic T lymphocyte antigen -4 (CTLA-4) blocking antibodies have demonstrated an ability to generate robust antitumor immune responses against a variety of solid tumors. 4-1BB (CD137) is expressed by activated T lymphocytes and served as a co-stimulatory signal, which promotes cytotoxic function. Here, we evaluate a combination immunotherapy regimen involving 4-1BB activation, CTLA-4 blockade, and focal radiation therapy in an immune-competent intracranial GBM model.
[Show abstract][Hide abstract] ABSTRACT: Extravascular optical coherence tomography (OCT), as a noninvasive imaging methodology with micrometer resolution, was evaluated in a murine model of carotid atherosclerosis by way of assessing the efficacy of pravastatin therapy.
An OCT device was engineered for extravascular plaque imaging. Wild-type mice and apolipoprotein E-deficient (ApoE(-/-)) mice were randomized to 3 treatment groups: (1) wild-type on a diet of standard rodent chow (n=13); (2) ApoE(-/-) on a high-fat, atherosclerotic diet (HFD; n=13); and (3) ApoE(-/-) on a HFD given daily pravastatin (n=13). Mice were anesthetized and the left common carotid was surgically exposed. Three-dimensional (3D; 2 spatial dimensions+time) and 4D (3 spatial dimensions+time) OCT images of the vessel lumen patency were evaluated. After perfusion, in situ OCT imaging was performed for statistical comparison with the in vivo results and final histology.
Intraoperative OCT imaging positively identified carotid plaque in 100% of ApoE(-/-) mice on HFD. ApoE(-/-) mice on HFD had a significantly decreased lumen patency when compared with that in wild-type mice (P<0.001). Pravastatin therapy was found to increase lumen patency significantly in ApoE(-/-) mice on HFD (P<0.01; compared with ApoE(-/-) on HFD). The findings were confirmed with OCT imaging after perfusion and histology.
OCT imaging offers the potential for real-time, detailed vessel lumen evaluation, potentially improving surgical accuracy and outcomes during cerebrovascular neurosurgical procedures. Pravastatin significantly increases vessel lumen patency in the ApoE(-/-) mouse on HFD.
[Show abstract][Hide abstract] ABSTRACT: Object The aim of this study was to demonstrate that paclitaxel could function as a radiosensitizer for malignant glioma in vitro and in vivo. Methods The radiosensitizing effect of paclitaxel was tested in vitro using the human U373MG and rat 9L glioma cell lines. Cell cycle arrest in response to paclitaxel exposure was quantified by flow cytometry. Cells were subsequently irradiated, and toxicity was measured using the clonogenic assay. In vivo studies were performed in Fischer 344 rats implanted with intracranial 9L gliosarcoma. Rats were treated with control polymer implants, paclitaxel controlled-release polymers, radiotherapy, or a combination of the 2 treatments. The study end point was survival. Results Flow cytometry demonstrated G2-M arrest in both U373MG and 9L cells following 6-12 hours of paclitaxel exposure. The order in which the combination treatment was administered was significant. Exposure to radiation treatment (XRT) during the 6-12 hours after paclitaxel treatment resulted in a synergistic reduction in colony formation. This effect was greater than the effect from either treatment alone and was also greater than the effect of radiation exposure followed by paclitaxel. Rats bearing 9L gliosarcoma tumors treated with paclitaxel polymer administration followed by single-fraction radiotherapy demonstrated a synergistic improvement in survival compared with any other treatment, including radiotherapy followed by paclitaxel treatment. Median survival for control animals was 13 days; for those treated with paclitaxel alone, 21 days; for those treated with XRT alone, 21 days; for those treated with XRT followed by paclitaxel, 45 days; and for those treated with paclitaxel followed by XRT, more than 150 days (p < 0.0001). Conclusions These results indicate that paclitaxel is an effective radiosensitizer for malignant gliomas because it renders glioma cells more sensitive to ionizing radiation by causing G2-M arrest, and induces a synergistic response to chemoradiotherapy.
Journal of Neurosurgery 03/2014; · 3.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The development of noninvasive methods to detect and monitor tumors continues to be a major challenge in oncology. We used digital polymerase chain reaction-based technologies to evaluate the ability of circulating tumor DNA (ctDNA) to detect tumors in 640 patients with various cancer types. We found that ctDNA was detectable in >75% of patients with advanced pancreatic, ovarian, colorectal, bladder, gastroesophageal, breast, melanoma, hepatocellular, and head and neck cancers, but in less than 50% of primary brain, renal, prostate, or thyroid cancers. In patients with localized tumors, ctDNA was detected in 73, 57, 48, and 50% of patients with colorectal cancer, gastroesophageal cancer, pancreatic cancer, and breast adenocarcinoma, respectively. ctDNA was often present in patients without detectable circulating tumor cells, suggesting that these two biomarkers are distinct entities. In a separate panel of 206 patients with metastatic colorectal cancers, we showed that the sensitivity of ctDNA for detection of clinically relevant KRAS gene mutations was 87.2% and its specificity was 99.2%. Finally, we assessed whether ctDNA could provide clues into the mechanisms underlying resistance to epidermal growth factor receptor blockade in 24 patients who objectively responded to therapy but subsequently relapsed. Twenty-three (96%) of these patients developed one or more mutations in genes involved in the mitogen-activated protein kinase pathway. Together, these data suggest that ctDNA is a broadly applicable, sensitive, and specific biomarker that can be used for a variety of clinical and research purposes in patients with multiple different types of cancer.
Science translational medicine 02/2014; 6(224):224ra24. · 10.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We present our experience in managing craniocervical junction meningiomas and discuss various surgical approaches and outcomes.
We retrospectively reviewed 22 consecutive cases of craniocervical junction meningiomas operated on between August 1995 and May 2012.
There were 15 female and 7 male patients (mean age: 54 years). Meningiomas were classified based on origin as spinocranial (7 cases) or craniospinal (15 cases). Additionally, the tumors were divided into anatomical location relative to the brainstem or spinal cord: there were 2 anterior tumors, 7 anterolateral, 12 lateral, and 1 posterolateral. Surgical approaches included the posterior midline suboccipital approach (9 cases), the far lateral approach (12 cases) and the lateral retrosigmoid approach (1 case). Gross-total resection was achieved in 45% of patients and subtotal in 55%. The most common post-operative complications were cranial nerve (CN) IX and X deficits. The mortality rate was 4.5%. There have been no recurrences to date with a mean follow-up was 46.5 months and the mean Karnofsky score at the last follow-up of 82.3. In this series, spinocranial tumors were detected at a smaller size (p=0.0724) and treated earlier (p=0.1398) than craniospinal tumors. They were associated with a higher rate of total resection (p=0.0007), fewer post-operative CN IX or X deficits (p=0.0053), and shorter hospitalizations (p=0.08).
Our experience suggests that posterior midline suboccipital or far-lateral approaches with minimal condylar drilling and vertebral artery mobilization were suitable for most cases in this series.
Clinical neurology and neurosurgery 02/2014; 117C:71-79. · 1.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Object The poor outcome of malignant gliomas is largely due to local invasiveness. Previous studies suggest that gliomas secrete excess glutamate and destroy surrounding normal peritumoral brain by means of excitotoxic mechanisms. In this study the authors assessed the effect on survival of 2 glutamate modulators (riluzole and memantine) in rodent glioma models. Methods In an in vitro growth inhibition assay, F98 and 9L cells were exposed to riluzole and memantine. Mouse cerebellar organotypic cultures were implanted with F98 glioma cells and treated with radiation, radiation + riluzole, or vehicle and assessed for tumor growth. Safety and tolerability of intracranially implanted riluzole and memantine CPP:SA polymers were tested in F344 rats. The efficacy of these drugs was tested against the 9L model and riluzole was further tested with and without radiation therapy (RT). Results In vitro assays showed effective growth inhibition of both drugs on F98 and 9L cell lines. F98 organotypic cultures showed reduced growth of tumors treated with radiation and riluzole in comparison with untreated cultures or cultures treated with radiation or riluzole alone. Three separate efficacy experiments all showed that localized delivery of riluzole or memantine is efficacious against the 9L gliosarcoma tumor in vivo. Systemic riluzole monotherapy was ineffective; however, riluzole given with RT resulted in improved survival. Conclusions Riluzole and memantine can be safely and effectively delivered intracranially via polymer in rat glioma models. Both drugs demonstrate efficacy against the 9L gliosarcoma and F98 glioma in vitro and in vivo. Although systemic riluzole proved ineffective in increasing survival, riluzole acted synergistically with radiation and increased survival compared with RT or riluzole alone.
Journal of Neurosurgery 01/2014; · 3.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Object Over the past several years, there has been increasing interest in combining angiogenesis inhibitors with radiotherapy and temozolomide chemotherapy in the treatment of glioblastoma. Although the US FDA approved bevacizumab for the treatment of glioblastoma in 2009, the European Medicines Agency rejected its use due to its questionable impact on patient survival. One factor contributing to the failure of angiogenesis inhibitors to increase overall patient survival may be their inability to cross the blood-brain barrier. Here the authors examined in a 9L glioma model whether intracranial polymer-based delivery of the angiogenesis inhibitor minocycline potentiates the effects of both radiotherapy and temozolomide chemotherapy in increasing median survival. The authors also investigated whether the relative timing of minocycline polymer implantation with respect to radiotherapy affects the efficacy of radiotherapy. Methods Minocycline was incorporated into the biodegradable polymer polyanhydride poly(1,3-bis-[p-carboxyphenoxy propane]-co-[sebacic anhydride]) (CPP:SA) at a ratio of 50:50 by weight. Female Fischer 344 rats were implanted with 9L glioma on Day 0. The minocycline polymer was then implanted on either Day 3 or Day 5 posttumor implantation. Cohorts of rats were exposed to 20 Gy focal radiation on Day 5 or were administered oral temozolomide (50 mg/kg daily) on Days 5-9. Results Both minocycline polymer implantations on Days 3 and 5 increased survival from 14 days to 19 days (p < 0.001 vs control). Treatment with a combination of both minocycline polymer and radiotherapy on Day 5 resulted in a 139% increase in median survival compared with treatment with radiotherapy alone (p < 0.005). There was not a statistically significant difference in median survival between the group that received minocycline implanted on the same day as radiotherapy and the group that received minocycline polymer 2 days prior to radiotherapy. Lastly, treatment with a combination of minocycline polymer with oral temozolomide resulted in a 38% extension of median survival compared with treatment of oral temozolomide alone (p < 0.001). Conclusions These results show that minocycline delivered locally potentiates the effects of both radiotherapy and oral temozolomide in increasing median survival in a rodent glioma model. More generally, these results suggest that traditional therapy in combination with local, as opposed to systemic, delivery of angiogenesis inhibitors may be able to increase median survival for patients with glioblastoma.
Journal of Neurosurgery 12/2013; · 3.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: IntroductionSurgery is first-line therapy for glioblastoma, and there is evidence that gross total resection is associated with improved survival. Gross total resection, however, is not always possible, and relationships among extent (percent) of resection (EOR), residual volume (RV), and survival are unknown. The goals were to evaluate whether there is an association between EOR and RV with survival and recurrence and to establish minimum EOR and maximum RV thresholds.Methods
Adult patients who underwent primary glioblastoma surgery from 2007 to 2011 were retrospectively reviewed. Three-dimensional volumetric tumor measurements were made. Multivariate proportional hazards regression analysis was used to evaluate the relationship between EOR and RV with survival and recurrence.ResultsOf 259 patients, 203 (78%) died and 156 (60%) had tumor recurrence. The median survival and progression-free survival were 13.4 and 8.9 months, respectively. The median (interquartile range) pre- and postoperative tumor volumes were 32.2 (14.0-56.3) and 2.1 (0.0-7.9) cm(3), respectively. EOR was independently associated with survival (hazard ratio [HR], 0.995; 95% confidence interval [CI]: 0.990-0.998; P = .008) and recurrence (HR [95% CI], 0.992 [0.983-0.998], P = .005). The minimum EOR threshold for survival (P = .0006) and recurrence (P = .005) was 70%. RV was also associated with survival (HR [95% CI], 1.019 [1.006-1.030], P = .004) and recurrence (HR [95% CI], 1.024 [1.001-1.044], P = .03). The maximum RV threshold for survival (P = .01) and recurrence (P = .01) was 5 cm(3).Conclusion
This study shows for the first time that both EOR and RV are significantly associated with survival and recurrence, where the thresholds are 70% and 5 cm(3), respectively. These findings may help guide surgical and adjuvant therapies aimed at optimizing outcomes for glioblastoma patients.
[Show abstract][Hide abstract] ABSTRACT: IntroductionSurgery is first-line therapy for glioblastoma, and there is evidence that gross total resection is associated with improved survival. Gross total resection, however, is not always possible, and relationships among extent (percent) of resection (EOR), residual volume (RV), and survival are unknown. The goals were to evaluate whether there is an association between EOR and RV with survival and recurrence and to establish minimum EOR and maximum RV thresholds.MethodsAdult patients who underwent primary glioblastoma surgery from 2007 to 2011 were retrospectively reviewed. Three-dimensional volumetric tumor measurements were made. Multivariate proportional hazards regression analysis was used to evaluate the relationship between EOR and RV with survival and recurrence.ResultsOf 259 patients, 203 (78%) died and 156 (60%) had tumor recurrence. The median survival and progression-free survival were 13.4 and 8.9 months, respectively. The median (interquartile range) pre- and postoperative tumor volumes were 32.2 (14.0-56.3) and 2.1 (0.0-7.9) cm3, respectively. EOR was independently associated with survival (hazard ratio [HR], 0.995; 95% confidence interval [CI]: 0.990-0.998; P = .008) and recurrence (HR [95% CI], 0.992 [0.983-0.998], P = .005). The minimum EOR threshold for survival (P = .0006) and recurrence (P = .005) was 70%. RV was also associated with survival (HR [95% CI], 1.019 [1.006-1.030], P = .004) and recurrence (HR [95% CI], 1.024 [1.001-1.044], P = .03). The maximum RV threshold for survival (P = .01) and recurrence (P = .01) was 5 cm3.ConclusionThis study shows for the first time that both EOR and RV are significantly associated with survival and recurrence, where the thresholds are 70% and 5 cm3, respectively. These findings may help guide surgical and adjuvant therapies aimed at optimizing outcomes for glioblastoma patients.
[Show abstract][Hide abstract] ABSTRACT: Anti-angiogenic agents, such as bevacizumab (BEV), can induce normalization of the blood brain barrier, which may influence the penetration and activity of a co-administered cytotoxic drug. However, it is unknown whether this effect is associated with a benefit in overall survival. This study employed intracranial human glioma models to evaluate the effect of BEV alone and in combination with temozolomide (TMZ) and/or radiation therapy (XRT) on overall survival. One hundred eight male athymic rats were intracranially injected with either U251 or U87 human glioma. Ten or eleven days after tumor inoculation, animals bearing U251 and U87, respectively, were treated with: TMZ alone (50 mg/kg for 5 consecutive days, P.O.), BEV alone (15 mg/kg, I.V.), a combination of TMZ and BEV, or a combination of TMZ, BEV, and a single fraction of XRT (20 Gy). Controls received no treatment. The U87 experiment was repeated and the relationship between survival and the extent of anti-angiogenesis via anti-laminin antibodies for the detection of blood vessels was assessed. In both U87 glioma experiments, all of the treatment groups had a statistically significant increase in survival as compared to the control groups. Also, for both U87 experiments the combination groups of TMZ and BEV had significantly better survival when compared to either treatment administered alone, with 75 % of animals demonstrating long-term survival (LTS) (defined as animals alive 120 days after tumor implantation) in one experiment and 25 % LTS in the repeat experiment. In the U251 glioma experiment, all treated groups (except BEV alone) had significantly improved survival as compared to controls with minimal statistical variance among groups. The percent vessel area was lowest in the group of animals treated with BEV alone. The addition of BEV to TMZ and/or XRT had variable effect on prolonging survival in the two human glioma models tested with reduced tumor vascularity in groups treated with BEV. These results indicate that BEV has anti-angiogenic activity and does not seem to hinder the effect of TMZ.
Journal of Neuro-Oncology 11/2013; · 3.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The management of patients with brain metastases is typically dependent on their prognosis. Recursive partitioning analysis (RPA) is the most commonly used method for prognosticating survival, but has limitations for patients in the intermediate class. The aims of this study were to ascertain preoperative risk factors associated with survival, develop a preoperative prognostic grading system, and evaluate the utility of this system in predicting survival for RPA Class 2 patients.
Adult patient who underwent intracranial metastatic tumor surgery at an academic tertiary-care institution from 1997-2011 were retrospectively reviewed. Multivariate proportional hazards regression analysis was used to identify preoperative factors associated with survival. The identified associations were then used to develop a grading system. Survival as a function of time was plotted using Kaplan-Meier method, and survival rates were compared using Log-rank analyses.
421 (59%) of 708 patients were RPA2. The preoperative factors found to be associated with poorer survival were: male gender (p<0.0001), motor deficit (p=0.0007), cognitive deficit (p=0.0004), non-solitary metastases (p=0.002), and tumor size >2cm (p=0.003). Patients possessing 0-1, 2, and 3-5 of these variables were assigned a preoperative grade of A, B, and C, respectively. Patients with a preoperative grade of A, B, and C had a median survival of 17.0, 10.3, and 7.3 months, respectively. These grades all had distinct survival times (p<0.05).
The present study devised a preoperative grading system that may provide prognostic information for RPA2 patients, which may also guide medical and surgical therapies before any intervention is pursued.
[Show abstract][Hide abstract] ABSTRACT: Patients with cerebellar and non-cerebellar metastases are often included in the same study population, even though posterior fossa lesions typically have different presenting symptoms, clinical outcomes, and complications. This is because the outcomes for patients with cerebellar metastases are unclear.
Adult patients who underwent surgery for an intracranial metastasis (single or multiple) between 2007 and 2011 were retrospectively reviewed. Stepwise multivariate proportional hazards regression analysis was used to identify an association between cerebellar location with survival and recurrence.
Of the 708 patients who underwent intracranial metastatic surgery, 140 (19.8%) had surgery for cerebellar metastasis. A cerebellar location was associated with poorer survival [RR (95% CI); 1.231 (1.016?1.523), P = 0.04] and increased spinal recurrence [RR (95% CI); 2.895 (1.491?5.409), P = 0.002], but not local (P = 0.61) or distal recurrence (P = 0.88). The factors independently associated with prolonged survival for patients with cerebellar metastases were: decreasing number of intracranial metastases (P = 0.0002), decreasing tumor size (P = 0.002), and radiation (P = 0.0006). The factors associated with prolonged local progression free survival were: decreasing tumor size (P = 0.0009), non small cell lung cancer (NSCLC) (P = 0.006), non-bladder cancer (P = 0.0005), and post-operative radiation therapy (P = 0.02). The factors independently associated with prolonged distal progression free survival were: age > 40 years (P = 0.02), surgical resection (P = 0.01), and whole brain radiation (WBRT) therapy (P = 0.02).
Patients with cerebellar metastases have more distinct clinical presentations and outcomes than patients with non-cerebellar lesions. The findings of this study may help risk stratify and guide treatment regimens aimed at maximizing outcomes for patients with cerebellar metastases.
Neurological Research 09/2013; · 1.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Patients with a variety of different primary cancers can develop intracranial metastases. Patients who develop intracranial metastases are often grouped into the same study population, and therefore an understanding of outcomes for patients with different primary cancers remain unclear.
Adults who underwent intracranial metastatic tumor surgery from 1997?2011 at a single institution were retrospectively reviewed. Primary pathologies were compared using Fisher's exact and Student's t-test, and Cox regression analysis was used to identify factors associated with survival.
About 708 patients underwent surgery during the reviewed period, where 269(38%) had non-small cell lung cancer (NSCLC), 106(15%) breast cancer (BC), 72(10%) gastrointestinal (GI) cancers, 88(12%) renal cell cancer (RCC), and 88(12%) melanoma. The most notable differences were that NSCLC patients were older, BC younger, BC had more primary tumor control, and NSCLC less extracranial spread. BC had longer survival, RCC had longer local progression free survival (PFS), and NSCLC had longer distal PFS. The factors independently associated with survival for NSCLC (female, recursive partitioning analysis (RPA) class, primary tumor control, solitary metastasis, tumor size, adenocarcinoma, radiation, discharge to home), BC (age, no skull base involvement, radiation), GI cancer (age, RPA class, Karnofsky performance scale (KPS), lack of preoperative motor deficit, non-esophageal tumors, non-hemorrhagic tumors, avoidance of new deficits), melanoma (preoperative seizures, solitary metastasis, smaller tumor size, discharge to home, chemotherapy), and RCC (KPS, chemotherapy) were distinctly different.
These differences between patients with different primary cancers support the fact that patients with intracranial disease are not all the same and should be studied by their primary pathology.
Neurological Research 08/2013; · 1.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Object Gliomas are known to release excessive amounts of glutamate, inducing glutamate excitotoxic cell death in the peritumoral region and allowing the tumor to grow and to expand. Glutamate transporter upregulation has been shown to be neuroprotective by removing extracellular glutamate in a number of preclinical animal models of neurodegenerative diseases, including amyotrophic lateral sclerosis and Parkinson disease as well as psychiatric disorders such as depression. The authors therefore hypothesized that the protective mechanism of glutamate transporter upregulation would be useful for the treatment of gliomas as well. Methods In this study 9L gliosarcoma cells were treated with a glutamate transporter upregulating agent, thiamphenicol, an antibiotic approved in Europe, which has been shown previously to increase glutamate transporter expression and has recently been validated in a human Phase I biomarker trial for glutamate transporter upregulation. Cells were monitored in vitro for glutamate transporter levels and cell proliferation. In vivo, rats were injected intracranially with 9L cells and were treated with increasing doses of thiamphenicol. Animals were monitored for survival. In addition, postmortem brain tissue was analyzed for tumor size, glutamate transporter levels, and neuron count. Results Thiamphenicol showed little effects on proliferation of 9L gliosarcoma cells in vitro and did not change glutamate transporter levels in these cells. However, when delivered locally in an experimental glioma model in rats, thiamphenicol dose dependently (10-5000 μM) significantly increased survival up to 7 days and concomitantly decreased tumor size from 46.2 mm(2) to 10.2 mm(2) when compared with lesions in nontreated controls. Furthermore, immunohistochemical and biochemical analysis of peritumoral tissue confirmed an 84% increase in levels of glutamate transporter protein and a 72% increase in the number of neuronal cells in the tissue adjacent to the tumor. Conclusions These results show that increasing glutamate transporter expression in peritumoral tissue is neuroprotective. It suggests that glutamate transporter upregulation for the treatment of gliomas should be further investigated and potentially be part of a combination therapy with standard chemotherapeutic agents.
Journal of Neurosurgery 08/2013; · 3.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective Skull base metastases (SBMs) are rare lesions in close proximity to critical neural and vasculature structures. This rarity and complexity have led many to only offer nonsurgical therapies. The surgical outcomes for patients with SBM therefore remain unknown. Design Retrospective, comparison analyses. Setting Johns Hopkins Hospital. Participants All patients who underwent intracranial metastatic tumor surgery. Main Outcome Measure Survival and recurrence. Results Of the 708 patients who underwent intracranial metastatic tumor surgery, 29 (4%) had SBM: 3 (10%) involved the anterior skull base, 7 (24%) the sella, 6 (21%) the orbit, 2 (7%) the sphenoid wing, 3 (10%) the clivus, 4 (14%) the petrous bone, and 4 (14%) the paranasal sinuses. Following surgery, 6 (50%) had improvements in vision and 14 (88%) had improvement and/or maintenance of their cranial nerve symptoms. Three (10%), 0(0%), and 1(3%) developed a new motor, language, and vision deficit, respectively. There were no differences in median survival (10.0 versus 9.2 months, p = 0.48) and local progression-free survival (PFS) (p = 0.52), but there was improved distal PFS (p = 0.04) between patients with and without SBM. Conclusions Patients with SBM are relatively rare. These patients can tolerate surgery with minimal morbidity and mortality, and they have similar prognoses to patients without SBM.
Journal of neurological surgery. Part B, Skull base. 08/2013; 74(4):228-35.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Combining anti-angiogenesis agents with cytotoxic agents for the treatment of malignant gliomas may affect the cytotoxic drug distribution by normalizing the blood-brain barrier (BBB). This study examines the intratumoral concentration of temozolomide (TMZ) in the presence and absence of the pan-VEGF receptor tyrosine kinase inhibitor, cediranib. METHODS: Seven nude rats bearing U87 intracerebral gliomas had a microdialysis probe centered within the tumor. Ten-days after tumor implantation, TMZ (50 mg/kg) was given orally. The extracellular fluid (ECF) concentrations of TMZ within the tumor were assessed via microdialysis for 6 h following TMZ administration. Cediranib (6 mg/kg) was then given orally, and 12 h later, TMZ was re-administered with subsequent microdialysis collection. A subset of animals also underwent functional MRI to assess angiogenesis in vivo at post-inoculation days 12 and 21, before and after the cediranib treatment. RESULTS: After dosing of oral TMZ only, ECF-TMZ mean-C max and area under the concentration curve(AUC0-∞) within the tumor were 0.59 μg/mL and 1.82 μg h/mL, respectively. Post-cediranib, ECF-TMZ mean-C max and AUC0-∞ were 0.83 μg/mL and 3.72 ± 0.61 μg h/mL within the tumor, respectively. This represented a 1.4-fold (p = 0.3) and 2.0-fold (p = 0.06) increase in the ECF-TMZ C max and AUC0-∞, respectively, after cediranib administration. In vivo MRI measurements of the various vascular parameters were consistent with a BBB "normalization" profile following cediranib treatment. CONCLUSIONS: In the U87 intracerebral glioma model, within the first day of administration of cediranib, the intratumoral concentrations of TMZ in tumor ECF were slightly, but not statistically significantly, increased when compared to the treatment of TMZ alone with radiographic evidence of a normalized BBB.
Cancer Chemotherapy and Pharmacology 05/2013; · 2.80 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Patients with glioblastoma (GB) are known to have poor prognoses, and among these patients, those with poor neurological function have an even poorer prognosis. Consequently, aggressive surgeries and adjuvant therapies are often withheld because of this dismal outlook. The effects of aggressive therapies in this small subset of patients remain unknown. The goal of this study was to evaluate outcomes and factors associated with survival for poor functioning patients who underwent aggressive resection of their GB. Adult patients who underwent surgical resection of an intracranial primary GB at an academic tertiary-care institution between 1997 and 2007 were retrospectively reviewed. Patients with a Karnofsky Performance Scale (KPS) score of ⩽60 were included. A total of 100 patients with primary GB met the inclusion criteria. The average age (±standard deviation) and KPS score of this cohort were 54±15years and 53±12, respectively. No patient (0%) experienced perioperative mortality, and 0 (0%), 10 (10%), and 3 (3%) of patients incurred a new or increasing language, motor, and visual deficit, respectively. At last follow-up, 88 (88%) patients died with a median survival of 6.6months. The factors associated with improved survival were age <65year (p=0.005), tumor size >2cm (p=0.01), radical tumor resection (p=0.01), and temozolomide (p=0.001). This study identifies a subset of patients with poor functional status who may benefit from aggressive surgical resection.
Journal of Clinical Neuroscience 04/2013; · 1.25 Impact Factor