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Tracy T Batchelor

Publications and source records attributed to Tracy T Batchelor.

At least 19 recordsLinked to original sources
PubMed2007

AZD2171, a pan-VEGF receptor tyrosine kinase inhibitor, normalizes tumor vasculature and alleviates edema in glioblastoma patients.

Using MRI techniques, we show here that normalization of tumor vessels in recurrent glioblastoma patients by daily administration of AZD2171-an oral tyrosine kinase inhibitor of VEGF receptors-has rapid onset, is prolonged but reversible, and has the significant clinical benefit of alleviating edema. Reversal of normalization began by 28 days, though some features persisted for as long as four months. Basic FGF, SDF1alpha, and viable circulating endothelial cells (CECs) increased when tumors escaped treatment, and circulating progenitor cells (CPCs) increased when tumors progressed after drug interruption. Our study provides insight into different mechanisms of action of this class of drugs in recurrent glioblastoma patients and suggests that the timing of combination therapy may be critical for optimizing activity against this tumor.

Brain Edema↗
PubMed2006

Primary central nervous system lymphoma: presentation, diagnosis and staging.

Primary central nervous system lymphoma (PCNSL) is a rare form of non-Hodgkin lymphoma that affects the brain, spinal cord, leptomeninges, and eyes. The clinical presentation and neuroimaging appearance of PCNSL differ in immunocompetent patients and in those with acquired immunodeficiency syndrome (AIDS). A magnetic resonance (MR) image of the brain in immunocompetent patients with PCNSL typically demonstrates one or more homogeneously enhancing lesions located in the periventricular white matter, characteristically spanning the corpus callosum. In patients with AIDS, multiple ring-enhancing lesions are more common. After neuroimages raising the suspicion of PCNSL are obtained, a definitive diagnosis should be established in both immunocompetent and AIDS patients by performing pathological analysis of cerebrospinal fluid (CSF), vitreous fluid, or a biopsy specimen. Brain biopsy sampling remains the gold standard for PCNSL diagnosis in all patients, although the possibility of establishing routine, minimally invasive diagnostic procedures in which Epstein-Barr virus polymerase chain reaction (PCR) analysis of the CSF and nuclear imaging are used is currently under investigation in the population of patients with AIDS. At the time of diagnosis, the patient should undergo further evaluation, which should include a physical examination, ophthalmic evaluation with a slit-lamp examination, serum lactate dehydrogenase levels, human immunodeficiency virus testing, computed tomography scans of the chest/abdomen/pelvis, bone marrow biopsy sampling, contrast-enhanced brain MR imaging, and lumbar puncture (LP). Testicular ultrasonography studies should be considered in men. In patients who cannot undergo LP or in those with evidence of spinal cord dysfunction, contrast-enhanced MR imaging of the entire spine should be considered.

Biopsy↗
PubMed2006

The effect of enzyme-inducing antiseizure drugs on the pharmacokinetics and tolerability of procarbazine hydrochloride.

PURPOSE: Procarbazine hydrochloride (PCB) is one of the few anticancer drugs with activity against high-grade gliomas. This study was conducted to determine if the maximum tolerated dose and pharmacokinetics of PCB are affected by the concurrent use of enzyme-inducing antiseizure drugs (EIASD). EXPERIMENTAL DESIGN: Adults with recurrent high-grade glioma were divided into cohorts who were (+) and were not (-) taking EIASDs. PCB was given orally for 5 consecutive days each month. Six patients were evaluated at each dose level beginning with 200 mg/m2/d and escalated using the modified continual reassessment method. Toxicity and response were assessed. Pharmacokinetic studies were done with a new electrospray ionization mass spectrometry assay. RESULTS: Forty-nine patients were evaluated. The maximum tolerated dose was 393 mg/m2/d for the +EIASD group and the highest dose evaluated in -EIASD patients was 334 mg/m2/d. Myelosuppression was the primary dose-limiting toxicity. Significant hepatic dysfunction occurred in three patients in the +EIASD cohort. Four partial responses (8%) and no complete responses were observed. PCB exhibited linear pharmacokinetics with no significant differences between the two cohorts. A marked increase in peak PCB levels was noted on day 5 relative to day 1, which was not attributable to drug accumulation. CONCLUSIONS: This study suggests that (a) EIASD use does not significantly affect the pharmacokinetics of PCB; (b) changes in the peak plasma concentration of PCB, consistent with decreased apparent oral clearance due to autoinhibition of hepatic metabolism, occur with daily dosing; and (c) severe hepatic dysfunction may accompany this administration schedule.

Administration, Oral↗
PubMed2006

A hypermutation phenotype and somatic MSH6 mutations in recurrent human malignant gliomas after alkylator chemotherapy.

Malignant gliomas have a very poor prognosis. The current standard of care for these cancers consists of extended adjuvant treatment with the alkylating agent temozolomide after surgical resection and radiotherapy. Although a statistically significant increase in survival has been reported with this regimen, nearly all gliomas recur and become insensitive to further treatment with this class of agents. We sequenced 500 kb of genomic DNA corresponding to the kinase domains of 518 protein kinases in each of nine gliomas. Large numbers of somatic mutations were observed in two gliomas recurrent after alkylating agent treatment. The pattern of mutations in these cases showed strong similarity to that induced by alkylating agents in experimental systems. Further investigation revealed inactivating somatic mutations of the mismatch repair gene MSH6 in each case. We propose that inactivating somatic mutations of MSH6 confer resistance to alkylating agents in gliomas in vivo and concurrently unleash accelerated mutagenesis in resistant clones as a consequence of continued exposure to alkylating agents in the presence of defective mismatch repair. The evidence therefore suggests that when MSH6 is inactivated in gliomas, alkylating agents convert from induction of tumor cell death to promotion of neoplastic progression. These observations highlight the potential of large scale sequencing for revealing and elucidating mutagenic processes operative in individual human cancers.

Aged↗
PubMed2006

International study on low-grade primary central nervous system lymphoma.

OBJECTIVE: The aim of this study was to characterize the clinical presentation, course, and outcome of low-grade primary central nervous system lymphoma. METHODS: Cases were assessed in a retrospective series collected from 18 cancer centers in 5 countries. RESULTS: Forty patients (18 men, 22 women; median age, 60 years [range, 19-78]) were identified. Involvement of a cerebral hemisphere or deeper brain structures was seen in 37 patients, only leptomeningeal involvement in 2 patients, and spinal cord disease in 1 patient. Chemotherapy/radiotherapy was conducted in 15 patients, radiotherapy alone in 12, chemotherapy alone in 10, and tumor resection alone in 2, whereas 1 patient received no treatment. The median progression-free, disease-specific, and overall survival were 61.5 (range, 0-204), 130 (range, 1-204), and 79 (range, 1-204) months, respectively. Only age 60 years or older was associated with shorter progression-free (p = 0.009), disease-specific (p = 0.015), and overall survival (p = 0.001) in multivariate analysis. INTERPRETATION: Low-grade primary central nervous system lymphoma differs from the high-grade subtype in its pathological, clinical, and radiological features. It has a better long-term outcome than primary central nervous system lymphoma in general with age 60 years or older adversely affecting survival.

Age Factors↗
PubMed2006

Supportive care of brain tumor patients.

The supportive care of patients who have brain tumors consists mainly of the treatment of brain edema, seizures, venous thromboembolism, and cognitive dysfunction. Each of these complications may occur in patients who have primary or metastatic brain tumors. The development of any of these complications significantly increases the morbidity and mortality associated with brain tumors. Effective treatment is usually possible, however, and can result in an improved quality of life for these patients.

Brain Edema↗
PubMed2006

Activation of STAT3, MAPK, and AKT in malignant astrocytic gliomas: correlation with EGFR status, tumor grade, and survival.

Diffuse astrocytic gliomas are the most common human glial tumors with glioblastoma being the most malignant form. Epidermal growth factor receptor (EGFR) gene amplification is one of the most common genetic changes in glioblastoma and can lead to the activation of various downstream signaling molecules, including STAT3, MAPK, and AKT. In this study, we investigated the activation status of these 3 signaling molecules as well as wild-type (EGFRwt) and mutant (EGFRvIII) EGFR in 82 malignant astrocytic gliomas (55 glioblastomas and 27 anaplastic astrocytomas) using immunohistochemistry. The presence of EGFRwt, but not EGFRvIII, immunopositivity correlated significantly with prevalent EGFR gene amplification in glioblastomas. STAT3 and AKT activation correlated significantly with EGFR status, although the correlation for p-STAT3 was attributed exclusively to EGFRvIII. The distribution of these 3 activated molecules varied significantly with tumor grade; although activation of STAT3 was essentially identical between anaplastic astrocytomas and glioblastomas, an increase in the activation of MAPK and AKT appeared to correlate with the progression of anaplastic astrocytoma to glioblastoma. Finally, activated STAT3 and AKT were marginally predictive of improved and worse prognosis, respectively. Taken together, these findings begin to elucidate the interrelationship between these signaling pathways in astrocytic gliomas in vivo.

Astrocytoma↗
PubMed2006

Comparison of linear and volumetric criteria in assessing tumor response in adult high-grade gliomas.

The Response Evaluation Criteria in Solid Tumors, or RECIST criteria (one-dimensional [1D] measurement), are widely used to measure response in tumors, but there are few studies evaluating these criteria in brain tumors. We compared linear and volumetric measurements in adult high-grade supratentorial enhancing gliomas to determine the agreement between measurements, in defining responses and in their subsequent relation to survival. We hypothesized that the 1D RECIST criteria maybe suitable for response assessment in adult high-grade gliomas. Tumor size on MRI scans in 104 patients with high-grade enhancing gliomas treated on clinical trial protocols was measured by using 1D (greatest length), 2D (two-dimensional: product of the two longest perpendicular diameters), 3D (three dimensional: product of the longest perpendicular diameters in one plane and the longest orthogonal diameter to that plane), enhancing volume (EV), and total volume (TV). A total of 388 T1 postgadolinium MRI scans (104 baseline and 284 follow-up scans) were evaluated. Volumetric analysis (EV and TV) was performed with commercially available software. Intraobserver and interobserver correlations (rho) were high for all modalities (rho > 0.92 and rho > 0.71, respectively). Correlation was excellent (rho > 0.9) among all modalities except for 3D (rho < 0.6). Patient response rates ranged from 12% to 26%. Median progression-free survival (mPFS) and six-month progression-free survival (6mPFS) were not significantly different among the methods (range, 5.3 months to 5.9 months and 42% to 48%, respectively). Landmark analyses of response at two months using linear methods predicted overall survival with hazard ratios of 0.19 to 0.29 (P < 0.005). These results suggest high concordance among 1D, 2D, TV, and EV, but not 3D, methods in assessing enhancing tumor progression and in estimating mPFS and 6mPFS in adult brain tumor patients. The tumor response at two months assessed by linear methods correlated better with overall survival. Thus, linear methods are comparable to volumetric methods, but simpler to implement for routine clinical use and for designing clinical trials of brain tumors.

Adult↗
PubMed2005

Magnetic resonance imaging characteristics predict epidermal growth factor receptor amplification status in glioblastoma.

PURPOSE: Two clinical-molecular glioblastoma subtypes have been described: "primary" glioblastomas arise de novo in older patients and often overexpress epidermal growth factor receptor (EGFR); "secondary" glioblastomas progress from lower-grade tumors in younger patients and commonly have TP53 mutations. EGFR overexpression correlates in experimental gliomas with increased angiogenesis, edema, and invasion. No radiographic predictors of molecular glioblastoma subtype are known. EXPERIMENTAL DESIGN: We retrospectively reviewed 75 glioblastomas, classified as TP53-mutated (n=11), EGFR-amplified (n=31), or neither (non-TP53/non-EGFR; n=33). Four variables were derived from preoperative magnetic resonance imaging: (a) T2/T1, the ratio of T2-bright volume to enclosed T1-enhancing volume; (b) percentage of tumor volume that was necrosis; and (c and d) T1 and T2 border sharpness coefficients (BSC), the rates of change in grayscale intensity of adjacent 0.02-cm2 voxels traversing the anterior, posterior, and lateral borders on T1-enhanced and T2 images. RESULTS AND CONCLUSIONS: Mean T2/T1 was 4.7 for EGFR-amplified glioblastomas, greater than that of TP53-mutated glioblastomas (2.3) or non-TP53/non-EGFR glioblastomas (2.6; P<0.00005). All four tumors with T2/T1>7.2 were EGFR-amplified; 0 of 15 with T2/T1<4.7 underwent gross total resection. The mean T2 BSC of EGFR-amplified glioblastomas was 33.7, less sharp (P<0.0000005) than TP53-mutated (72.2) and non-TP53/non-EGFR glioblastomas (81.2). All 15 glioblastomas with T2 BSC<30.8 were EGFR-amplified. Percentage necrosis and T1 BSC did not differ between glioblastoma subtypes. The increased T2/T1 ratio and decreased T2 BSC in EGFR-overexpressing tumors are the first radiographic distinctions described between glioblastoma molecular subtypes. These findings may reflect increased angiogenesis, edema, and/or invasion in EGFR-overexpressing tumors.

Brain Neoplasms↗
PubMed2005

Genetic analyses for predictors of radiation response in glioblastoma.

PURPOSE: Radiotherapy (RT) for patients with glioblastoma improves survival and is recommended for nearly all patients with this diagnosis. However, the response to RT is variable in this patient population. Prior studies have suggested that underlying genetic alterations in the tumor may account for some of this treatment-related heterogeneity. It has been previously reported that epidermal growth factor receptor (EGFR) gene amplification and TP53 mutation correlate with the response to RT in patients with glioblastoma. METHODS AND MATERIALS: We sought to identify molecular markers that could predict the response to RT, progression-free survival after RT, and overall survival among 75 glioblastoma patients treated with RT at a single institution. Genetic analyses assessed EGFR amplification, TP53 mutations, CDKN2A/p16 deletion, and losses of chromosomes 1p, 10q, and 19q. RESULTS: Unlike previous reports, no association of EGFR amplification with response to RT, progression-free survival, or overall survival was found. Moreover, no association was found between these endpoints and the other genetic alterations assayed (TP53 mutation, CDKN2A/p16 deletion, loss of heterozygosity 1p, loss of heterozygosity 10q, and loss of heterozygosity 19q). However, in accordance with recent observations that the prognostic effects of genetic alterations in glioblastoma may depend on patient age, we observed age-dependent prognostic effects of TP53 and CDKN2A/p16 alterations in our patient population. For patients > or = 57 years old, those harboring TP53 mutations had a decreased overall survival compared with patients without TP53 mutations. Similarly, deletion of CDKN2A/p16 in patients > or = 57 years was associated with decreased progression-free survival after RT and a trend toward a shorter time to progression after RT compared with similar patients without the deletion. CONCLUSION: These data contrast with previous studies regarding the significant prognostic effect of EGFR with respect to RT response. Although our observations regarding the age-dependent prognostic effects of TP53 and CDKN2A/p16 are consistent with a prior report regarding these alterations, the present results should be considered preliminary, given the small sample size.

Adolescent↗
PubMed2005

Report of an international workshop to standardize baseline evaluation and response criteria for primary CNS lymphoma.

Standardized guidelines for the baseline evaluation and response assessment of primary CNS lymphoma (PCNSL) are critical to ensure comparability among clinical trials for newly diagnosed patients. The relative rarity of this tumor precludes rapid completion of large-scale phase III trials and, therefore, our reliance on the results of well-designed phase II trials is critical. To formulate this recommendation, an international group of experts representing hematologic oncology, medical oncology, neuro-oncology, neurology, radiation oncology, neurosurgery, and ophthalmology met to review current standards of reporting and to formulate a consensus opinion regarding minimum baseline evaluation and common standards for assessing response to therapy. The response guidelines were based on the results of neuroimaging, corticosteroid use, ophthalmologic examination, and CSF cytology. A critical issue that requires additional study is the optimal method to assess the neurocognitive impact of therapy and address the quality of life of PCNSL survivors. We hope that these guidelines will improve communication among investigators and comparability among clinical trials in a way that will allow us to develop better therapies for patients.

Central Nervous System Neoplasms↗
PubMed2005

YKL-40 is a differential diagnostic marker for histologic subtypes of high-grade gliomas.

PURPOSE AND EXPERIMENTAL DESIGN: In modern neuro-oncology, no variable affects therapeutic decisions and prognostic estimation more than tumor classification. We showed recently that class prediction models, based on gene expression profiles, classify diagnostically challenging malignant gliomas in a manner that better correlates with clinical outcome than standard pathology. In the present study, we used immunohistochemistry to investigate YKL-40 protein expression in independent sets of glioblastomas and anaplastic oligodendrogliomas to determine whether this single marker can aid classification of these high-grade gliomas. RESULTS AND CONCLUSIONS: Glioblastomas show strikingly more YKL-40 expression than anaplastic oligodendrogliomas. Only 2 of 37 glioblastomas showed completely negative YKL-40 staining in both tumor cells and extracellular matrix, whereas 18 of 29 anaplastic oligodendrogliomas were completely negative in non-microgemistocytic tumor cells and extracellular matrix. Tumor cell staining intensity was also markedly different: 84% of glioblastomas showed strong staining intensities of 2+ or 3+ whereas 76% of anaplastic oligodendrogliomas either did not stain or stained at only 1+. YKL-40 staining provided a better class distinction of glioblastoma versus anaplastic oligodendroglioma than glial fibrillary acidic protein, the current standard immunohistochemical marker used to distinguish diagnostically challenging gliomas. Moreover, a combination of YKL-40 and glial fibrillary acidic protein immunohistochemistry afforded even greater diagnostic accuracy in anaplastic oligodendrogliomas.

Adipokines↗
PubMed2005

Results of whole-brain radiation as salvage of methotrexate failure for immunocompetent patients with primary CNS lymphoma.

PURPOSE: This study evaluates the efficacy and toxicity of whole-brain radiation therapy (WBRT) as salvage therapy for immunocompetent patients who failed initial high-dose methotrexate for primary CNS lymphoma (PCNSL). PATIENTS AND METHODS: The study cohort included 27 consecutive patients who failed initial high-dose methotrexate and then received salvage WBRT (median dose, 36 Gy). Actuarial survival was measured from the initiation of radiotherapy. RESULTS: Ten patients (37%) achieved a complete radiographic response (CR), and 10 patients (37%) a partial response to WBRT, for a 74% overall radiographic response rate. At the time of maximal response, Karnofsky performance status improved in 12 (44%) of 27 patients and at least stabilized in 67%. Median estimated survival from initiation of WBRT was 10.9 months (range, 0.3 to 63.7 months). The univariate predictor of longer survival was age less than 60 years at the time of WBRT (P = .028). Among patients who survived 4 months, achievement of a CR to WBRT by 4 months (P = .002) predicted longer survival. Late treatment-associated neurotoxicity was diagnosed in four patients (15%) and was significantly associated with total radiation doses greater than 36 Gy (P = .04). No patient treated with daily fractions less than 1.8 Gy developed late neurotoxicity. CONCLUSION: For patients with PCNSL who experience treatment failure with methotrexate, WBRT provides high response rates (74%) and a median survival of 10.9 months. Age less than 60 years and response to WBRT predict post-WBRT survival. Modest rates of late neurotoxicity (15%) were seen and were associated with a total dose greater than 36 Gy.

Antimetabolites, Antineoplastic↗
PubMed2005

Statistical considerations for immunohistochemistry panel development after gene expression profiling of human cancers.

In recent years there have been a number of microarray expression studies in which different types of tumors were classified by identifying a panel of differentially expressed genes. Immunohistochemistry is a practical and robust method for extending gene expression data to common pathological specimens with the advantage of being applicable to paraffin-embedded tissues. However, the number of assays required for successful immunohistochemical classification remains unclear. We propose a simulation-based method for assessing sample size for an immunohistochemistry investigation after a promising gene expression study of human tumors. The goals of such an immunohistochemistry study would be to develop and validate a marker panel that yields improved prognostic classification of cancer patients. We demonstrate how the preliminary gene expression data, coupled with certain realistic assumptions, can be used to estimate the number of immunohistochemical assays required for development. These assumptions are more tenable than alternative assumptions that would be required for crude analytic sample size calculations and that may yield underpowered and inefficient studies. We applied our methods to the design of an immunohistochemistry study for glioma classification and estimated the number of assays required to ensure satisfactory technical and prognostic validation. Simulation approaches for computing power and sample size that are based on existing gene expression data provide a powerful tool for efficient design of follow-up genomic studies.

Computer Simulation↗
PubMed2005

Peripheral and cranial nerve sheath tumors.

PURPOSE OF REVIEW: The intention of the authors is to provide the reader with an overview of the recent advances in the diagnosis and treatment of nerve sheath tumors. Vestibular schwannomas, neurogenetic syndromes such as schwannomatosis and multiple isolated neurofibromas, and malignant peripheral nerve sheath tumors are covered in this review. RECENT FINDINGS: Over the last year, literature focusing on different management strategies for patients with vestibular schwannomas dominated the field. Surgical options for this group of patients are changing. Stereotactic radiation is also employed more frequently with promising results. New insights into the biology of peripheral nerve tumor development and growth, including expression of vascular endothelial growth factor by vestibular schwannomas and the role of Notch signaling in malignant transformation of benign neurofibromas have been described. Diagnostic criteria for schwannomatosis, a recently described condition, are being developed. Several cases of multiple isolated neurofibromas and spinal neurofibromas were reported. SUMMARY: Peripheral nerve tumors are classified according to the specific features of cellular differentiation. The most common types include schwannoma and neurofibroma. These tumors can occur sporadically or as manifestations of genetic syndromes such as neurofibromatosis types 1 and 2 or schwannomatosis. The majority of peripheral nerve tumors are benign but malignant transformation does occur. Metastatic tumors can also affect peripheral nerves. The diagnostic modality of choice is magnetic resonance imaging. Positron emission tomography is a useful technique in the presurgical differentiation between benign and malignant peripheral nerve sheath tumors. Treatment is directed towards symptomatic control. Surgery, radiation and, in rare instances, chemotherapy are the major treatment modalities employed.

Cranial Nerve Neoplasms↗
PubMed2005

Neoadjuvant temozolomide followed by complete resection of a 1p- and 19q-deleted anaplastic oligoastrocytoma: case study.

A 38-year-old woman presented with an infiltrative tumor of the right frontal lobe and genu of the corpus callosum that was deemed only partially resectable. A stereotactic biopsy was performed, which revealed a right frontal oligoastrocytoma that had some anaplastic features as well as allelic loss of chromosome arms 1p and 19q. The patient was treated with temozolomide for 24 months. The partial response of the tumor to chemotherapy rendered the lesion amenable to gross total resection, which was performed subsequently. The patient remains alive and well without evidence of recurrence 7 months after resection and 48 months after initial diagnosis. Thus, preoperative chemotherapy decreased tumor mass to a degree that subsequently enabled a gross total resection. This treatment strategy, although common in the treatment of other solid tumors, is rarely utilized in adult neuro-oncology and raises another potential role for chromosome testing in oligodendroglial tumor management.

Adult↗
PubMed2004

Treatment of relapsed central nervous system lymphoma with high-dose methotrexate.

PURPOSE: Over the past decade, high-dose methotrexate has emerged as the single most effective agent in the initial treatment of primary nervous system lymphoma. However, the majority of patients who respond initially to treatment relapse. The optimal management of these patients has not been determined. We performed a multicenter, retrospective study of high-dose methotrexate in patients with relapsed central nervous system lymphoma. EXPERIMENTAL DESIGN: Patients with relapsed disease were eligible if they achieved a complete response to initial treatment with methotrexate-based chemotherapy or received methotrexate after gross total resection or interstitial radiation. All of the patients were retreated with a regimen containing high-dose methotrexate (>/=3 g/m(2)). RESULTS: Twenty-two patients with a median age of 58 years were included in the study. Overall response rates were 91% to first salvage (20 of 22 patients) and 100% to second salvage (4 of 4 patients). Median survival was 61.9 months after first relapse (95% confidence interval, 42.1- infinity ) and 91.9 months overall (95% confidence interval, 47.2- infinity ). Toxicity was primarily hematologic with 10 episodes of grade 3 or 4 toxicity during 566 cycles of chemotherapy. CONCLUSIONS: These results indicate that high-dose methotrexate remains effective for relapsed central nervous system lymphoma in patients who initially respond to methotrexate and raise the possibility of deferring more toxic salvage regimens in this select group of patients.

Adult↗