scispace - formally typeset
Search or ask a question
Author

Barbara Fisher

Bio: Barbara Fisher is an academic researcher from University of Western Ontario. The author has contributed to research in topics: Radiation therapy & Temozolomide. The author has an hindex of 40, co-authored 116 publications receiving 26509 citations. Previous affiliations of Barbara Fisher include London Health Sciences Centre & Mayo Clinic.


Papers
More filters
Journal ArticleDOI
TL;DR: Combined CT + RT led to longer disease control and survival than did CT or RT alone in cases with no 1p19q deletion, and PCV appeared to offer longer disease Control than temozolomide but without a clear survival advantage.
Abstract: Treatment for newly diagnosed anaplastic oligodendroglial tumors is controversial. Radiotherapy (RT) alone and in combination with chemotherapy (CT) are the most well studied strategies. However, CT alone is often advocated, especially in cases with 1p19q codeletion. We retrospectively identified 1013 adults diagnosed from 1981-2007 treated initially with RT alone (n = 200), CT + RT (n = 528), CT alone (n = 201), or other strategies (n = 84). Median overall survival (OS) was 6.3 years and time to progression (TTP) was 3.1 years. 1p19q codeletion correlated with longer OS and TTP than no 1p or 19q deletion. In codeleted cases, median TTP was longer following CT + RT (7.2 y) than following CT (3.9 y, P = .003) or RT (2.5 y, P < .001) alone but without improved OS; median TTP was longer following treatment with PCV alone than temozolomide alone (7.6 vs. 3.3 y, P = .019). In cases with no deletion, median TTP was longer following CT + RT (3.1 y) than CT (0.9 y, P = .0124) or RT (1.1 y, P < .0001) alone; OS also favored CT + RT (median 5.0 y) over CT (2.2 y, P = .02) or RT (1.9 y, P < .0001) alone. In codeleted cases, CT alone did not appear to shorten OS in comparison with CT + RT, and PCV appeared to offer longer disease control than temozolomide but without a clear survival advantage. Combined CT + RT led to longer disease control and survival than did CT or RT alone in cases with no 1p19q deletion. Ongoing trials will address these issues prospectively.

147 citations

Journal ArticleDOI
TL;DR: It is concluded that most long-term survivors of high-grade glioma will have significant cognitive difficulties, usually evident by the first assessment; some patients will develop profound impairment years later, and few are capable of fully independent living.
Abstract: In a pilot study, two groups of patients with malignant glioma underwent sequential neuropsychological evaluations after successful tumor treatment. Group 1 included nine patients treated from 1981 to 1985; all patients received irradiation and eight underwent chemotherapy. The baseline neuropsychological assessment was performed 1 to 63 months after tumor diagnosis, with follow-up evaluations at irregular intervals over the next 3 to 7 years. Six patients in Group 1 exhibited impairment on most measures at baseline; subsequently, two patients developed profound cognitive impairment. Initially, three patients functioned in the average range on most tasks; thereafter, two deteriorated on one measure each. Group 2 was ascertained prospectively and included 16 patients treated from 1985 to 1987, all of whom received irradiation and chemotherapy. The first evaluation was performed 18 months after diagnosis, then every 6 months for 2 years, and then yearly. Compared to a control group, those in Group 2 had significant cognitive impairment at baseline. Cognitive performance did not change over the next 12 months in 10 patients who remained free of tumor, but within 2 years of baseline testing, deterioration on specific tasks was evident in two of seven disease-free survivors. When last tested, five of six disease-free survivors had deteriorated on one or more measures. Unlike Group 1, severe global cognitive impairment was not seen, perhaps because Group 2 was followed for a shorter time. Verbal and nonverbal composite scores derived from intelligence quotient (IQ) tests showed less impairment at baseline than did other measures and were more likely to remain stable subsequently. Verbal memory and sustained attention were the most impaired at baseline, and verbal learning and flexibility in thinking showed the greatest tendency to decline over time. Cognitive functioning in survivors of high-grade glioma is best measured and monitored by tests that probe a broader spectrum of abilities than IQ. Neuropsychological measures used in this analysis lacked sensitivity at the lower end of the impaired range. Future studies should use tests better able to discern cognitive differences at low performance levels. Based on this experience, the authors conclude that most long-term survivors of high-grade glioma will have significant cognitive difficulties, usually evident by the first assessment; some patients will develop profound impairment years later, and few are capable of fully independent living.

144 citations

Journal ArticleDOI
TL;DR: This study was designed to detect a 43% increase in median survival time (MST) from 40.5 to 57.9 months and a 20% improvement in 3-year overall survival (OS) rate from 54% to 65% at a 10% significance level (1-sided) and 96% power.
Abstract: Purpose Radiation Therapy Oncology Group (RTOG) 0424 was a phase 2 study of a high-risk low-grade glioma (LGG) population who were treated with temozolomide (TMZ) and radiation therapy (RT), and outcomes were compared to those of historical controls. This study was designed to detect a 43% increase in median survival time (MST) from 40.5 to 57.9 months and a 20% improvement in 3-year overall survival (OS) rate from 54% to 65% at a 10% significance level (1-sided) and 96% power. Methods and Materials Patients with LGGs with 3 or more risk factors for recurrence (age ≥40 years, astrocytoma histology, bihemispherical tumor, preoperative tumor diameter of ≥6 cm, or a preoperative neurological function status of >1) were treated with RT (54 Gy in 30 fractions) and concurrent and adjuvant TMZ. Results From 2005 to 2009, 129 evaluable patients (75 males and 54 females) were accrued. Median age was 49 years; 91% had a Zubrod score of 0 or 1; and 69%, 25%, and 6% of patients had 3, 4, and 5 risk factors, respectively. Patients had median and minimum follow-up examinations of 4.1 years and 3 years, respectively. The 3-year OS rate was 73.1% (95% confidence interval: 65.3%-80.8%), which was significantly improved compared to that of prespecified historical control values ( P Conclusions The 3-year OS rate of 73.1% for RTOG 0424 high-risk LGG patients is higher than that reported for historical controls ( P

128 citations

Journal ArticleDOI
TL;DR: This is the first study, to the authors' knowledge, to validate the prognostic importance of MGMT promoter methylation in patients with grade II glioma treated with combined radiotherapy and temozolomide and highlights its potential prognostic value beyond IDH1/2 mutation status.
Abstract: Importance The initial report of NRG Oncology/Radiation Therapy Oncology Group (RTOG) 0424 demonstrated a 3-year overall survival benefit with the addition of temozolomide to radiotherapy compared with a historical control. However, an important end point of the trial—evaluation of the association between O6-methylgaunine-DNA-methyltransferase (MGMT) promoter methylation and survival outcomes—was not previously reported. Objective To examine the proportion of patients in NRG Oncology/RTOG 0424 withMGMTpromoter methylation and its association with survival outcomes. Design, Setting, and Participants Specimens collected were analyzed after trial completion to determineMGMTpromoter methylation andIDH1/2status and the association betweenMGMTstatus and survival outcomes. A model derived from logistic regression (MGMT-STP27) was used to calculateMGMTpromoter methylation status. Univariate and multivariable analyses were performed using the Cox proportional hazards regression model to determine the association ofMGMTstatus with survival outcomes. Patient pretreatment characteristics were included as covariates in multivariable analyses. Main Outcomes and Measures Progression-free survival (PFS) and overall survival (OS). Results Of all 129 eligible patients in NRG Oncology/RTOG 0424, 75 (58.1%) hadMGMTstatus available (median age, 48 years; age range, 20-76 years; 42 [56.0%] male): 57 (76.0%) methylated and 18 (24.0%) unmethylated. A total of 13 unmethylated patients (72.2%) had astrocytoma as opposed to oligoastrocytoma or oligodendroglioma, whereas 23 methylated patients (40.4%) had astrocytoma. On univariate analyses, an unmethylatedMGMTpromoter was significantly associated with worse OS (hazard ratio [HR], 3.52; 95% CI, 1.64-7.56;P Conclusions and Relevance In this study,MGMTpromoter methylation was an independent prognostic biomarker of high-risk, low-grade glioma treated with temozolomide and radiotherapy. This is the first study, to our knowledge, to validate the prognostic importance ofMGMTpromoter methylation in patients with grade II glioma treated with combined radiotherapy and temozolomide and highlights its potential prognostic value beyondIDH1/2mutation status. Trial Registration ClinicalTrials.gov Identifier:NCT00114140

118 citations

Journal ArticleDOI
TL;DR: This regimen is safe, with the best 2-year OS and PFS achieved in any Radiation Therapy Oncology Group primary CNS lymphoma trial, and Randomized trials that incorporate this regimen are needed to determine its efficacy compared with other strategies.
Abstract: PurposeThis study investigated the treatment of primary CNS lymphoma with methotrexate, temozolomide (TMZ), and rituximab, followed by hyperfractionated whole-brain radiotherapy (hWBRT) and subsequent TMZ. The primary phase I end point was the maximum tolerated dose of TMZ. The primary phase II end point was the 2-year overall survival (OS) rate. Secondary end points were preirradiation response rates, progression-free survival (PFS), neurologic toxicities, and quality of life.Patients and MethodsThe phase I study increased TMZ doses from 100 to 150 to 200 mg/m2. Patients were treated with rituximab 375 mg/m2 3 days before cycle 1; methotrexate 3.5 g/m2 with leucovorin on weeks 1, 3, 5, 7, and 9; TMZ daily for 5 days on weeks 4 and 8; hWBRT 1.2 Gy twice-daily on weeks 11 to 13 (36 Gy); and TMZ 200 mg/m2 daily for 5 days every 28 days on weeks 14 to 50.ResultsThirteen patients (one ineligible) were enrolled in phase I of the study. The maximum tolerated dose of TMZ was 100 mg/m2. Dose-limiting toxicities w...

102 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: The addition of temozolomide to radiotherapy for newly diagnosed glioblastoma resulted in a clinically meaningful and statistically significant survival benefit with minimal additional toxicity.
Abstract: methods Patients with newly diagnosed, histologically confirmed glioblastoma were randomly assigned to receive radiotherapy alone (fractionated focal irradiation in daily fractions of 2 Gy given 5 days per week for 6 weeks, for a total of 60 Gy) or radiotherapy plus continuous daily temozolomide (75 mg per square meter of body-surface area per day, 7 days per week from the first to the last day of radiotherapy), followed by six cycles of adjuvant temozolomide (150 to 200 mg per square meter for 5 days during each 28-day cycle). The primary end point was overall survival. results A total of 573 patients from 85 centers underwent randomization. The median age was 56 years, and 84 percent of patients had undergone debulking surgery. At a median follow-up of 28 months, the median survival was 14.6 months with radiotherapy plus temozolomide and 12.1 months with radiotherapy alone. The unadjusted hazard ratio for death in the radiotherapy-plus-temozolomide group was 0.63 (95 percent confidence interval, 0.52 to 0.75; P<0.001 by the log-rank test). The two-year survival rate was 26.5 percent with radiotherapy plus temozolomide and 10.4 percent with radiotherapy alone. Concomitant treatment with radiotherapy plus temozolomide resulted in grade 3 or 4 hematologic toxic effects in 7 percent of patients.

16,653 citations

Journal ArticleDOI
TL;DR: Benefits of adjuvant temozolomide with radiotherapy lasted throughout 5 years of follow-up, and a benefit of combined therapy was recorded in all clinical prognostic subgroups, including patients aged 60-70 years.
Abstract: BACKGROUND: In 2004, a randomised phase III trial by the European Organisation for Research and Treatment of Cancer (EORTC) and National Cancer Institute of Canada Clinical Trials Group (NCIC) reported improved median and 2-year survival for patients with glioblastoma treated with concomitant and adjuvant temozolomide and radiotherapy. We report the final results with a median follow-up of more than 5 years. METHODS: Adult patients with newly diagnosed glioblastoma were randomly assigned to receive either standard radiotherapy or identical radiotherapy with concomitant temozolomide followed by up to six cycles of adjuvant temozolomide. The methylation status of the methyl-guanine methyl transferase gene, MGMT, was determined retrospectively from the tumour tissue of 206 patients. The primary endpoint was overall survival. Analyses were by intention to treat. This trial is registered with Clinicaltrials.gov, number NCT00006353. FINDINGS: Between Aug 17, 2000, and March 22, 2002, 573 patients were assigned to treatment. 278 (97%) of 286 patients in the radiotherapy alone group and 254 (89%) of 287 in the combined-treatment group died during 5 years of follow-up. Overall survival was 27.2% (95% CI 22.2-32.5) at 2 years, 16.0% (12.0-20.6) at 3 years, 12.1% (8.5-16.4) at 4 years, and 9.8% (6.4-14.0) at 5 years with temozolomide, versus 10.9% (7.6-14.8), 4.4% (2.4-7.2), 3.0% (1.4-5.7), and 1.9% (0.6-4.4) with radiotherapy alone (hazard ratio 0.6, 95% CI 0.5-0.7; p<0.0001). A benefit of combined therapy was recorded in all clinical prognostic subgroups, including patients aged 60-70 years. Methylation of the MGMT promoter was the strongest predictor for outcome and benefit from temozolomide chemotherapy. INTERPRETATION: Benefits of adjuvant temozolomide with radiotherapy lasted throughout 5 years of follow-up. A few patients in favourable prognostic categories survive longer than 5 years. MGMT methylation status identifies patients most likely to benefit from the addition of temozolomide. FUNDING: EORTC, NCIC, Nelia and Amadeo Barletta Foundation, Schering-Plough.

6,161 citations

Journal ArticleDOI
TL;DR: Patients with glioblastoma containing a methylated MGMT promoter benefited from temozolomide, whereas those who did not have a methylation of theMGMT promoter did notHave such a benefit and were assigned to only radiotherapy.
Abstract: background Epigenetic silencing of the MGMT (O 6 -methylguanine–DNA methyltransferase) DNArepair gene by promoter methylation compromises DNA repair and has been associated with longer survival in patients with glioblastoma who receive alkylating agents. methods We tested the relationship between MGMT silencing in the tumor and the survival of patients who were enrolled in a randomized trial comparing radiotherapy alone with radiotherapy combined with concomitant and adjuvant treatment with temozolomide. The methylation status of the MGMT promoter was determined by methylation-specific polymerase-chain-reaction analysis. results The MGMT promoter was methylated in 45 percent of 206 assessable cases. Irrespective of treatment, MGMT promoter methylation was an independent favorable prognostic factor (P<0.001 by the log-rank test; hazard ratio, 0.45; 95 percent confidence interval, 0.32 to 0.61). Among patients whose tumor contained a methylated MGMT promoter, a survival benefit was observed in patients treated with temozolomide and radiotherapy; their median survival was 21.7 months (95 percent confidence interval, 17.4 to 30.4), as compared with 15.3 months (95 percent confidence interval, 13.0 to 20.9) among those who were assigned to only radiotherapy (P=0.007 by the log-rank test). In the absence of methylation of the MGMT promoter, there was a smaller and statistically insignificant difference in survival between the treatment groups. conclusions Patients with glioblastoma containing a methylated MGMT promoter benefited from temozolomide, whereas those who did not have a methylated MGMT promoter did not have such a benefit.

6,018 citations

Journal ArticleDOI
26 Sep 2008-Science
TL;DR: Recurrent mutations in the active site of isocitrate dehydrogenase 1 (IDH1) occurred in a large fraction of young patients and in most patients with secondary GBMs and were associated with an increase in overall survival.
Abstract: Glioblastoma multiforme (GBM) is the most common and lethal type of brain cancer. To identify the genetic alterations in GBMs, we sequenced 20,661 protein coding genes, determined the presence of amplifications and deletions using high-density oligonucleotide arrays, and performed gene expression analyses using next-generation sequencing technologies in 22 human tumor samples. This comprehensive analysis led to the discovery of a variety of genes that were not known to be altered in GBMs. Most notably, we found recurrent mutations in the active site of isocitrate dehydrogenase 1 (IDH1) in 12% of GBM patients. Mutations in IDH1 occurred in a large fraction of young patients and in most patients with secondary GBMs and were associated with an increase in overall survival. These studies demonstrate the value of unbiased genomic analyses in the characterization of human brain cancer and identify a potentially useful genetic alteration for the classification and targeted therapy of GBMs.

5,250 citations

Journal ArticleDOI
TL;DR: Mutations of NADP(+)-dependent isocitrate dehydrogenases encoded by IDH1 and IDH2 occur in a majority of several types of malignant gliomas.
Abstract: Background A recent genomewide mutational analysis of glioblastomas (World Health Organization [WHO] grade IV glioma) revealed somatic mutations of the isocitrate dehydrogenase 1 gene (IDH1) in a fraction of such tumors, most frequently in tumors that were known to have evolved from lower-grade gliomas (secondary glioblastomas). Methods We determined the sequence of the IDH1 gene and the related IDH2 gene in 445 central nervous system (CNS) tumors and 494 non-CNS tumors. The enzymatic activity of the proteins that were produced from normal and mutant IDH1 and IDH2 genes was determined in cultured glioma cells that were transfected with these genes. Results We identified mutations that affected amino acid 132 of IDH1 in more than 70% of WHO grade II and III astrocytomas and oligodendrogliomas and in glioblastomas that developed from these lower-grade lesions. Tumors without mutations in IDH1 often had mutations affecting the analogous amino acid (R172) of the IDH2 gene. Tumors with IDH1 or IDH2 mutations h...

4,853 citations