Prospective randomized trial of low- versus high-dose radiation therapy in adults with supratentorial low-grade glioma: initial report of a North Central Cancer Treatment Group/Radiation Therapy Oncology Group/Eastern Cooperative Oncology Group study

Management of low-grade glioma

The optimal management of patients with low-grade glioma (LGG) is controversial. The controversy largely stems from the lack of well-designed clinical trials with adequate follow-up to account for the relatively long progression-free survival and overall survival of patients with LGG. Nonetheless, the literature increasingly suggests that expectant management is no longer optimal. Rather, there is mounting evidence supporting active management including consideration of surgical resection, radiotherapy, chemotherapy, molecular and histopathologic characterization, and use of modern imaging techniques for monitoring and prognostication. In particular, there is growing evidence favoring extensive surgical resection and increasing interest in the role of chemotherapy (especially temozolomide) in the management of these tumors. In this review, we critically analyze emerging trends in the literature with respect to management of LGG, with particular emphasis on reports published during the past year.

Functional mapping-guided resection of low-grade gliomas in eloquent areas of the brain: improvement of long-term survival. Clinical article

OBJECT

Low-grade gliomas (LGGs) frequently infiltrate highly functional or "eloquent" brain areas. Given the lack of long-term survival data, the prognostic significance of eloquent brain tumor location and the role of functional mapping during resective surgery in presumed eloquent brain regions are unknown.

METHODS

We performed a retrospective analysis of 281 cases involving adults who underwent resection of a supratentorial LGG at a brain tumor referral center. Preoperative MR images were evaluated blindly for involvement of eloquent brain areas, including the sensorimotor and language cortices, and specific subcortical structures. For high-risk tumors located in presumed eloquent brain areas, long-term survival estimates were evaluated for patients who underwent intraoperative functional mapping with electrocortical stimulation and for those who did not.

RESULTS

One hundred and seventy-four patients (62%) had high-risk LGGs that were located in presumed eloquent areas. Adjusting for other known prognostic factors, patients with tumors in areas presumed to be eloquent had worse overall and progression-free survival (OS, hazard ratio [HR] 6.1, 95% CI 2.6-14.1; PFS, HR 1.9, 95% CI 1.2-2.9; Cox proportional hazards). Confirmation of tumor overlapping functional areas during intraoperative mapping was strongly associated with shorter survival (OS, HR 9.6, 95% CI 3.6-25.9). In contrast, when mapping revealed that tumor spared true eloquent areas, patients had significantly longer survival, nearly comparable to patients with tumors that clearly involved only noneloquent areas, as demonstrated by preoperative imaging (OS, HR 2.9, 95% CI 1.0-8.5).

CONCLUSIONS

Presumed eloquent location of LGGs is an important but modifiable risk factor predicting disease progression and death. Delineation of true functional and nonfunctional areas by intraoperative mapping in high-risk patients to maximize tumor resection can dramatically improve long-term survival.

Radiation oncology in brain tumors: current approaches and clinical trials in progress

Radiation therapy remains a critical therapeutic modality in the treatment of adult brain tumors. However, its use continues to evolve depending on the histologic findings of the brain tumor. In high-grade gliomas, current trials focus on the addition of systemic agents and optimization of target delineation to improve the therapeutic ratio of radiotherapy. In low-grade gliomas, the life expectancy is much greater, and the possibility of late effects of radiotherapy have shaped contemporary trials to attempt to identify groups that benefit from radiotherapy versus the ones that may defer radiotherapy until tumor progression. With primary central nervous system lymphoma, the advent of high-dose methotrexate-based chemotherapy and the risk of severe early neurocognitive toxicity have brought the role of radiotherapy into question. With meningioma, the use of normal tissue-sparing techniques such as radiosurgery has allowed for the successful treatment of patients who are eminently curable and with a life expectancy that is generally no different than that of the general population. Particular attention in this review is paid to current approaches, contemporary trials, and modern therapeutic dilemmas.

Intraoperative stimulation techniques for functional pathway preservation and glioma resection

Although a primary tenet of neurosurgical oncology is that survival can improve with greater tumor resection, this principle must be tempered by the potential for functional loss following a radical removal. Preoperative planning with functional and physiological imaging paradigms, combined with intraoperative strategies such as cortical and subcortical stimulation mapping, can effectively reduce the risks associated with operating in eloquent territory. In addition to identifying critical motor pathways, these techniques can be adapted to identify language function reliably. The authors review the technical nuances of intraoperative mapping for low- and high-grade gliomas, demonstrating their efficacy in optimizing resection even in patients with negative mapping data. Collectively, these surgical strategies represent the cornerstone for operating on gliomas in and around functional pathways.

Radiation dose-volume effects in the brain

We have reviewed the published data regarding radiotherapy (RT)-induced brain injury. Radiation necrosis appears a median of 1-2 years after RT; however, cognitive decline develops over many years. The incidence and severity is dose and volume dependent and can also be increased by chemotherapy, age, diabetes, and spatial factors. For fractionated RT with a fraction size of <2.5 Gy, an incidence of radiation necrosis of 5% and 10% is predicted to occur at a biologically effective dose of 120 Gy (range, 100-140) and 150 Gy (range, 140-170), respectively. For twice-daily fractionation, a steep increase in toxicity appears to occur when the biologically effective dose is >80 Gy. For large fraction sizes (>or=2.5 Gy), the incidence and severity of toxicity is unpredictable. For single fraction radiosurgery, a clear correlation has been demonstrated between the target size and the risk of adverse events. Substantial variation among different centers' reported outcomes have prevented us from making toxicity-risk predictions. Cognitive dysfunction in children is largely seen for whole brain doses of >or=18 Gy. No substantial evidence has shown that RT induces irreversible cognitive decline in adults within 4 years of RT.

[Advances in adults' gliomas biology, imaging and treatment]

A better understanding of gliomas biology is now leading to a combined histo-molecular classification of these tumors. In anaplastic gliomas ongoing studies depend on 1p/19q codeletion status and in glioblastomas on MGMT methylation status. Advanced brain tumor imaging elicits a better identification of gliomas evolutive potential of. In low-grade gliomas, the importance of maximal resection and the role of chemotherapy are being increasingly recognized. In anaplastic gliomas, phase III studies have clarified the respective roles of chemotherapy and radiotherapy. In glioblastomas concomitant chemoradiotherapy is the standard. Most targeted therapies, namely anti-EGFR therapies have failed to demonstrate efficacy but anti-angiogenics are promising. The aim of this review is to discuss the main advances in adults' gliomas biology, imaging and treatment.

Recurrence and malignant degeneration after resection of adult hemispheric low-grade gliomas

Object

Unlike their malignant counterparts, low-grade gliomas are associated with prolonged survival. However, these tumors have a propensity to progress after resection and ultimately undergo malignant degeneration. The factors associated with recurrence and malignant degeneration remain relatively unknown. The authors set out to determine factors that were independently associated with recurrence and malignant degeneration in patients who underwent resection of a hemispheric low-grade glioma.

Methods

Adult patients who underwent craniotomy and resection of a hemispheric low-grade glioma (WHO Grade II) at the Johns Hopkins Medical Institution's academic tertiary-care institution between 1996 and 2006 were retrospectively reviewed. Multivariate proportional hazards regression analyses were used to identify associations with tumor recurrence and malignant degeneration.

Results

Of the 191 consecutive patients with low-grade gliomas in this series (89 fibrillary astrocytomas, 89 oligodendrogliomas, and 13 mixed gliomas), 83 (43%) and 44 (23%) experienced tumor recurrence and malignant degeneration at last follow-up, respectively. The 5-year progression-free and malignancy-free survival rates were 44 and 74%, respectively. Independent predictors of recurrence were duration of longest lasting symptom (relative risk [RR] 0.978, 95% CI 0.954–0.996, p = 0.01), tumor size (RR 1.328, 95% CI 1.109–1.602, p = 0.002), and preoperative contrast enhancement (RR 2.558, 95% CI 1.241–5.021, p = 0.01). Independent factors associated with malignant degeneration were fibrillary astrocytoma pathology (RR 1.800, 95% CI 1.008–4.928, p = 0.04), tumor size (RR 1.086, 95% CI 1.044–1.358, p = 0.04), and gross-total resection (RR 0.526, 95% CI 0.221–1.007, p = 0.05).

Conclusions

The identification and consideration of factors associated with recurrence and malignant progression may help guide treatment strategies aimed at delaying recurrence and preventing malignant degeneration for patients with hemispheric low-grade gliomas.

Is there a place for radiotherapy in low-grade gliomas?

The optimal management of supratentorial low-grade glioma remains controversial, and only limited definitive data is available to guide recommendations. Treatment decisions have to take into account both the management of symptoms and of tumour control, and must balance the benefits against the potential for treatment-related complications. Overall outcome is more dependent on patient and tumour-related characteristics such as age, tumour grade, histology and neurological function than treatment. From the pooled analysis of 2 randomized EORTC trials a prognostic score has been derived, median survival is varying from 3.2 to 7.8 years. Radiation therapy is usually the primary treatment modality; however its benefit on initial tumour control may be outweighed by potential late toxicity. To date only 4 large randomized trials in patients with low-grade glioma have been reported. It allows concluding that early radiotherapy does not improve overall survival and supports an initially expectative approach. Similarly, higher radiation doses above 45-50 Gy (fractions of 1.8-2.0 Gy) do not confer a better outcome but may be associated with increased toxicity. The adjuvant use of PCV-chemotherapy in high-risk patients also failed to improve progression-free and overall survival. An ongoing large randomized EORTC/NCIC trial is investigating the primary treatment with temozolomide chemotherapy versus standard radiotherapy in patients "at need for treatment". Tumour material will be collected in all patients, which ultimately may allow identifying on a molecular basis patients for whom one or another treatment strategy may fit best. Irrespective of new chemotherapeutic agents, radiotherapy is also evolving. Highly conformal techniques based on modern imaging as co-registered MRI scans, limiting the amount of normal tissue irradiated without compromising tumour control, will be the future approach in order to reduce neurotoxicity.

Prognostic factors in pediatric high-grade astrocytoma: the importance of accurate pathologic diagnosis

To characterize a population of pediatric high-grade astrocytoma (HGA) patients by confirming the proportion with a correct diagnosis, and determine prognostic factors for survival in a subset diagnosed with uniform pathologic criteria. Sixty-three children diagnosed with HGA were treated at the Johns Hopkins Hospital between 1977 and 2004. A single neuropathologist (P.C.B.) reviewed all available histologic samples (n = 48). Log-rank analysis was used to compare survival by patient, tumor, and treatment factors. Median follow-up was 16 months for all patients and 155 months (minimum 54 months) for surviving patients. Median survival for all patients (n = 63) was 14 months with 10 long-term survivors (survival >48 months). At initial diagnosis, 27 patients were grade III (43%) and 36 grade IV (57%). Forty-eight patients had pathology slides available for review, including seven of ten long-term surviving patients. Four patients had non-HGA pathology, all of whom were long term survivors. The remaining 44 patients with confirmed HGG had a median survival of 14 months and prognostic analysis was confined to these patients. On multivariate analysis, five factors were associated with inferior survival: performance status (Lansky) <80% (13 vs. 15 months), bilaterality (13 vs. 19 months), parietal lobe location (13 vs. 16 months), resection less than gross total (13 vs. 22 months), and radiotherapy dose <50 Gy (9 vs. 16 months). Among patients with more than one of the five adverse factors (n = 27), median survival and proportion of long-term survivors were 12.9 months and 0%, compared with 41.4 months and 18% for patients with 0-1 adverse factors (n = 17). In an historical cohort of children with HGA, the potential for long term survival was confined to the subset with less than two of the following adverse prognostic factors: low performance status, bilaterality, parietal lobe site, less than gross total resection, and radiotherapy dose <50 Gy. Pathologic misdiagnosis should be suspected in patients who are long term survivors of a pediatric high grade astrocytoma.

Chromosome 9p and 10q losses predict unfavorable outcome in low-grade gliomas

The loss of chromosomes 1p-19q is the only prognostic molecular alteration identified in low-grade gliomas (LGGs) to date. Search for loss of heterozygosity (LOH) on chromosomes 1p, 9p, 10q, and 19q was performed in a series of 231 LGGs. Loss of chromosomes 1p-19q was strongly correlated with prolonged progression-free survival (PFS) and overall survival (OS) in univariate and multivariate analyses. LOH on 9p and 10q were associated with shortened PFS (P = .01 and .03, respectively) on univariate analysis. On multivariate analysis, LOH on 9p remained significant for PFS (P = .05), whereas LOH on 10q had a significant effect on OS (P = .02). Search for LOH 9p and 10q appears to be a useful complement to analysis of chromosomes 1p-19q in LGGs.

Multiinstitutional validation of the University of California at San Francisco Low-Grade Glioma Prognostic Scoring System. Clinical article

OBJECT

Medical and surgical management of low-grade gliomas (LGGs) is complicated by a highly variable clinical course. The authors recently developed a preoperative scoring system to prognosticate outcomes of progression and survival in a cohort of patients treated at a single institution (University of California, San Francisco [UCSF]). The objective of this study was to validate the scoring system in a large patient group drawn from multiple external institutions.

METHODS

Clinical data from 3 outside institutions (University of Utah, Toronto Western Hospital, and University of California, Los Angeles) were collected for 256 patients (external validation set). Patients were assigned a prognostic score based upon the sum of points assigned to the presence of each of the 4 following factors: 1) location of tumor in presumed eloquent cortex, 2) Karnofsky Performance Scale (KPS) Score <or= 80, 3) age > 50 years, and 4) maximum diameter > 4 cm. A chi-square analysis was used to analyze categorical differences between the institutions; Cox proportional hazard modeling was used to confirm that the individual factors were associated with shorter overall survival (OS) and progression-free survival (PFS); and Kaplan-Meier curves estimated OS and PFS for the score groups. Differences between score groups were analyzed by the log-rank test.

RESULTS

The median OS duration was 120 months, and there was no significant difference in survival between the institutions. Cox proportional hazard modeling confirmed that the 4 components of the UCSF Low-Grade Glioma Scoring System were associated with lower OS in the external validation set; presumed eloquent location (hazard ratio [HR] 2.04, 95% CI 1.28-2.56), KPS score <or= 80 (HR 5.88, 95% CI 2.44-13.7), age > 50 years (HR 1.82, 95% CI 1.02-3.23), and maximum tumor diameter > 4 cm (HR 2.63, 95% CI 1.58-4.35). The stratification of patients based on scores generated groups (0-4) with statistically different OS and PFS estimates (p < 0.0001, log-rank test). Lastly, the UCSF patient group (construction set) was combined with the external validation set (total of 537 patients) and analyzed for OS and PFS. For all patients, the 5-year survival probability was 0.79; the 5-year cumulative OS probabilities stratified by score group were: score of 0, 0.98; score of 1, 0.90; score of 2, 0.81; score of 3, 0.53; and score of 4, 0.46.

CONCLUSIONS

The UCSF scoring system accurately predicted OS and PFS in an external large, multiinstitutional population of patients with LGGs. The strengths of this system include ease of use and ability to be applied preoperatively, with the eventual goal of aiding in the design of individualized treatment plans for patients with LGG at diagnosis.

Low-grade oligodendroglioma: an indolent but incurable disease? Clinical article

OBJECT

The authors reviewed their institutional experience with pure low-grade oligodendroglioma (LGO), correlating outcomes with several variables of possible prognostic values.

METHODS

Sixty-nine patients with WHO-classified LGOs were treated between 1992 and 2006 at the McGill University Health Center. Clinical, pathological, and radiological records were carefully reviewed. Demographic characteristics; the nature and duration of presenting symptoms; baseline neurological function; extent of resection; Karnofsky Performance Scale score; preoperative radiological findings including tumor size, location, and absence/presence of enhancement; and pathological data including chromosome arms 1p/19q codeletion and O-methylguanine-DNA methyltransferase promoter gene methylation status were all compiled. The timing and dose of radio- and/or chemotherapy, date of tumor progression, pathological finding at disease progression, treatment at time of disease progression, and status at the last follow-up were also recorded.

RESULTS

The median follow-up period was 6.1 years (range 1.3-16.3 years). The majority (78%) of patients presented with seizures; contrast enhancement was initially seen in 16 patients (25%). All patients had undergone an initial surgical procedure: gross-total resection in 27%, partial resection in 59%, and biopsy only in the remaining 13%. Fifteen patients received adjuvant radiotherapy. Data on O-methylguanine-DNA methyltransferase promoter gene methylation status was available in 47 patients (68%) and in all but 1 patient for 1p/19q status. Survival at 5, 10, and 15 years was 83, 63, and 29%, respectively. Multivariate analysis showed that seizures at presentation and the absence of contrast enhancement were the only independent favorable prognostic factors for survival. The 5-, 10-, and 15-year progression-free survival rates were 46, 7.7, and 0%, respectively.

CONCLUSIONS

This retrospective review confirms the indolent but progressively fatal nature of LGOs. Contrast enhancement was the most evident single prognostic factor. New treatment strategies are clearly needed in the management of this disease.

The role of radiotherapy in the treatment of newly diagnosed supratentorial low-grade oligodendrogliomas: comparative analysis with immediate radiotherapy versus surgery alone

PURPOSE

The purpose of this study was to evaluate the role of immediate postoperative radiotherapy (RT) in adult patients with a low-grade oligodendroglioma (LODG).

MATERIALS AND METHODS

A total of 74 patients, older than 15 years, were treated in our institution between April 1990 and March 2006 for newly diagnosed LODGs. After surgery, 43 patients were treated with immediate RT with a total dose of 54~55.8 Gy with 1.8 Gy fractions (RT group) and 31 patients were followed with no adjuvant RT (OP group). All patients were closely observed until tumor progression or death with frequent work-ups including neurological examinations and MRI. Primary endpoints were overall survival and progression-free survival. The median follow-up duration of survivors was 6.2 years in the RT group and 5.8 years in the OP group.

RESULTS

Median progression-free survival was 13.2 years in the RT group and 4.6 years in the OP group; multivariate analysis confirmed improved outcome with the use of immediate RT (hazard ratio, 0.22; 95% confidence interval-CI, 0.09~0.55; p<0.001). Median overall survival was 14.9 years in the RT group and 9.8 years in the OP group; the use of adjuvant RT was also associated with a trend toward better overall survival after immediate RT based on multivariate analysis (hazard ratio, 0.3; 95% CI, 0.08~1.17; p=0.082). No severe RT related complications were observed.

CONCLUSION

Immediate RT following surgery appears to be an effective treatment modality for supratentorial LODGs. However, the potential benefit of adjuvant RT for overall survival needs to be tested prospectively in the future.

Low-grade gliomas in older patients: long-term follow-up from Mayo Clinic

BACKGROUND

Low-grade gliomas (LGGs) are uncommon in older patients, and long-term clinical behavior and prognostic factors are not well defined in this group.

METHODS

The authors retrospectively searched their tumor registry for the records of adult patients (> or =18 years) diagnosed as having nonpilocytic LGG between 1960 and 1992 at Mayo Clinic. The Kaplan-Meier method was used to estimate progression-free survival and overall survival (OS) in patients aged 55 years and older.

RESULTS

Of 314 patients initially identified, 32 were aged at least 55 years, with a median age at diagnosis of 61 years (range, 55-74 years). Median follow-up was 17.3 years for survivors. Operative pathologic diagnoses comprised astrocytoma (n = 22, 69%), mixed oligoastrocytoma (n = 7, 22%), and oligodendroglioma (n = 3, 9%). Gross total resection was achieved in 1 patient, radical subtotal resection in 1, and subtotal resection in 14; 16 patients had biopsy only. Postoperative radiotherapy or chemotherapy was given to 23 (72%) patients and 1 (3%) patient, respectively. Median OS was 2.7 years for all patients: 3 years with resection and 2.2 years with biopsy only (P = .58). The 5- and 10-year OS rates were 31% and 18%, respectively. Factors adversely affecting OS on univariate analysis were enhancement on computed tomography (P < .001) and supratentorial location (P = .03).

CONCLUSIONS

This retrospective series of older patients suggests that intracranial LGG in this age group behaves aggressively. Pathologic sampling error failing to recognize higher-grade tumors does not seem to account for these poor outcomes. Aggressive management with maximally safe resection followed by adjuvant therapy should be strongly considered.

Applications of neural and mesenchymal stem cells in the treatment of gliomas

In addition to stem cells providing a better understanding about the biology and origins of gliomas, new therapeutic approaches have been developed based on the use of stem cells as delivery vehicles. The unique ability of stem cells to track down tumor cells makes them a very appealing therapeutic modality. This review introduces neural and mesenchymal stem cells, discusses the advances that have been made in the utilization of these stem cells as therapies and in diagnostic imaging (to track the advancement of the stem cells towards the tumor cells), and concludes by addressing various challenges and concerns regarding these therapies.

Normal tissue tolerance for high-grade gliomas: is it an issue?

In this article, we address the currently accepted dose tolerance parameters for the treatment of high-grade gliomas. The issue of normal tissue tolerance is becoming increasingly important because of the long-term survival of a significant subset of young, good performance status patients and the use of hypofractionated regimens for elderly patients with poor performance status. In addition, we address relevant clinical endpoints including clinical, pathologic, and radiographic changes and highlight the difficulty in discriminating between tumor-related and treatment-related effects. Finally, we review relevant clinical trials addressing issues of dose and/or volume parameters. Future trials for patients with high-grade gliomas should consider the inclusion of a prospective evaluation of neurocognitive function and imaging correlates of the brain to assist in the prediction, prevention, and treatment of radiation-induced damage of normal brain tissue.

Persistent outpatient hyperglycemia is independently associated with survival, recurrence and malignant degeneration following surgery for hemispheric low grade gliomas

OBJECTIVE

Hyperglycemia has been shown to augment tumor growth in vitro. However, the effects of persistent hyperglycemia on survival, recurrence and malignant degeneration in patients undergoing surgery for low grade gliomas remain unknown.

METHODS

All patients who underwent a craniotomy for hemispheric low grade glioma (WHO grade II) from 1996 to 2006 at a single institution were retrospectively reviewed. Persistent hyperglycemia was defined as serum glucose >180 microg/dl occurring three or more times between 1 and 3 months post-operatively. The independent association of outpatient glucose levels and recorded clinical and treatment variables with overall survival, tumor recurrence and malignant degeneration was assessed via separate multivariate proportional-hazards regression analyses.

RESULTS

In this study, 182 patients (89 fibrillary astrocytomas, 82 oligodendrogliomas and 11 mixed gliomas) were available for analysis. Eighteen (10%) patients experienced persistent hyperglycemia. Patients experiencing persistent hyperglycemia were older (44 +/- 16 versus 34 +/- 15) and more frequently diabetic [3 (17%) versus 4 (2%)]. All other clinical and treatment variables were not significantly different between the two cohorts. After adjusting for inter-group differences including age and diabetes and variables associated with survival and recurrence, persistent hyperglycemia was independently associated with decreased survival (p=0.001), increased recurrence (p=0.0001) and increased malignant degeneration (p<0.0001). This remained true after excluding all patients with diabetes and those on continued steroid administration. Five-year overall survival, progression-free survival and malignancy-free survival for persistent hyperglycemia versus relatively euglycemic cohorts were 43% versus 84%, 16% versus 46% and 46% versus 77%, respectively.

DISCUSSION

These findings may provide useful insight for increasing survival, decreasing tumor recurrence and decreasing malignant degeneration in patients undergoing surgery for low grade gliomas.

Operative techniques for gliomas and the value of extent of resection

Refinement of neurosurgical technique has enabled safer operations with more aggressive outcomes. One cornerstone of modern-day practice is the utilization of intraoperative stimulation mapping. In addition to identifying critical motor pathways, this technique can be adapted to reliably identify language pathways. Given the individual variability of cortical language localization, such awake language mapping is essential to minimize language deficits following tumor resection. Our experience suggests that cortical language mapping is a safe and efficient adjunct to optimize tumor resection while preserving essential language sites, even in the setting of negative mapping data. However, the value of maximizing glioma resections remains surprisingly unclear, as there is no general consensus in the literature regarding the efficacy of extent of glioma resection in improving patient outcome. While the importance of resection in obtaining tissue diagnosis and alleviating symptoms is clear, a lack of Class I evidence prevents similar certainty in assessing the influence of extent of resection. Beyond an analysis of modern intraoperative mapping techniques, we examine every major clinical publication since 1990 on the role of extent of resection in glioma outcome. The mounting evidence suggests that, despite persistent limitations in the quality of available studies, a more extensive surgical resection is associated with longer life expectancy for both low-grade and high-grade gliomas.

Neurotoxicity of treatment

With the advent of effective treatment regimes increasing survival rates, delayed treatment-related cognitive dysfunction has been recognized as a significant problem. It is considered the most frequent complication among long-term survivors. WBRT may lead to deep brain atrophy and leukoencephalopathy associated with severe cognitive dysfunction, single-fraction dosages of greater than 2 Gy are related to an increased risk of late neurotoxicity, and other factors such as old age, concomitant chemotherapy and preexisting neurological disease increase this risk. However, the potential of focal radiotherapy (RT) with single dosages of 2 Gy or less to a maximal total dose of 60 Gy to produce significant neurotoxicity is less clear. There is a need for a concise neuropsychological test battery to be included in clinical trials, which should meet the following criteria: assess several domains found to be most sensitive to tumor and treatment effects, have standardized stimuli and administration procedures, have published normative data, have moderate to high test-retest reliability, have alternate forms or be relatively insensitive to practice effects, and therefore be suitable to monitor changes in cognitive function over time, include tests that have been translated into several Languages, which can be administered by a trained psychometrician or clinical research associate under supervision of a neuropsychologist, and have a relatively short total administration time. The neuropsychological domains to be evaluated should comprise the cognitive core deficit in brain-tumor patients, namely attention, executive functions (i.e., working memory, processing speed, sequencing abilities), verbal memory, and motor speed.

Phase II study of protracted daily temozolomide for low-grade gliomas in adults

PURPOSE

Resistance to temozolomide chemotherapy is partly mediated by O(6)-methylguanine-DNA methlytransferase (MGMT). Protracted treatment with temozolomide potentially overcomes MGMT resistance and improves outcome. We conducted a phase II study of protracted daily temozolomide in adults with low-grade gliomas.

EXPERIMENTAL DESIGN

Patients with newly diagnosed oligodendroglioma or oligoastrocytoma with a MIB-1 index of >5% or recurrent low-grade gliomas received temozolomide (75 mg/m(2)/day in 11-week cycles of 7 weeks on/4 weeks off). Treatment continued for a total of six cycles or until tumor progression or unacceptable toxicity. Primary end point was best overall response rate; secondary end points were progression-free survival, overall survival, and toxicity. We correlated response with MGMT promoter methylation and chromosome 1p/19q deletion status.

RESULTS

Forty-four patients were treated (14 female, 30 male) with a median follow-up of 39.4 months. Median age was 43 years (range, 20-68 years) and median Karnofsky performance status was 90 (range, 70-100). The regimen was well tolerated. No patients had a complete response (0%), 9 had partial response (20%), 33 had stable disease (75%), and 2 had progressive disease (5%). A total of 21 patients eventually progressed with an overall median progression-free survival of 38 months. Patients with methylated MGMT promoter had a longer overall survival (P = 0.008). Deletion of either 1p or 19q chromosomes also predicted longer overall survival (hazard ratio, 0.17; 95% confidence interval, 0.03-0.93; log-rank P = 0.02).

CONCLUSIONS

A protracted course of daily temozolomide is a well-tolerated regimen and seems to produce effective tumor control. This compares favorably with historical data on the standard 5-day temozolomide regimen.

Adult supratentorial low-grade glioma: long-term experience at a single institution

PURPOSE

To report the long-term follow-up of a cohort of adult patients with supratentorial low-grade glioma treated at a single institution.

METHODS AND MATERIALS

A cohort of 145 adult patients treated at the London Regional Cancer Program between 1979 and 1995 was reviewed.

RESULTS

With a median follow-up of 105 months, the median progression-free survival was 61 months (95% confidence interval, 53-77), and the median overall survival was 118 months (95% confidence interval, 93-129). The 10- and 20-year progression-free and overall survival rate was 18% and 0% and 48% and 22%, respectively. Cox regression analysis confirmed the importance of age, histologic type, presence of seizures, Karnofsky performance status, and initial extent of surgery as prognostic variables for overall and cause-specific survival. Function among long-term survivors without tumor progression was good to excellent for most patients.

CONCLUSION

Low-grade glioma is a chronic disease, with most patients dying of their disease. However, long-term survival with good function is possible. Survival is determined primarily by the disease factors with selection and timing of adjuvant treatments having less influence on outcome.

Cerebral blood volume measurements by perfusion-weighted MR imaging in gliomas: ready for prime time in predicting short-term outcome and recurrent disease?

BACKGROUND AND PURPOSE

Current classification and grading of primary brain tumors has significant limitations. Our aim was to determine whether the relative cerebral volume (rCBV) measurements in gliomas may serve as an adjunct to histopathologic grading, with a hypothesis that rCBV values are more accurate in predicting 1-year survival and recurrence.

MATERIALS AND METHODS

Thirty-four patients with gliomas (WHO grade I-IV, 27 astrocytomas, 7 tumors with oligodendroglial components) underwent contrast-enhanced MR rCBV measurements before treatment. The region of interest and the single pixel with the maximum CBV value within the tumors were normalized relative to the contralateral normal tissue (rCBV(mean) and rCBV(max), respectively). Karnofsky performance score and progression-free survival (PFS) were recorded. Receiver operating characteristic curves and Kaplan-Meier survival analysis were conducted for CBV and histologic grade (WHO grade).

RESULTS

Significant correlations were detected only when patients with oligodendrogliomas and oligoastrocytomas were excluded. The rCBV(mean) and rCBV(max) in the astrocytomas were 3.5 +/- 2.9 and 3.7 +/- 2.7. PFS correlated with rCBV parameters (r = -0.54 to -0.56, P < or = .009). WHO grade correlated with rCBV values (r = 0.65, P < or = .0002). rCBV(max) > 4.2 was found to be a significant cutoff value for recurrence prediction with 77.8% sensitivity and 94.4% specificity (P = .0001). rCBV(max) < or = 3.8 was a significant predictor for 1-year survival (93.7% sensitivity, 72.7% specificity, P = .0002). The relative risk for shorter PFS was 11.1 times higher for rCBV(max) > 4.2 (P = .0006) and 6.7 times higher for WHO grade > II (P = .05). The combined CBV-WHO grade classification enhanced the predictive value for recurrence/progression (P < .0001).

CONCLUSIONS

rCBV values in astrocytomas but not tumors with oligodendroglial components are predictive for recurrence and 1-year survival and may be more accurate than histopathologic grading.

Radiation therapy for visual pathway tumors

The multimodality management of visual pathway tumors frequently involves radiation. Most commonly, photons are delivered via multiple focused beams aimed at the tumor while sparing adjacent tissues. The dose can be delivered in multiple treatments (radiation therapy) or in a single treatment (radiosurgery). Children with visual pathway gliomas should be treated with chemotherapy alone, delaying the use of radiation therapy until progression. Definitive radiation therapy of optic nerve sheath meningiomas results in stable vision in most patients. Radiation therapy or radiosurgery for pituitary tumors can result in control of both tumor growth and hormone hypersecretion. Postoperative radiation therapy or radiosurgery of craniopharyngiomas significantly improves local control rates compared with surgery alone. Radiation therapy is highly effective for eradicating orbital pseudolymphoma and lymphoma. The risk of complications from radiation treatment is dependent on the organ at risk, the cumulative dose it receives, and the dose delivered per fraction.

Surgical management of intracranial gliomas

Surgery is indicated in almost all glioma patients at some point during the course of their disease. The surgical intervention aims at obtaining a tissue diagnosis, providing symptom relief, improving patient survival by reducing the tumor burden, and in rare cases even effecting a cure.A resection will reduce symptoms related to the mass effect of the tumor, and offers a good chance for seizure control. An increasing body of data suggests that glioma patients will benefit from a maximal safe surgical cytoreduction. However, the size of the effect may vary for the different glioma entities. Modern adjuvant neuro-oncological treatment strategies rely heavily on the histological diagnosis. A (stereotactic) biopsy should therefore be offered to patients with nonresectable gliomas to allow for histology-guided adjuvant therapy. Some gliomas can be managed successfully with stereotactic interstitial radiosurgery (brachytherapy). Intra- and extraoperative electrophysiological mapping and/or monitoring, functional MRI, intraoperative imaging, and neuronavigation are increasingly used in many neurosurgical centers in order to reduce surgical morbidity. A definite effect on long-term outcome needs yet to be proven.Advances in computers, imaging, and other technologies will continue to play a large role in the evolution of neurosurgical treatment for gliomas. This may well lead to further centralization of care. There will be an increasing pressure on neurosurgeons to justify the costs involved by showing that patients will actually benefit from complex treatments in highly specialized centers.

Recurrence following neurosurgeon-determined gross-total resection of adult supratentorial low-grade glioma: results of a prospective clinical trial

OBJECT

In 1998, the Radiation Therapy Oncology Group initiated a Phase II study of observation for adults < 40 years old with cerebral low-grade glioma who underwent a neurosurgeon-determined gross-total resection (GTR).

METHODS

Patient eligibility criteria included the presence of a World Health Organization Grade II astrocytoma, oligodendroglioma, or mixed oligoastrocytoma confirmed histologically; age 18-39 years; Karnofsky Performance Scale score > or = 60; Neurologic Function Scale score < or = 3; supratentorial tumor location; neurosurgeon-determined GTR; and pre- and postoperative MR imaging with contrast enhancement available for central review by the principal investigator. Patients were observed following GTR and underwent MR imaging every 6 months. Prognostic factors analyzed for their contribution to patient overall survival, progression-free survival (PFS), and tumor recurrence included age, sex, Karnofsky Performance Scale score, Neurologic Function Scale score, histological type, contrast enhancement on preoperative MR imaging, preoperative tumor diameter, residual disease based on postoperative MR imaging, and baseline Mini-Mental State Examination score.

RESULTS

Between 1998 and 2002, 111 eligible patients were entered into the study. In these 111 patients, the overall survival rates at 2 and 5 years were 99 and 93%, respectively. The PFS rates in these 111 patients at 2 and 5 years were 82 and 48%, respectively. Three prognostic factors predicted significantly poorer PFS in univariate and multivariate analyses: 1) preoperative tumor diameter > or = 4 cm; 2) astrocytoma/oligoastrocytoma histological type; and 3) residual tumor > or = 1 cm according to MR imaging. Review of the postoperative MR imaging results revealed that 59% of patients had < 1 cm residual disease (with a subsequent 26% recurrence rate), 32% had 1-2 cm residual disease (with a subsequent 68% recurrence rate), and 9% had > 2 cm residual disease (with a subsequent 89% recurrence rate).

CONCLUSIONS

These data suggest that young adult patients with low-grade glioma who undergo a neurosurgeon-determined GTR have a > 50% risk of tumor progression 5-years postoperatively, warranting close follow-up and consideration for adjuvant treatment.

Intracranial low-grade gliomas in adults: 30-year experience with long-term follow-up at Mayo Clinic

The purpose of this study was to evaluate long-term survival in patients with nonpilocytic low-grade gliomas (LGGs). Records of 314 adult patients with nonpilocytic LGGs diagnosed between 1960 and 1992 at the Mayo Clinic, Rochester, Minnesota, were retrospectively reviewed. The Kaplan-Meier method estimated progression-free survival (PFS) and overall survival (OS). Median age at diagnosis was 36 years. Median follow-up was 13.6 years. Operative pathology revealed pure astrocytoma in 181 patients (58%), oligoastrocytoma in 99 (31%), and oligodendroglioma in 34 (11%). Gross total resection (GTR) was achieved in 41 patients (13%), radical subtotal resection (rSTR) in 33 (11%), subtotal resection in 130 (41%), and biopsy only in 110 (35%). Median OS was 6.9 years (range, 1 month-38.5 years). Adverse prognostic factors for OS identified by multivariate analysis were tumor size 5 cm or larger, pure astrocytoma histology, Kernohan grade 2, undergoing less than rSTR, and presentation with sensory motor symptoms. Statistically significant adverse prognostic factors for PFS by multivariate analysis were only tumor size 5 cm or larger and undergoing less than rSTR. In patients who underwent less than rSTR, radiotherapy (RT) was associated with improved OS and PFS. A substantial proportion of patients have a good long-term prognosis after GTR and rSTR, with nearly half of patients free of recurrence 10 years after diagnosis. Postoperative RT was associated with improved OS and PFS and is recommended for patients after subtotal resection or biopsy.

Preoperative prognostic classification system for hemispheric low-grade gliomas in adults

Object

Hemispheric low-grade gliomas (LGGs) have an unpredictable progression and overall survival (OS) profile. As a result, the objective in the present study was to design a preoperative scoring system to prognosticate long-term outcomes in patients with LGGs.

Methods

The authors conducted a retrospective review with long-term follow-up of 281 adults harboring hemispheric LGGs (World Health Organization Grade II lesions). Clinical and radiographic data were collected and analyzed to identify preoperative predictors of OS, progression-free survival (PFS), and extent of resection (EOR). These variables were used to devise a prognostic scoring system.

Results

The 5-year estimated survival probability was 0.86. Multivariate Cox proportional hazards modeling demonstrated that 4 factors were associated with lower OS: presumed eloquent location (hazard ratio [HR] 4.12, 95% confidence interval [CI] 1.71–10.42), Karnofsky Performance Scale score ≤ 80 (HR 3.53, 95% CI 1.56–8.00), patient age > 50 years (HR 1.96, 95% CI 1.47–3.77), and tumor diameter > 4 cm (HR 3.43, 95% CI 1.43–8.06). A scoring system calculated from the sum of these factors (range 0–4) demonstrated risk stratification across study groups, with the following 5-year cumulative survival estimates: Scores 0–1, OS = 0.97, PFS = 0.76; Score 2, OS = 0.81, PFS = 0.49; and Scores 3–4, OS = 0.56, PFS = 0.18 (p < 0.001 for both OS and PFS, log-rank test). This proposed scoring system demonstrated a high degree of interscorer reliability (kappa = 0.86). Four illustrative cases are described.

Conclusions

The authors propose a simple and reliable scoring system that can be used to preoperatively prognosticate the degree of lesion resectability, PFS, and OS in patients with LGGs. The application of a standardized scoring system for LGGs should improve clinical decision-making and allow physicians to reliably predict patient outcome at the time of the original imaging-based diagnosis.

EXTENT OF SURGICAL RESECTION IS INDEPENDENTLY ASSOCIATED WITH SURVIVAL IN PATIENTS WITH HEMISPHERIC INFILTRATING LOW-GRADE GLIOMAS

OBJECTIVE

It remains unknown whether the extent of surgical resection affects survival or disease progression in patients with supratentorial low-grade gliomas.

METHODS

We conducted a retrospective cohort study (n = 170) between 1996 and 2007 at a single institution to determine whether increasing extent of surgical resection was associated with improved progression-free survival (PFS) and overall survival (OS). Surgical resection of gliomas defined as gross total resection (GTR) (complete resection of the preoperative fluid-attenuated inversion recovery signal abnormality), near total resection (NTR) (&lt;3-mm thin residual fluid-attenuated inversion recovery signal abnormality around the rim of the resection cavity only), or subtotal resection (STR) (residual nodular fluid-attenuated inversion recovery signal abnormality) based on magnetic resonance imaging performed less than 48 hours after surgery. Our main outcome measures were OS, PFS, and malignant degeneration-free survival (conversion to high-grade glioma).

RESULTS

One hundred thirty-two primary and 38 revision resections were performed for low-grade astrocytomas (n = 93) or oligodendrogliomas (n = 77). GTR, NTR, and STR were achieved in 65 (38%), 39 (23%), and 66 (39%) cases, respectively. GTR versus STR was independently associated with increased OS (hazard ratio, 0.36; 95% confidence interval, 0.16–0.84; P = 0.017) and PFS (HR, 0.56; 95% confidence interval, 0.32–0.98; P = 0.043) and a trend of increased malignant degeneration-free survival (hazard ratio, 0.46; 95% confidence interval, 0.20–1.03; P = 0.060). NTR versus STR was not independently associated with improved OS, PFS, or malignant degeneration-free survival. Five-year OS after GTR, NTR, and STR was 95, 80, 70%, respectively, and 10-year OS was 76, 57, and 49%, respectively. After GTR, NTR, and STR, median time to tumor progression was 7.0, 4.0, and 3.5 years, respectively. Median time to malignant degeneration after GTR, NTR, and STR was 12.5, 5.8, and 7 years, respectively.

CONCLUSION

GTR was associated with a delay in tumor progression and malignant degeneration as well as improved OS independent of age, degree of disability, histological subtype, or revision versus primary resection. GTR should be safely attempted when not limited by eloquent cortex.

North Central Cancer Treatment Group--achievements and perspectives

The North Central Cancer Treatment Group (NCCTG) was founded in 1977 as a regional cooperative group to allow cancer patients in the upper Midwest of the United States to gain access to clinical trials in oncology by establishing a network of community oncology practices with one academic research base, the Mayo Clinic. Since then, the NCCTG has grown into an international cooperative group with 43 members in 33 US states and Canada. This article details 30 years of achievements of the NCCTG, including important scientific contributions from disease-specific and treatment modality committees, the cancer control program, patient-reported outcomes and quality-of-life research, and biostatisticians that support the NCCTG's specific aims: to improve the duration and quality of life of cancer patients, to enhance our understanding of the biological consequences of cancer and its treatment, and to improve methods for clinical trial conduct.

Phase II study of carboplatin and erlotinib (Tarceva, OSI-774) in patients with recurrent glioblastoma

Targeting the epidermal growth factor receptor (EGFR) may be effective in a subset of glioblastoma patients. This phase II study assessed the clinical activity of erlotinib plus carboplatin and to determine molecular predictors of response. The primary endpoint was progression free survival (PFS). Patients with recurrent glioblastoma with no more than two prior relapses received carboplatin intravenously on day 1 of every 28-day cycle (target AUC of 6 mg x ml/min). Daily erlotinib at 150 mg/day was dose escalated to 200 mg/day, as tolerated. Clinical and MRI assessments were made every 4 and 8 weeks, respectively. Tumor tissue was evaluated for EGFR, AKT and phosphatase and tensin homolog (PTEN) status. One partial response (PR) was observed out of 43 assessable patients. Twenty patients (47%) had stable disease (SD) for an average of 12 weeks. Median PFS was 9 weeks. The 6-month PFS rate was 14%. Median overall survival (OS) was 30 weeks. This regimen was well tolerated with grade 3/4 toxicities of fatigue, leukopenia, thrombocytopenia and rash requiring dose reductions. A recursive partitioning analysis (RPA) predicted that patients with KPS >or=90 treated with more than 1 prior regimen had the highest OS. No correlation was observed between EGFR, Akt or PTEN expression and either PFS or OS. Carboplatin plus erlotinib is well tolerated but has modest activity in unselected patients. Future trials should be stratified based on optimal molecular or clinical characteristics.

Quality of life in low-grade glioma patients receiving temozolomide

The purpose of this study was to describe the quality of life (QOL) of low-grade glioma (LGG) patients at baseline prior to chemotherapy and through 12 cycles of temozolomide (TMZ) chemotherapy. Patients with histologically confirmed LGG with only prior surgery were given TMZ for 12 cycles. QOL assessments by the Functional Assessment of Cancer Therapy-Brain (FACT-Br) were obtained at baseline prior to chemotherapy and at 2-month intervals while receiving TMZ. Patients with LGG at baseline prior to chemotherapy had higher reported social well-being scores (mean difference = 5.0; p < 0.01) but had lower reported emotional well-being scores (mean difference = 2.2; p < 0.01) compared to a normal population. Compared to patients with left hemisphere tumors, patients with right hemisphere tumors reported higher physical well-being scores (p = 0.01): 44% could not drive, 26% did not feel independent, and 26% were afraid of having a seizure. Difficulty with work was noted in 24%. Mean change scores at each chemotherapy cycle compared to baseline for all QOL subscales showed either no significant change or were significantly positive (p < 0.01). Patients with LGG on TMZ at baseline prior to chemotherapy reported QOL comparable to a normal population with the exception of social and emotional well-being, and those with right hemisphere tumors reported higher physical well-being scores compared to those with left hemisphere tumors. While remaining on therapy, LGG patients were able to maintain their QOL in all realms. LGG patients' QOL may be further improved by addressing their emotional well-being and their loss of independence in terms of driving or working.

Glioma extent of resection and its impact on patient outcome

OBJECTIVE

There is still no general consensus in the literature regarding the role of extent of glioma resection in improving patient outcome. Although the importance of resection in obtaining tissue diagnosis and alleviating symptoms is clear, a lack of Class I evidence prevents similar certainty in assessing the influence of extent of resection.

METHODS

We reviewed every major clinical publication since 1990 on the role of extent of resection in glioma outcome.

RESULTS

Twenty-eight high-grade glioma articles and 10 low-grade glioma articles were examined in terms of quality of evidence, expected extent of resection, and survival benefit.

CONCLUSION

Despite persistent limitations in the quality of data, mounting evidence suggests that more extensive surgical resection is associated with longer life expectancy for both low- and high-grade gliomas.

Preoperative functional magnetic resonance imaging assessment of higher-order cognitive function in patients undergoing surgery for brain tumors

OBJECT

Resection of brain tumors has been shown to increase patient survival. The extent of the possible resection, however, depends on whether the tumor has invaded brain regions important for motor, sensory, or cognitive processes and whether the brain tissue surrounding the tumor maintains its functional role. The goal of the present study was to develop new pre- and intraoperative tools to specifically assess the function of the rostral part of the dorsal premotor cortex (PMdr) in 4 patients with brain tumors close to this region.

METHODS

Using functional magnetic resonance (fMR) imaging and a task developed to assess accurate selection between competing responses based on conditional rules, the authors preoperatively assessed the function of the PMdr in 4 patients with brain tumors close to this region. In 1 patient, the authors developed an intraoperative procedure to assess performance on the task during the tumor resection.

RESULTS

Preoperative fMR imaging data showed specific activity increases in the vicinity of the tumors, that is, in the PMdr. As confirmed by postoperative structural MR imaging, the extent of the tumor resection was optimal and the functional region within the PMdr was preserved. Furthermore, patients exhibited no postoperative deficits during task performance, demonstrating that the function was preserved. Intraoperative behavioral results demonstrated that the cognitive processes underlying performance on the task remained intact throughout the tumor resection.

CONCLUSIONS

These findings suggest that preoperative fMR imaging, together with intraoperative behavioral evaluation, may be a useful paradigm to assist neurosurgeons in preserving cognitive function in patients with brain tumors.

Management of glioblastoma

Glioblastoma multiforme (GBM) are among the most devastating neoplasms claiming the lives of patients within a median of 1 year after diagnosis. Treatment of GBM requires a multidisciplinary approach. Treatments include surgery, radiotherapy, chemotherapy and so on. Temozolomide (TMZ) has emerged as an active agent against malignant gliomas. On the basis of the work by the European Organisation for Research and Treatment of Cancer/National Cancer Institute of Canada, concurrent radiotherapy and the oral alkylating agent TMZ followed by adjuvant TMZ has become the standard of care for patients with newly diagnosed GBM, although the methylation status of the O(6)-mehylguanine-DNA methyltransferase promoter is predictive for survival of GBM patients. Gliadel is a biodegradable polymer wafer impregnated with carmustine. Gliadel has been one of the few treatment modalities to demonstrate a statistical benefit in patients with malignant glioma. These new FDA approved drugs advanced the treatment of malignant glioma, but more progress is needed. Patients require improvements in chemotherapy, surgery, radiotherapy, molecular targeted therapy, immunotoxin using the convection-enhanced delivery and more.