Challenges relating to solid tumour brain metastases in clinical trials, part 2: neurocognitive, neurological, and quality-of-life outcomes. A report from the RANO group

Neurocognitive function, neurological symptoms, functional independence, and health-related quality of life are major concerns for patients with brain metastases. The inclusion of these endpoints in trials of brain metastases and the methods by which these measures are assessed vary substantially. If functional independence or health-related quality of life are planned as key study outcomes, then the reliability and validity of these endpoints can be crucial because methodological issues might affect the interpretation and acceptance of findings. The Response Assessment in Neuro-Oncology (RANO) working group is an independent, international, and collaborative effort to improve the design of clinical trials in patients with brain tumours. In this report, the second in a two-part series, we review clinical trials of brain metastases in relation to measures of clinical benefit and provide a framework for the design and conduct of future trials.

A phase II study of a temozolomide-based chemoradiotherapy regimen for high-risk low-grade gliomas: Preliminary results of RTOG 0424

2008

Background: The primary endpoint of RTOG 0424 was to compare the 3-year survival (OS) of a regimen of concurrent and adjuvant temozolomide (TMZ) and radiotherapy (RT) in a high-risk low-grade glioma (LGG) population to the 3 year (yr) OS rate of the high risk EORTC LGG patients (pts) reported by Pignatti et al (J Clin Oncol 2002;20(8):2076-84). Secondary endpoints were: progression-free survival (PFS), toxicity, neurocognitive and quality of life data and molecular analysis. Methods: Pts with LGG's and >=3 high risk factors (age> = 40, astrocytoma dominant histology, tumor crossing midline, tumor > = 6 cm or preoperative neurological function status >1) were eligible and treated with conformal RT (54 Gy/30 fractions) plus concurrent TMZ 75 mg/m2 /day for 6 weeks and post-RT TMZ 150-200 mg/m2/day days 1-5 q28 days for up to 12 cycles. The 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 yr OS rate from 54% to 65%, at a 10% significance level (1 sided) and 96% power. Results: Between January 2005-August 2009 136 pts were accrued, 129 (75 males, 54 females) were evaluable. Median age was 49 years, 91% had a Zubrod score 0-1 and 69%, 25% and 6% of pts had 3,4 and 5 high risk factors respectively. With a median follow-up time of 4.1 yrs, minimum follow-up of 3 yrs, MST has not yet been reached. Three year OS rate was 73.1% (95%CI:65.3-80.8%), significantly improved from historical control with a p-value <0.0001. No difference in OS rates for pts with 3, 4 or 5 high risk factors was seen. 3 year PFS was 59.2% (95% CI:50.7-67.8%). Grade 3 adverse events (AE) occurred in 43% of pts and grade 4 AE in 10%, primarily hematologic, constitutional or gastrointestinal (nausea, anorexia) toxicity. One patient died of herpes encephalitis. Secondary analyses are ongoing. Radiation Quality Assurance was per protocol/ acceptable in 95% and 74% of pts completed chemotherapy per protocol. Conclusions: The 3 year OS rate of 73.1% for these high risk LGG pts is significantly higher than those reported for historical controls (54%, p < 0.0001, one-sided) and the study-hypothesized 65%. Supported by RTOG U10 CA21661 and CCOP U10 CA37422 grants from NCI and Merck Clinical trial information: NCT00114140.

Phase II study of PX-866 in recurrent glioblastoma

2053

Background: Glioblastoma (GBM) is the most aggressive malignancy of the central nervous system. The majority have genetic changes that increase the activity of the phosphatidylinositol-3-OH kinase (PI3K) signal transduction pathway, critical for cell motility, proliferation, and survival. We present the results of PX-866, an oral PI3K inhibitor, in patients (pts) with recurrent GBM. Methods: A multinomial design of response and early progression (< 8 weeks on study) was used. In stage 1 (15 pts), 0 responses and ≥ 10 early progressions would stop accrual; after full accrual, ≥ 4 responses OR ≤ 13 early progressions was prespecified as of interest. Pts with histologically confirmed GBM, at first recurrence after chemoradiation and adjuvant temozolomide were given PX-866 8 mg daily on this single-arm phase II study. MRI and clinical exam were done every cycle (8 weeks). Tumour tissue was collected for analysis of potential markers of PI3K inhibitory activity (PTEN, EGFRviii, PIK3CA mutations). Results: A total of 33 pts were enrolled, eligible and evaluable. Median age was 56 (range 35-78), 12 were female; 29 had performance status (PS) 0-1 and 4 had PS 2. Median time from initial diagnosis to enrolment was 308 days (range 141-1256). Median number of cycles was 1 (range 1-7). Thirty-two pts have discontinued therapy, 26 due to disease/symptomatic progression and 6 due to toxicity (5 LFT elevation and 1 allergic reaction). Other adverse effects (AE): fatigue (16 pts/2 grade 3), diarrhea (11 pts/5 grade 3), nausea (19 pts/1 grade 3), vomiting (11 pts/1 grade 3) and lymphopenia (29 pts/7 grade 3/4). Five pts had related serious AEs (1 LFTs, 1 GI and 3 venous thromboembolism) All pts were evaluable for response; 25 had a best response of progression, 1 had partial response (overall response rate 3%) and seven (21%) had stable disease (SD, median 7.3 months; range 3.1-13.6). Six month PFS was 17%. In preliminary analyses, no statistical association was found between SD and PTEN or EGFRviii status (results pending in 16 pts). Conclusions: PX-866 was relatively well tolerated. Overall response rate was low, and the study did not meet its primary endpoint; however, 21% of pts obtained durable stable disease. Further correlative work is required to identify the predictor of this effect. Clinical trial information: NCT01259869.

Low-grade gliomas in children: tumor volume response to radiation

Object. The authors conducted a retrospective review to examine and document the frequency, degree, and timing of the radiologically confirmed response to radiotherapy of low-grade gliomas in children. Methods. Between 1963 and 1995, 80 patients 17 years of age or younger were referred to the London Regional Cancer Centre in London, Ontario, after diagnosis of a low-grade glioma. All patients underwent surgical resection or biopsy procedures and 47 underwent radiotherapy (40 postoperatively and seven at the time of tumor progression). Nineteen patients with residual measurable lesions who received radiation therapy were selected for volumetric analysis of tumor response to this treatment. The extent and timing of response to radiation were determined by the process of comparing postoperative, preirradiation computerized tomography (CT) scans with postirradiation, follow-up CT scans. For one patient the comparison was made by using serial magnetic resonance images. Residual tumor was found on postoperative CT scans in all cases. The mean preradiotherapy tumor volume was 17.1 cm(3), and the postradiotherapy volume was reduced to a mean of 11.5 cm(3). A reduction in tumor was demonstrated in eight patients by the time of their first postirradiation follow-up CT scan and in two patients a slower reduction in volume over time was shown, bringing the total number of "responders" to 10. In five of these 10 patients the tumor had shown a maximum response by the time of the first postirradiation CT scan; the median time to response was 3.3 months. A 25% or greater reduction in tumor volume was seen in eight (42%) of the 19 patients. A 50% or greater reduction was noted in five (26%) of the patients. A complete response was demonstrated at 7, 12, and 15 months, and 5 years, respectively, in four patients (21%). One responder's tumor eventually increased in size after radiotherapy and he died of his disease. The magnitude of the radiographically demonstrated response to radiation did not correlate significantly with clinical outcome (that is, survival or symptom improvement). Conclusions. On the basis of this CT scan analysis of the response of low-grade gliomas in children to radiotherapy, the authors suggest that these lesions respond to radiation, as demonstrated by tumor shrinkage on serial imaging. Major or complete responses occur occasionally. However, low-grade gliomas in children mimic other benign brain tumors such as pituitary adenomas and meningiomas in that, although growth is frequently arrested after radiotherapy, residual tumor can persist for many years, illustrating that tumor shrinkage may not be a good measure of treatment efficacy. Nevertheless, radiation therapy can result in improvement of clinical symptomatology in association with or independent of visible tumor reduction. As radiation treatment techniques become increasingly conformal and because studies indicate that lower doses of radiation may be equally effective, improvement of symptoms may be an important consideration when weighing treatment options, particularly in patients with residual or unresectable disease.

Phase II study of PX-866 in recurrent glioblastoma

2051

Background: Glioblastoma (GBM) is the most aggressive malignancy of the central nervous system. The majority of GBM have genetic changes that increase the activity of the phosphatidylinositol-3-OH kinase (PI3K) signal transduction pathway, critical for cell motility, proliferation, and survival. We present the interim results of PX-866, an oral PI3K inhibitor, in patients (pts) with recurrent GBM. Methods: Pts with histologically confirmed GBM at first recurrence after treatment with chemoradiation and adjuvant temozolomide are given PX-866 8 mg daily on this single-arm phase II study. MRI and clinical exam are done every 8 weeks to determine treatment response. The trial has a 2-stage design with dual endpoints of objective response and early progression (within 8 weeks). In Stage I, 15 pts are evaluated and if 0 responses and 10 or more early progressions are seen, enrolment will stop. Otherwise, Stage II will enrol another 15 pts for efficacy analysis. Tumour tissue is collected for analysis of potential markers of PI3K inhibitory activity (PTEN, EGFRvIII, PIK3CA mutations). Results: Seventeen pts have been enroled to date: 14 evaluable for response and 15 for toxicity. Median age was 54 years (range 35-70), with 7 females and 10 males. No pts had received treatment for recurrent GBM, and median time between initial diagnosis and study enrolment was 300 days (range: 113-447 days). Pts have received a median of one 8-week cycle of PX-866 (range: 1-4). Twelve pts have discontinued therapy, 9 due to disease progression and 3 due to grade 3/4 liver enzyme abnormalities. Other adverse effects have included fatigue (10 pts/1 grade 3), diarrhea (6 pts/3 grade 3), nausea (7 pts/0 grade 3), vomiting (6 pts/0 grade 3), lymphopenia (14 pts/3 grade 3). Stage I response data are premature; it is not yet known if the trial will continue to Stage II. Archival tissue is available on all patients and is undergoing analysis. Conclusions: This is one of the first trials of a PI3K inhibitor in pts with recurrent GBM. PX-866 has been relatively well tolerated. Stage I response data are premature; while it is not yet known if the criteria will be met to continue to Stage II, prolonged SD has been observed in some pts. The correlative biomarker assays underway will be important to understand this observation.

Prolonged survival with valproic acid use in the EORTC/NCIC temozolomide trial for glioblastoma

OBJECTIVE

This analysis was performed to assess whether antiepileptic drugs (AEDs) modulate the effectiveness of temozolomide radiochemotherapy in patients with newly diagnosed glioblastoma.

METHODS

The European Organization for Research and Treatment of Cancer (EORTC) 26981-22981/National Cancer Institute of Canada (NCIC) CE.3 clinical trial database of radiotherapy (RT) with or without temozolomide (TMZ) for newly diagnosed glioblastoma was examined to assess the impact of the interaction between AED use and chemoradiotherapy on survival. Data were adjusted for known prognostic factors.

RESULTS

When treatment began, 175 patients (30.5%) were AED-free, 277 (48.3%) were taking any enzyme-inducing AED (EIAED) and 135 (23.4%) were taking any non-EIAED. Patients receiving valproic acid (VPA) only had more grade 3/4 thrombopenia and leukopenia than patients without an AED or patients taking an EIAED only. The overall survival (OS) of patients who were receiving an AED at baseline vs not receiving any AED was similar. Patients receiving VPA alone (97 [16.9%]) appeared to derive more survival benefit from TMZ/RT (hazard ratio [HR] 0.39, 95% confidence interval [CI] 0.24-0.63) than patients receiving an EIAED only (252 [44%]) (HR 0.69, 95% CI 0.53-0.90) or patients not receiving any AED (HR 0.67, 95% CI 0.49-0.93).

CONCLUSIONS

VPA may be preferred over an EIAED in patients with glioblastoma who require an AED during TMZ-based chemoradiotherapy. Future studies are needed to determine whether VPA increases TMZ bioavailability or acts as an inhibitor of histone deacetylases and thereby sensitizes for radiochemotherapy in vivo.

Neurocytomas: long-term experience of a single institution

There is a lack of studies reporting on outcomes of control and treatment toxicities for neurocytomas. A 25-year retrospective review of a tertiary center's experience with neurocytomas was completed to report on these outcomes. All cerebral neurocytoma cases (19 patients; median age, 31 years; range, 18-62 years; 18 intraventricular and 1 extraventricular) treated between 1984 and 2009 were analyzed, including central pathology and radiology reviews. Median follow-up was 104.5 months (range, 0.75-261.7 months). Primary treatment was surgery alone (n = 18 patients), followed by surgery and adjuvant radiotherapy (n = 1). The crude local control rate after surgery was 68% for all cases (cerebral neurocytomas) and 74% for central neurocytomas. Salvage therapies included further surgery (n = 4), radiation (n = 3), and chemotherapy (n = 1). Ten-year Kaplan-Meier overall and relapse-free survival rates were 82% and 62% and 81% and 57%, respectively, for all cases and for central neurocytomas only. The median overall survival and relapse-free survival were 104.5 and 79.3 months, respectively, for all cases and for central neurocytomas. Ten patients had grade 3/4 toxicity, and 1 patient had a grade 5 perioperative hemorrhage that resulted in death 23 days after surgery. Late grade 3/4 toxicities occurred in 9 patients. Three patients had permanent grade 2 motor or cognitive deficits. We provide the first report outlining toxicities and survival outcomes in a series of 19 patients. Our experience suggests that initial surgery provides durable local control rates in two-thirds of patients, with low risk for significant permanent deficits. Salvage therapy with surgery and/or radiation provides durable local control in tumors that recur after surgery.

Evidence for consistency of the glycation gap in diabetes

OBJECTIVE

Discordance between HbA(1c) and fructosamine estimations in the assessment of glycemia is often encountered. A number of mechanisms might explain such discordance, but whether it is consistent is uncertain. This study aims to coanalyze paired glycosylated hemoglobin (HbA(1c))-fructosamine estimations by using fructosamine to determine a predicted HbA(1c), to calculate a glycation gap (G-gap) and to determine whether the G-gap is consistent over time.

RESEARCH DESIGN AND METHODS

We included 2,263 individuals with diabetes who had at least two paired HbA(1c)-fructosamine estimations that were separated by 10 ± 8 months. Of these, 1,217 individuals had a third pair. The G-gap was calculated as G-gap = HbA(1c) minus the standardized fructosamine-derived HbA(1c) equivalent (FHbA(1c)). The hypothesis that the G-gap would remain consistent in individuals over time was tested.

RESULTS

The G-gaps were similar in the first, second, and third paired samples (0.0 ± 1.2, 0.0 ± 1.3, and 0.0 ± 1.3, respectively). Despite significant changes in the HbA(1c) and fructosamine, the G-gap did not differ in absolute or relative terms and showed no significant within-subject variability. The direction of the G-gap remained consistent.

CONCLUSIONS

The G-gap appears consistent over time; thus, by inference any key underlying mechanisms are likely to be consistent. G-gap calculation may be a method of exploring and evaluating any such underlying mechanisms.

Application of Novel Response/Progression Measures for Surgically Delivered Therapies for Gliomas

BACKGROUND

The Response Assessment in Neuro-Oncology (RANO) Working Group is an international, multidisciplinary effort to develop new standardized response criteria for clinical trials in brain tumors. The RANO group identified knowledge gaps relating to the definitions of tumor response and progression after the use of surgical or surgically based treatments.

OBJECTIVE

To outline a proposal for new response and progression criteria for the assessment of the effects of surgery and surgically delivered therapies for patients with gliomas.

METHODS

The Surgery Working Group of RANO identified surgically related end-point evaluation problems that were not addressed in the original Macdonald criteria, performed an extensive literature review, and used a consensus-building process to develop recommendations for how to address these issues in the setting of clinical trials.

RESULTS

Recommendations were formulated for surgically related issues, including imaging changes associated with surgical resection or surgically mediated adjuvant local therapies, the determination of progression in the setting where all enhancing tumor has been removed, and how new enhancement should be interpreted in the setting where local therapies that are known to produce nonspecific enhancement have been used. Additionally, the terminology used to describe the completeness of surgical resections has been recognized to be inconsistently applied to enhancing vs nonenhancing tumors, and a new set of descriptors is proposed.

CONCLUSION

The RANO process is intended to produce end-point criteria for clinical trials that take into account the effects of prior and ongoing therapies. The RANO criteria will continue to evolve as new therapies and technologies are introduced into clinical trial and/or practice.

Clinical trial end points for high-grade glioma: the evolving landscape

To review the strengths and weaknesses of primary and auxiliary end points for clinical trials among patients with high-grade glioma (HGG). Recent advances in outcome for patients with newly diagnosed and recurrent HGG, coupled with the development of multiple promising therapeutics with myriad antitumor actions, have led to significant growth in the number of clinical trials for patients with HGG. Appropriate clinical trial design and the incorporation of optimal end points are imperative to efficiently and effectively evaluate such agents and continue to advance outcome. Growing recognition of limitations weakening the reliability of traditional clinical trial primary end points has generated increasing uncertainty of how best to evaluate promising therapeutics for patients with HGG. The phenomena of pseudoprogression and pseudoresponse have made imaging-based end points, including overall radiographic response and progression-free survival, problematic. Although overall survival is considered the "gold-standard" end point, recently identified active salvage therapies such as bevacizumab may diminish the association between presalvage therapy and overall survival. Finally, advances in imaging as well as the assessment of patient function and well being have strengthened interest in auxiliary end points assessing these aspects of patient care and outcome. Better appreciation of the strengths and limitations of primary end points will lead to more effective clinical trial strategies. Technical advances in imaging as well as improved survival for patients with HGG support the further development of auxiliary end points evaluating novel imaging approaches as well as measures of patient function and well being.

Phase II Trial of Continuous Dose-Intense Temozolomide in Recurrent Malignant Glioma: RESCUE Study

Purpose

Concomitant temozolomide (TMZ)/radiotherapy followed by adjuvant TMZ has increased survival in patients with glioblastoma multiforme (GBM). However, few options are effective for patients who experience treatment failure. We conducted a multicenter, phase II study to assess the efficacy and safety of continuous dose-intense TMZ for recurrent GBM.

Patients and Methods

Patients with malignant glioma at progression after standard TMZ 150 to 200 mg/m2 × 5 days in a 28-day cycle for three or more cycles were stratified by tumor type (anaplastic glioma group A, GBM, group B). Ninety-one patients with GBM were prospectively divided into three groups (early [B1], extended [B2], and rechallenge [B3]) according to the timing of progression during adjuvant therapy. All patients received continuous dose-intense TMZ 50 mg/m2/d for up to 1 year or until progression occurred. Response was assessed by using RECIST (Response Evaluation Criteria in Solid Tumors).

Results

A total of 116 of 120 patients were evaluable for efficacy. For patients with GBM, 6-month progression-free survival (PFS) was 23.9% (B1, 27.3%; B2, 7.4%; B3, 35.7%). One-year survival from time of study entry was 27.3%, 14.8%, and 28.6% for the B1, B2 and B3 groups, respectively. For patients with anaplastic glioma, 6-month PFS was 35.7%; 1-year survival was 60.7%. The most common grades 3 and 4 nonhematologic toxicities were nausea/vomiting (6.7%) and fatigue (5.8%). Grades 3 and 4 hematologic toxicities were uncommon.

Conclusion

Rechallenge with continuous dose-intense TMZ 50 mg/m2/d is a valuable therapeutic option for patients with recurrent GBM. Patients who experience progression during the first six cycles of conventional adjuvant TMZ therapy or after a treatment-free interval get the most benefit from therapy.

Updated response assessment criteria for high-grade gliomas: response assessment in neuro-oncology working group

Currently, the most widely used criteria for assessing response to therapy in high-grade gliomas are based on two-dimensional tumor measurements on computed tomography (CT) or magnetic resonance imaging (MRI), in conjunction with clinical assessment and corticosteroid dose (the Macdonald Criteria). It is increasingly apparent that there are significant limitations to these criteria, which only address the contrast-enhancing component of the tumor. For example, chemoradiotherapy for newly diagnosed glioblastomas results in transient increase in tumor enhancement (pseudoprogression) in 20% to 30% of patients, which is difficult to differentiate from true tumor progression. Antiangiogenic agents produce high radiographic response rates, as defined by a rapid decrease in contrast enhancement on CT/MRI that occurs within days of initiation of treatment and that is partly a result of reduced vascular permeability to contrast agents rather than a true antitumor effect. In addition, a subset of patients treated with antiangiogenic agents develop tumor recurrence characterized by an increase in the nonenhancing component depicted on T2-weighted/fluid-attenuated inversion recovery sequences. The recognition that contrast enhancement is nonspecific and may not always be a true surrogate of tumor response and the need to account for the nonenhancing component of the tumor mandate that new criteria be developed and validated to permit accurate assessment of the efficacy of novel therapies. The Response Assessment in Neuro-Oncology Working Group is an international effort to develop new standardized response criteria for clinical trials in brain tumors. In this proposal, we present the recommendations for updated response criteria for high-grade gliomas.

End point assessment in gliomas: novel treatments limit usefulness of classical Macdonald's Criteria

Recent trials in glioma have revealed significant limitations in the end points used. This requires a critical and comprehensive review of how brain tumor trials are conducted, particularly of which end points are defined and how response and progression are defined.

Clinical impact of variability in HbA1c as assessed by simultaneously measuring fructosamine and use of error grid analysis

BACKGROUND

Haemoglobin A1c (HbA1c) is the only measure of glycaemic control used for many patients with diabetes, but it has limitations and might sometimes be misleading. HbA(1c) concentrations are influenced by conditions that alter red-cell life and there is evidence that biochemical variation in intracellular glycation rates also influence HbA1c concentrations. This paper is the first to propose a method of using simultaneously measured HbA1c and fructosamine, and error grid analysis, in the clinical setting, to gain a better understanding of glycaemic control.

METHODS

Cross-sectional analytical study using HbA1c and fructosamine measures on the same blood sample from 1744 patients having blood taken for hospital diabetes clinic appointments. No other selection or exclusion criteria were applied.

RESULTS

The fructosamine results were converted to a HbA1c equivalent which was then compared with the HbA1c. In an Altman-Bland plot, the paired result differences ranged between -6.9% and +5.5% HbA1c with 1139 (65%), 438 (25%), 130 (8%) and 37 (2%) being < or =1%, 1-2%, 2-3% or >3% of HbA1c difference, respectively. In clinical error grid analysis, 864 (50%) results had tight concordance for clinical interpretation, 761 (43%) had one block disunity of probably little clinical significance, but 105 (6%) were two blocks and 14 (1%) were three blocks discordant.

CONCLUSION

HbA1c may not accurately reflect glucose control. Our method, utilizing co-assessment with serum fructosamine, evaluates the possible clinical impact of this. We suggest the analysis used in this paper should be used routinely in diabetes practice.

High-dose chemotherapy with stem cell rescue as initial therapy for anaplastic oligodendroglioma: long-term follow-up

We previously reported a phase 2 trial of 69 patients with newly diagnosed anaplastic or aggressive oligodendroglioma who were treated with intensive procarbazine, CCNU (lomustine), and vincristine (PCV) followed by high-dose thiotepa with autologous stem cell rescue. This report summarizes the long-term follow-up of the cohort of 39 patients who received high-dose thiotepa with autologous stem cell support. Thirty-nine patients with a median age of 43 (range, 18-67) and a median KPS of 100 (range, 70-100) were treated. Surviving patients now have a median follow-up of 80.5 months (range, 44-142). The median progression-free survival is 78 months, and median overall survival has not been reached. Eighteen patients (46%) have relapsed. Neither histology nor prior low-grade oligodendroglioma correlated with risk of relapse. Persistent nonenhancing tumor at transplant was identified in our initial report as a significant risk factor for relapse; however, long-term follow-up has not confirmed this finding. Long-term neurotoxicity has developed only in those patients whose disease relapsed and required additional therapy; no patient in continuous remission has developed a delayed neurologic injury. This treatment strategy affords long-term disease control to a subset of patients with newly diagnosed anaplastic oligodendroglioma without evidence of delayed neurotoxicity or myelodysplasia.

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

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

New frontiers in the treatment of malignant glioma

Despite many technologic advances in neuroimaging, neurosurgery, and radiation therapy, there has been little improvement in survival for patients with malignant glioma. Given the failure of traditional treatment approaches to significantly improve survival in patients with malignant gliomas, research in this field has focused on gaining a better understanding of the molecular pathogenesis of gliomas with the goal of identifying novel drug targets and therapeutic strategies. The influence of molecular genetics on response and survival has been best shown in oligodendrogliomas. The hallmarks of low-grade and anaplastic oligodendrogliomas are their exquisite sensitivity to chemotherapy and favorable prognosis, which are correlated with loss of heterozygosity of chromosomes 1p and 19q. Together, loss of heterozygosity of 1p and 19q appears to confer responsiveness to chemotherapy and to correlate with improved survival. In contrast, deletion of the CDKN2A gene is correlated with poor response to chemotherapy and poor survival, and loss of heterozygosity of chromosome 10q is associated with shorter progression-free and overall survival compared with intact 10q. A variety of other molecular genetic abnormalities have been recognized in gliomas, and these genetic changes are not only important prognostic factors, but also offer new therapeutic targets. With the increased use of improved surgical and radiotherapy techniques and targeted biologic therapy over the next 20 years, many patients with malignant gliomas may be cured or their disease may be controlled for the long term. Molecular profiling of patients using gene chip technology will likely become commonplace, and many patients will receive a tailored treatment regimen based on the unique genetic profile of their tumor.

High-dose Chemotherapy with Stem Cell Rescue as Initial Therapy for Anaplastic Oligodendroglioma

PURPOSE

Anaplastic oligodendroglioma is a chemosensitive glial neoplasm. To improve disease control and postpone cranial radiotherapy, we designed a phase II study of intensive procarbazine, lomunstine and vincristine followed by high-dose thiotepa with autologous stem cell rescue for patients with newly diagnosed anaplastic or aggressive oligodendroglioma.

PATIENTS AND METHODS

Sixty-nine patients with a median age of 42 (range: 18-67) and a median Karnofsky Performance Score of 90 (range: 70-100) were enrolled. Sixteen patients had a prior diagnosis of low-grade oligodendroglioma and 16 had mixed oligoastrocytoma pathology. Only patients with demonstrably chemosensitive enhancing tumors or those free of enhancing tumor after surgery and induction therapy were eligible to receive high-dose thiotepa.

RESULTS

Thirty-nine patients (57%) completed the transplant regimen; their estimated median progression-free survival is 69 months and median overall survival has not been reached. Twelve transplanted patients (31%) relapsed. Neither histology nor prior low-grade oligodendroglioma correlated with relapse; however, persistent non-enhancing tumor at transplant conferred an increased risk of relapse (p = 0.028). The transplant regimen was well-tolerated; median hospital stay was 20 days (range: 7-43) with a median time to ANC and platelet engraftment of 10 days. Thirty patients (43%) did not receive high-dose thiotepa because of stable or progressive disease (n = 21), excessive toxicity (n = 4), refusal of further therapy (n = 2), failure to obtain insurance coverage (n = 2), or other (n = 1). No treatment-related or long-term neurotoxicity was seen in the transplanted patients.

CONCLUSIONS

High-dose chemotherapy with stem cell rescue as initial treatment for anaplastic oligodendroglioma is feasible and associated with prolonged tumor control in some patients.