J. Gregory Cairncross

Effects of radiotherapy with concomitant and adjuvant temozolomide versus radiotherapy alone on survival in glioblastoma in a randomised phase III study: 5-year analysis of the EORTC-NCIC trial.

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, Nélia and Amadeo Barletta Foundation, Schering-Plough.

Nomograms for predicting survival of patients with newly diagnosed glioblastoma: prognostic factor analysis of EORTC and NCIC trial 26981-22981/CE.3

BACKGROUND A randomised trial published by the European Organisation for Research and Treatment of Cancer (EORTC) and the National Cancer Institute of Canada (NCIC) Clinical Trials Group (trial 26981-22981/CE.3) showed that addition of temozolomide to radiotherapy in the treatment of patients with newly diagnosed glioblastoma significantly improved survival. We aimed to undertake an exploratory subanalysis of the EORTC and NCIC data to confirm or identify new prognostic factors for survival in adult patients with glioblastoma, derive nomograms that predict an individual patients prognosis, and suggest stratification factors for future trials. METHODS Data from 573 patients with newly diagnosed glioblastoma who were randomly assigned to radiotherapy alone or to the same radiotherapy plus temozolomide in the EORTC and NCIC trial were included in this subanalysis. Survival modelling was done in three patient populations: intention-to-treat population of all randomised patients (population 1); patients assigned temozolomide and radiotherapy (population 2, n=287); and patients assigned temozolomide and radiotherapy who had assessment of MGMT promoter methylation status and who had undergone tumour resection (population 3, n=103). Cox proportional hazards models were fitted with and without O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. Nomograms were developed to predict an individual patients median and 2-year survival probabilities. No nomogram was developed in the radiotherapy-alone group because combined treatment is now the new standard of care. FINDINGS Independent of the MGMT promoter methylation status, analysis in all randomised patients (population 1) identified combined treatment with temozolomide, more extensive tumour resection, younger age, Mini-Mental State Examination (MMSE) score of 27 or higher, and no corticosteroid treatment at baseline as independent prognostic factors correlated with improved survival outcome. In patients assigned temozolomide and radiotherapy (population 2), younger age, better performance status, more extensive tumour resection, and MMSE score of 27 or higher were associated with better survival. In patients who had tumours resected, who were assigned temozolomide and radiotherapy, and who had available MGMT promoter methylation status (population 3), methylated MGMT, better performance status, and MMSE score of 27 or higher were associated with improved survival. Nomograms were developed and are available at http://www.eortc.be/tools/gbmcalculator. INTERPRETATION MGMT promoter methylation status, age, performance status, extent of resection, and MMSE are suggested as eligibility or stratification factors for future trials in patients with newly diagnosed glioblastoma. Stratifying by MGMT promoter methylation status should be mandatory in all glioblastoma trials that use alkylating chemotherapy. Nomograms can be used to predict an individual patients prognosis, and they integrate pertinent molecular information that is consistent with a paradigm shift towards individualised patient management.

A multigene predictor of outcome in glioblastoma

Only a subset of patients with newly diagnosed glioblastoma (GBM) exhibit a response to standard therapy. To date, a biomarker panel with predictive power to distinguish treatment sensitive from treatment refractory GBM tumors does not exist. An analysis was performed using GBM microarray data from 4 independent data sets. An examination of the genes consistently associated with patient outcome, revealed a consensus 38-gene survival set. Worse outcome was associated with increased expression of genes associated with mesenchymal differentiation and angiogenesis. Application to formalin fixed-paraffin embedded (FFPE) samples using real-time reverse-transcriptase polymerase chain reaction assays resulted in a 9-gene subset which appeared robust in these samples. This 9-gene set was then validated in an additional independent sample set. Multivariate analysis confirmed that the 9-gene set was an independent predictor of outcome after adjusting for clinical factors and methylation of the methyl-guanine methyltransferase promoter. The 9-gene profile was also positively associated with markers of glioma stem-like cells, including CD133 and nestin. In sum, a multigene predictor of outcome in glioblastoma was identified which appears applicable to routinely processed FFPE samples. The profile has potential clinical application both for optimization of therapy in GBM and for the identification of novel therapies targeting tumors refractory to standard therapy.

Glioma Classification: A Molecular Reappraisal

The modern clinical practice of neuro-oncology is dependent on accurate tumor classification. No variable predicts prognosis more precisely, and classification is also the basis on which clinicians make critical therapeutic recommendations to their individual patients: neuro-oncologists apply therapies in a relatively uniform way for all patients with a given tumor type. Hence, in a profound way, treatment of brain tumors is dictated by histological diagnosis. Furthermore, classification guides our scientific study of brain tumors, with biological understanding often based on a priori assumptions about specific tumor types. In the future, as specific therapies become based on individual biological alterations within tumors, precise classification will assume even greater importance to guide these distinct treatments. The primacy of accurate classification in neuro-oncology demands that critical attention be directed toward the problem, and encourages periodic re-evaluations of this essential issue. The present reappraisal is directed toward the diffuse gliomas. These are the most common of primary human brain tumors and comprise the bulk of adult neuro-oncology work. Diffuse gliomas are therapeutically vexing: their infiltrative (diffuse) growth pattern essentially prevents surgical cure, and the majority of these gliomas are resistant to standard chemotherapeutic and radiotherapeutic approaches. Nonetheless, some tumors are therapeutically sensitive and rare cures are effected. Paradoxically, these rare successes draw attention to the essential limitation of current glioma classification schemes: responding tumors may be histologically indistinguishable from nonresponding ones. Consequently, existing methods of glioma classification fall short of their ultimate goal of precisely guiding therapy. However, molecular biological studies of gliomas are making inroads toward an improved classification system for gliomas, one in which response to a specific therapy can be predicted for each individual patient. Furthermore, remarkable insights into the origins and behavior of gliomas are beginning to emerge from animal modeling of glial tumors and from basic research in developmental neurobiology. Together, such scientific advances and therapeutic successes provide an opportunity to question and perhaps refine the paradigm for classifying diffuse gliomas. The present reappraisal first defines the problems inherent in current glioma classification systems. Next, by reviewing advances in our molecular understanding of gliomas, we suggest that a more biological approach to glioma classification will provide improved means to type these tumors. Any new classification, however, must be based on clinical significance, and we thus point out the pressing need for better clinical endpoints and outcome measures in the field. Finally, by looking at basic advances in developmental neurobiology and animal modeling, we raise the possibility that we should begin to think of gliomas in a different conceptual framework. In combination, these data suggest that the present is an opportune time to begin to reconsider how glioma classification should advance during the next few years.

Supratentorial malignant glioma: Patterns of recurrence and implications for external beam local treatment

Pre- and postoperative computerized tomography scans, simulator films, and computerized tomography scans documenting tumor recurrence were analyzed on 70 patients with supratentorial malignant glioma treated with whole brain plus boost radiation therapy to determine sites of recurrence in relation to the boost. The boost was planned using the postoperative computerized tomography scan. Tumor recurred in 53 patients--within the boost in 38 (72%), partly outside the boost in 12 (23%), outside the boost but within the brain in one (2%), in the boost and in the spinal cord in one (2%), and in the spinal cord only in one (2%). All recurrences confined to the brain were found within 4 cm of the enhancing tumor as defined by the preoperative computerized tomography scan. Recurrences outside the boost were more common with inadequate boost margins, small boost volumes, temporal lobe tumors, and homolateral wedge pair technique. Survival was not adversely affected by recurrence outside the boost. We recommend that patients with malignant glioma be treated by parallel opposed fields with a margin that is 4 cm beyond the edge of the preoperative enhancing tumor, as seen on computerized tomography scan.

Concurrent CIC mutations, IDH mutations, and 1p/19q loss distinguish oligodendrogliomas from other cancers

Oligodendroglioma is characterized by unique clinical, pathological, and genetic features. Recurrent losses of chromosomes 1p and 19q are strongly associated with this brain cancer but knowledge of the identity and function of the genes affected by these alterations is limited. We performed exome sequencing on a discovery set of 16 oligodendrogliomas with 1p/19q co‐deletion to identify new molecular features at base‐pair resolution. As anticipated, there was a high rate of IDH mutations: all cases had mutations in either IDH1 (14/16) or IDH2 (2/16). In addition, we discovered somatic mutations and insertions/deletions in the CIC gene on chromosome 19q13.2 in 13/16 tumours. These discovery set mutations were validated by deep sequencing of 13 additional tumours, which revealed seven others with CIC mutations, thus bringing the overall mutation rate in oligodendrogliomas in this study to 20/29 (69%). In contrast, deep sequencing of astrocytomas and oligoastrocytomas without 1p/19q loss revealed that CIC alterations were otherwise rare (1/60; 2%). Of the 21 non‐synonymous somatic mutations in 20 CIC‐mutant oligodendrogliomas, nine were in exon 5 within an annotated DNA‐interacting domain and three were in exon 20 within an annotated protein‐interacting domain. The remaining nine were found in other exons and frequently included truncations. CIC mutations were highly associated with oligodendroglioma histology, 1p/19q co‐deletion, and IDH1/2 mutation (p < 0.001). Although we observed no differences in the clinical outcomes of CIC mutant versus wild‐type tumours, in a background of 1p/19q co‐deletion, hemizygous CIC mutations are likely important. We hypothesize that the mutant CIC on the single retained 19q allele is linked to the pathogenesis of oligodendrogliomas with IDH mutation. Our detailed study of genetic aberrations in oligodendroglioma suggests a functional interaction between CIC mutation, IDH1/2 mutation, and 1p/19q co‐deletion. Copyright

Pretreatment factors predict overall survival for patients with low-grade glioma : A recursive partitioning analysis

PURPOSE Three databases were pooled and analyzed to determine which groupings of prognostic factors best predicted overall survival for patients with low-grade gliomas treated with surgery and immediate or delayed radiotherapy. METHODS AND MATERIALS Databases of patients with low-grade gliomas compiled at the London Regional Cancer Centre (LRCC), the Norwegian Radium Hospital (NRH), and the University of California, San Francisco (UCSF) were merged. Inclusion criteria for the pooled analysis included: age > or =18 years and histologically confirmed low-grade (World Health Organization Grade II) supratentorial fibrillary astrocytoma, oligodendroglioma or mixed oligoastrocytoma. Factors analyzed for prognostic significance included: age at diagnosis, gender, seizures at presentation, presence of enhancement on computed tomography (CT) or magnetic resonance imaging (MRI), Karnofsky Performance Status (KPS) at diagnosis, histology, extent of surgical resection, timing of radiotherapy, and treating institution. Univariate and multivariate analysis of overall survival for these factors was performed. Recursive partitioning was performed to generate prognostic groups using these factors. RESULTS From the combined databases, 401 patients were eligible for analysis. Median survival for the entire group was 95 months/7.9 years. On univariate analysis age 18-40, presence of seizures at presentation, KPS > or =70, treating institution, and absence of contrast enhancement were associated with improved overall survival. On multivariate analysis, these factors remained independent predictors of improved overall survival. Recursive partitioning analysis yielded four prognostic groups with statistically different median survivals (MS): Group I (n = 41: KPS <70, age >40) MS 12 months; Group II (n = 34: KPS > or =70, age >40, enhancement present) MS 46 months; Group III (n = 138: KPS <70, age 18-40 or KPS > or =70 age >40, no enhancement) MS 87 months; Group IV (n = 188: KPS > or =70, age 18-40) MS 128 months. CONCLUSION Clusters of pretreatment prognostic factors described subgroups of low-grade glioma patients with divergent overall survivals. Consideration of these prognostic subgroups may be important when considering timing of interventions for these patients and in the stratification of patients for clinical trials.

Benefit From Procarbazine, Lomustine, and Vincristine in Oligodendroglial Tumors Is Associated With Mutation of IDH

PURPOSE Patients with 1p/19q codeleted anaplastic oligodendroglial tumors who participated in RTOG (Radiation Therapy Oncology Group) 9402 lived much longer after chemoradiotherapy (CRT) than radiation therapy (RT) alone. However, some patients with noncodeleted tumors also benefited from CRT; survival curves separated after the median had been reached, and significantly more patients lived ≥ 10 years after CRT than RT. Thus, 1p/19q status may not identify all responders to CRT. PATIENTS AND METHODS Using trial data, we inquired whether an IDH mutation or germ-line polymorphism associated with IDH-mutant gliomas identified the patients in RTOG 9402 who benefited from CRT. RESULTS IDH status was evaluable in 210 of 291 patients; 156 (74%) had mutations. rs55705857 was evaluable in 245 patients; 76 (31%) carried the G risk allele. Both were associated with longer progression-free survival after CRT, and mutant IDH was associated with longer overall survival (9.4 v 5.7 years; hazard ratio [HR], 0.59; 95% CI, 0.40 to 0.86; P = .006). For those with wild-type tumors, CRT did not prolong median survival (1.3 v 1.8 years; HR, 1.14; 95% CI, 0.63 to 2.04; P = .67) or 10-year survival rate (CRT, 6% v RT, 4%). Patients with codeleted mutated tumors (14.7 v 6.8 years; HR, 0.49; 95% CI, 0.28 to 0.85; P = .01) and noncodeleted mutated tumors (5.5 v 3.3 years; HR, 0.56; 95% CI, 0.32 to 0.99; P < .05) lived longer after CRT than RT. CONCLUSION IDH mutational status identified patients with oligodendroglial tumors who did (and did not) benefit from alkylating-agent chemotherapy with RT. Although patients with codeleted tumors lived longest, patients with noncodeleted IDH-mutated tumors also lived longer after CRT.

PTEN is a target of chromosome 10q loss in anaplastic oligodendrogliomas and PTEN alterations are associated with poor prognosis.

Allelic loss of 10q is a common genetic event in malignant gliomas, with three 10q tumor suppressor genes, ERCC6, PTEN, and DMBT1, putatively implicated in the most common type of malignant glioma, glioblastoma. Anaplastic oligodendroglioma, another type of malignant glioma, provides a unique opportunity to study the relevance of particular genetic alterations to chemosensitivity and survival. We therefore analyzed these three genes in 72 anaplastic oligodendrogliomas. Deletion mapping demonstrated 10q loss in 14 of 67 informative cases, with the PTEN and DMBT1 regions involved in all deletions but with the ERCC6 locus spared in two cases. Seven tumors had PTEN gene alterations; two had homozygous DMBT1 deletions, but at least one reflected unmasking of a germline DMBT1 deletion. No mutations were found in ERCC6 exon 2. Chemotherapeutic response occurred in two of the seven tumors with PTEN alterations, but with unexpected short survival times. PTEN gene alterations were not associated with poor therapeutic response in multivariate analysis, but were independently predictive of poor prognosis even after multivariate adjustment for both 10q and 1p loss. In anaplastic oligodendroglioma, therefore, PTEN is a target of 10q loss, and PTEN alterations are associated with poor prognosis, even in chemosensitive cases.

A prospective study of short-course radiotherapy in poor prognosis glioblastoma multiforme

PURPOSE Older age and poor performance status at presentation are unfavorable prognostic factors for patients with glioblastoma multiforme. Some studies suggest a shorter, palliative course of radiotherapy may confer similar benefits as compared to a radical course in such patients. We report a prospective, single arm trial, describing the use of a short-course of radiation in patients with glioblastoma and poor prognostic features. METHODS AND MATERIALS Twenty-nine patients with pathologically confirmed glioblastoma and age > or = 65 years or with initial KPS < or = 50 were treated with a short-course of whole brain radiotherapy (30 Gy/10 fractions/2 weeks). Computer tomography tumor volume, dexamethasone requirements, Spitzer quality of life index, and Karnofsky performance status were measured pre and 1 month postradiation. Overall survival for the study patients was compared with that of radically treated and supportive care only historical controls. RESULTS Indices of tumor response were stable or improved in 60% of patients evaluable 1 month postradiotherapy. Median survival for all study patients was 6 months. Median survivals in similar groups of radically treated and supportive care only patients were 10 and 1 month(s), respectively. A survival advantage for the radical vs. short-course treatment was observed for the subset of patients with a pretreatment KPS > 50. CONCLUSION Elderly patients with a low pretreatment KPS (< or = 50) may be treated adequately with a short, palliative course of radiotherapy. Elderly patients with a higher pretreatment KPS (> 50), however, may benefit from a higher dose radiotherapy regimen.