OS07.5.A Report from the pooled analysis of the randomized trials NORDIC, NOA-8 and CE.6 on elderly patients with glioblastoma

Background

The majority of patients diagnosed with glioblastoma are over 60 years old. Three randomized trials addressed the roles of radiotherapy (RT) and temozolomide (TMZ) for these patients. Two, the NORDIC and NOA-08 (N&N) compared RT versus TMZ head-to-head, the third, CE.6, randomized between hypofractionated RT and the combination of RT+TMZ. All showed significant benefit for the TMZ arms, especially for patients with MGMT promoter methylated tumors. An ongoing pooled analysis of these three trials focuses on identifying significant baseline prognostic factors and assess their value for predicting outcome in relation to treatment. The aim is improved selection of elderly patients with glioblastoma for their optimal treament; RT alone, TMZ with or without concomitant RT or palliative care.

Methods

The data of two phase 3 studies (N&N) were pooled to build a large dataset and findings are compared to CE.6 trial data. A re-assessment of the clinically most relevant MGMT cut-off is performed. The prognostic value of baseline clinical factors and quality of life scores, determined by the EORTC QLQ-30 and BN-20 questionnaires, are investigated. Data is also analysed to account for a possible impact of sex.

Results

The N&N dataset includes 715 and the comparative dataset (CE.6) 562 patients. Median age for N&N is 71 years and 73 for CE.6. In N&N and CE.6 respectively, 66.2% versus 70.5% underwent resection and 50.9% and 75.3% were on steroids at the time of study inclusion. In N&N, 401 patients received RT alone and 281 in CE.6, while 314 were randomized to TMZ alone in N&N and 281 to concomitant RT and TMZ in CE.6. For N&N MGMT promoter methylation status was successfully determined for 412 (57.6%) and 354 (63.0%) for CE.6. In a first report, patients with the combination of the comorbidities hypertension, diabetes and/or cerebrovascular insult had poorer prognosis when treated with TMZ.

Conclusion

An ongoing pooled analysis of the trials NORDIC, NOA-08 and CE.6 is expected to identify factors that will improve personalized medicine for elderly patients with glioblastoma. Reanalyzed MGMT promoter methylation data and the role of baseline quality of life for outcome will be reported.

BRAF V600E mutant oligodendroglioma-like tumors with chromosomal instability in adolescents and young adults

We performed genome-wide methylation analysis on 136 pediatric low-grade gliomas, identifying a unique cluster consisting of three tumors with oligodendroglioma-like histology, BRAF p.V600E mutations and recurrent whole chromosome gains of 7 and loss of 10. Morphologically, all showed similar features, including a diffusely infiltrative glioma composed of round nuclei with perinuclear halos, a chicken-wire pattern of branching capillaries and microcalcification. None showed astrocytic features or characteristics suggestive of high-grade tumors including necrosis or mitotic figures. All tumors harbored multiple chromosomal copy number abnormalities (>10 chromosomes altered), but none showed 1p/19q co-deletion or IDH1 p.R132H mutation. Hierarchical clustering and t-stochastic neighbor embedding analyses from DNA methylation data cluster them more closely to previously described pediatric-type low-grade gliomas and separate from adult gliomas. These tumors exhibit distinct clinical features; they are temporal lobe lesions occurring in adolescents and young adults with a prolonged history of seizures and all are alive with no recurrence (follow-up 3.2 to 13.2 years). We encountered another young adult case with quite similar pathological appearance and molecular status except for TERT promoter mutation. Although the series is small, these may represent a new category of IDH wild-type low-grade gliomas which may be confused with "molecular GBM." Further, they highlight the heterogeneity of IDH wild-type gliomas and the relatively indolent behavior of "pediatric-type" gliomas.

The Brain Metastases Symptom Checklist as a novel tool for symptom measurement in patients with brain metastases undergoing whole-brain radiotherapy

PURPOSE

We evaluated the feasibility, reliability, and validity of the Brain Metastases Symptom Checklist (bmsc), a novel self-report measure of common symptoms experienced by patients with brain metastases.

METHODS

Patients with first-presentation symptomatic brain metastases (n = 137) referred for whole-brain radiotherapy (wbrt) completed the bmsc at time points before and after treatment. Their caregivers (n = 48) provided proxy ratings twice on the day of consultation to assess reliability, and at week 4 after wbrt to assess responsiveness to change. Correlations with 4 other validated assessment tools were evaluated.

RESULTS

The symptoms reported on the bmsc were largely mild to moderate, with tiredness (71%) and difficulties with balance (61%) reported most commonly at baseline. Test-retest reliability for individual symptoms had a median intraclass correlation of 0.59 (range: 0.23-0.85). Caregiver proxy and patient responses had a median intraclass correlation of 0.52. Correlation of absolute scores on the bmsc and other symptom assessment tools was low, but consistency in the direction of symptom change was observed. At week 4, change in symptoms was variable, with improvements in weight gain and sleep of 42% and 41% respectively, and worsening of tiredness and drowsiness of 62% and 59% respectively.

CONCLUSIONS

The bmsc captures a wide range of symptoms experienced by patients with brain metastases, and it is sensitive to change. It demonstrated adequate test-retest reliability and face validity in terms of its responsiveness to change. Future research is needed to determine whether modifications to the bmsc itself or correlation with more symptom-specific measures will enhance validity.

Factors influencing overall survival specific to adult low-grade astrocytoma: a population-based study

AIMS

We report a population-based overall survival and prognostic factor analysis specific to adult patients diagnosed with low-grade astrocytoma (LGA).

MATERIALS AND METHODS

All histologically confirmed cases of LGA diagnosed between 1992 and 1996 in the province of Ontario, Canada, were identified from the Ontario Cancer Registry and reviewed.

RESULTS

In total, 182 patients were identified; the mean age was 50 years and the mean survival time was 4.1 years (standard deviation = 5.1 years). Fifty-four per cent of patients had a surgical excision and 46% were biopsied alone. Both univariate and multivariate analyses showed that patients aged <30 years were significantly more likely to undergo an excision as compared with a biopsy alone (odds ratio = 4.26, 95% confidence interval 1.54-11.77). For the entire cohort, we observed a significant relationship between decreasing survival as a function of increasing age at diagnosis. In the biopsy sub-group, relative to patient's age <30 years, the hazard of dying increased significantly according to age when stratified by decade. However, in those patients having had a primary surgical excision, the hazard of dying relative to patient's age <30 years was similar for those aged 30-49 years and then significantly greater as patient age surpassed 50 years.

CONCLUSIONS

Age is a significant prognostic factor for LGA. Our analysis suggests that in those patients amenable to a primary tumour excision, a survival benefit may be confined to those under age 50 years.

Stereotactic radiosurgery for the treatment of melanoma and renal cell carcinoma brain metastases

Renal cell carcinoma (RCC) and melanoma brain metastases have traditionally been considered radioresistant lesions when treated with conventional radiotherapeutic modalities. Radiosurgery provides high-dose radiation to a defined target volume with steep fall off in dose at lesion margins. Recent evidence suggests that stereotactic radiosurgery (SRS) is effective in improving local control and overall survival for a number of tumor subtypes including RCC and melanoma brain metastases. The purpose of this study was to compare the response rate to SRS between RCC and melanoma patients and to identify predictors of response to SRS for these 2 specific subtypes of brain metastases. We retrospectively reviewed a prospectively maintained database of all brain metastases treated with Gamma Knife SRS at the University Health Network (Toronto, Ontario) between October 2007 and June 2010, studying RCC and melanoma patients. Demographics, treatment history and dosimetry data were collected; and MRIs were reviewed for treatment response. Log rank, Cox proportional hazard ratio and Kaplan-Meier survival analysis using SPSS were performed. A total of 103 brain metastases patients (41 RCC; 62 melanoma) were included in the study. The median age, Karnofsky performance status score and Eastern Cooperative Oncology Group performance score was 52 years (range 27-81), 90 (range 70-100) and 1 (range 0-2), respectively. Thirty-four lesions received adjuvant chemotherapy and 56 received pre-SRS whole brain radiation therapy. The median follow-up, prescription dose, Radiation Therapy Oncology Group conformity index, target volume and number of shots was 6 months (range 1-41 months), 21 Gy (range 15-25 Gy), 1.93 (range 1.04-9.76), 0.4 cm3 (range 0.005-13.36 cm3) and 2 (range 1-22), respectively. Smaller tumor volume (P=0.007) and RCC pathology (P=0.04) were found to be positive predictors of response. Actuarial local control rate for RCC and melanoma combined was 89% at 6 months, 84% at 12 months, 76% at 18 months and 61% at 24 months. Local control at 12 months was 91 and 75% for RCC and melanoma, respectively. SRS is a valuable treatment option for local control of RCC and melanoma brain metastases. Smaller tumor volume and RCC pathology, predictors of response, suggest distinct differences in tumor biology and the extent of radioresponse between RCC and melanoma.

Clinical outcomes of adult patients with primary intracranial germinomas treated with low-dose craniospinal radiotherapy and local boost

The authors document the long term follow up of adult patients with histologically proven primary intracranial germinoma treated with radiotherapy alone using a craniospinal with local boost technique. A retrospective review was conducted on adults diagnosed with intracranial germinoma who received radiotherapy at the Princess Margaret Hospital, Toronto from 1990 to 2007. The study group consisted of 10 males with a median age of 24.1 years. All patients received radiotherapy alone using craniospinal radiotherapy and local boost. There were 10 patients (all male) with a median follow up of 10.9 years (range 2.2-18.9 years). At date of last follow up all patients were still alive, none with relapsed disease. Seven of ten patients (70%) had panhypopituitarianism prior to commencing radiotherapy and hormonal function was not affected in those with an intact pituitary axis. There was no reported cognitive decline in the treated cohort. For adult intracranial germinomas, with long term follow up, low-dose craniospinal radiotherapy with in field boost is highly effective with minimal morbidity.

Management of single brain metastasis: a practice guideline

QUESTIONS

Should patients with confirmed single brain metastasis undergo surgical resection? Should patients with single brain metastasis undergoing surgical resection receive adjuvant whole-brain radiation therapy (wbrt)? What is the role of stereotactic radiosurgery (srs) in the management of patients with single brain metastasis?

PERSPECTIVES

Approximately 15%-30% of patients with cancer will develop cerebral metastases over the course of their disease. Patients identified as having single brain metastasis generally undergo more aggressive treatment than do those with multiple metastases; however, in the province of Ontario, management of patients with single brain metastasis varies. Given that conflicting evidence has been reported, the Neuro-oncology Disease Site Group (dsg) of the Cancer Care Ontario Program in Evidence-based Care felt that a systematic review of the evidence and a practice guideline were warranted.

OUTCOMES

Outcomes of interest were survival, local control of disease, quality of life, and adverse effects.

METHODOLOGY

The medline, cancerlit, embase, and Cochrane Library databases and abstracts published in the proceedings of the annual meetings of the American Society of Clinical Oncology (1997-2005) and American Society for Therapeutic Radiology and Oncology (1998-2004) were systematically searched for relevant evidence. The review included fully published reports or abstracts of randomized controlled trials (rcts), nonrandomized prospective studies, and retrospective studies. The present systematic review and practice guideline has been reviewed and approved by the Neuro-oncology dsg, which comprises medical and radiation oncologists, surgeons, neurologists, a nurse, and a patient representative. External review by Ontario practitioners was obtained through an electronic survey. Final approval of the guideline report was obtained from the Report Approval Panel and the Neuro-oncology dsg.

RESULTS

QUALITY OF EVIDENCE

The literature search found three rcts that compared surgical resection plus wbrt with wbrt alone. In addition, a Cochrane review, including a meta-analysis of published data from those three rcts, was obtained. One rct compared surgical resection plus wbrt with surgical resection alone. One rct compared wbrt plus srs with wbrt alone. Evidence comparing srs with surgical resection or examining srs with or without wbrt was limited to prospective case series and retrospective studies.

BENEFITS

Two of three rcts reported a significant survival benefit for patients who underwent surgical resection as compared with those who received wbrt alone. Pooled results of the three rcts indicated no significant difference in survival or likelihood of dying from neurologic causes; however, significant heterogeneity was detected between the trials. The rct that compared surgical resection plus wbrt with surgical resection alone reported no significant difference in overall survival or length of functional independence; however, tumour recurrence at the site of the metastasis and anywhere in the brain was less frequent in patients who received wbrt as compared with patients in the observation group. In addition, patients who received wbrt were less likely to die from neurologic causes. Results of the rct that compared wbrt plus srs with wbrt alone indicated a significant improvement in median survival in patients who received srs. No quality evidence compares the efficacy of srs with surgical resection or examines the question of whether patients who receive srs should also receive wbrt.

HARMS

Pooled results of the three rcts that examined surgical resection indicated no significant difference in adverse effects between groups. Postoperative complications included respiratory problems, intracerebral hemorrhage, and infection. One rct reported no significant difference in adverse effects between patients who received wbrt plus srs and those who received wbrt alone.

PRACTICE GUIDELINE

TARGET POPULATION

The recommendations that follow apply to adults with confirmed cancer and a single brain metastasis. This practice guideline does not apply to patients with metastatic lymphoma, small-cell lung cancer, germ-cell tumour, leukemia, or sarcoma.

RECOMMENDATIONS

Surgical excision should be considered for patients with good performance status, minimal or no evidence of extracranial disease, and a surgically accessible single brain metastasis amenable to complete excision. Because treatment in cases of single brain metastasis is considered palliative, invasive local treatments must be individualized. Patients with lesions requiring emergency decompression because of intracranial hypertension were excluded from the rcts, but should be considered candidates for surgery. To reduce the risk of tumour recurrence for patients who have undergone resection of a single brain metastasis, postoperative wbrt should be considered. The optimal dose and fractionation schedule for wbrt is 3000 cGy in 10 fractions or 2000 cGy in 5 fractions. As an alternative to surgical resection, wbrt followed by srs boost should be considered for patients with single brain metastasis. The evidence is insufficient to recommend srs alone as a single-modality therapy.

QUALIFYING STATEMENTS

No high-quality data are available regarding the choice of surgery versus radiosurgery for single brain metastasis. In general, the size and location of the metastasis determine the optimal approach. The standard wbrt regimen for management of patients with single brain metastasis in the United States is 3000 cGy in 10 fractions, and this treatment is usually the standard arm in randomized studies of radiation in patients with brain metastases. Based solely on evidence, the understanding that no reason exists to choose 3000 cGy in 10 fractions over 2000 cGy in 5 fractions is correct; however, fraction size is believed to be important, and therefore 300 cGy daily (3000/10) is believed to be associated with fewer long-term neurocognitive effects than 400 cGy daily (2000/5) in the occasional long-term survivor. For that reason, many radiation oncologists in Ontario prefer 3000 cGy in 10 fractions. No data exist to either support or refute that preference; therefore, finding a resolution to this issue is not currently possible. The Neuro-oncology dsg will update the recommendations as new evidence becomes available.