Treatment of glioblastoma multiforme with radiotherapy and concomitant and adjuvant temozolomide: translation of randomised controlled trial evidence into routine clinical practice

Normalized Apparent Diffusion Coefficient in the Prognostication of Patients with Glioblastoma Multiforme

BACKGROUND

Glioblastoma multiforme (GBM) is known to have poor prognosis, with no available imaging marker that can predict survival at the time of diagnosis. Diffusion weighted images are used in characterisation of cellularity and necrosis of GBM. The purpose of this study was to assess whether pattern or degree of diffusion restriction could help in the prognostication of patients with GBM.

MATERIAL AND METHODS

We retrospectively analyzed 84 consecutive patients with confirmed GBM on biopsy or resection. The study was approved by the institutional ethics committee. The total volume of the tumor and total volume of tumor showing restricted diffusion were calculated. The lowest Apparent Diffusion Coefficient (ADC) in the region of the tumor and in the contralateral Normal Appearing White Matter were calculated in order to calculate the nADC. Treatment and follow-up data in these patients were recorded. Multivariate analsysis was completed to determine significant correlations between different variables and the survival of these patients.

RESULTS

Patient survival was significantly related to the age of the patient (p<0.0001; 95% CI-1.022-1.043) and the nADC value (p=0.014; 95% CI-0.269-0.860) in the tumor. The correlation coefficients of age and nADC with survival were -0.335 (p=0.002) and 0.390 (p<0.001), respectively. Kaplan Meier survival function, grouped by normalized Apparent Diffusion Coefficient cut off value of 0.75, was significant (p=0.007).

CONCLUSION

The survival of patients with GBM had small, but significant, correlations with the patient's age and nADC within the tumor.

Pharmacologic therapies for malignant glioma: a guide for clinicians

This review covers the medical options for malignant gliomas based on the results of recent clinical trials and updated information on molecular markers of prognostic and predictive value. In addition to alkylating agents, the antiangiogenic drug bevacizumab is increasingly used, particularly in cases of recurrence. Supportive care, including antiedema agents, antiepileptic drugs and anticoagulants, represent complementary treatment approaches of the utmost clinical importance.

Change in platelet levels during radiotherapy with concurrent and adjuvant temozolomide for the treatment of glioblastoma: a novel prognostic factor for survival

BACKGROUND

Radiotherapy plus concomitant and adjuvant temozolomide (RCAT) is now standard treatment for grade IV glioblastoma (GBM). We report the results from our 7 years experience of using RCAT, and the potential role of a change in platelet count as a prognostic factor.

METHODS

We identified all patients with biopsy-proven GBM who received RCAT at the Royal Free Hospital between 2002 and 2009. We extracted data on demographic, tumour and treatment variables and overall survival and conducted univariate analyses on the association of the baseline factors with survival, and included those that were significant in a multivariate model. We then conducted exploratory analyses on the impact of changes in haematological parameters and overall survival.

RESULTS

A total of eighty-four patients were included in the final analysis. Median overall survival in our study was 17.6 months. Overall survival rate at 1 year and 2 years were 70 and 36 %, respectively. Platelet counts were seen to fall when measured from baseline to beginning of week 6. A decrease in platelet count from baseline to week 6 was associated with longer survival (p = 0.006), and this remains significant when adjusted for known prognostic factors.

CONCLUSION

Our study shows the survival benefit seen in the phase III trial is reproducible in clinical practice. In addition, decreased platelet count during concurrent radiotherapy and temozolomide appears to correlate with prolonged survival, a finding that warrants further investigation.

Apparent diffusion coefficient histogram analysis stratifies progression-free and overall survival in patients with recurrent GBM treated with bevacizumab: a multi-center study

We have tested the predictive value of apparent diffusion coefficient (ADC) histogram analysis in stratifying progression-free survival (PFS) and overall survival (OS) in bevacizumab-treated patients with recurrent glioblastoma multiforme (GBM) from the multi-center BRAIN study. Available MRI's from patients enrolled in the BRAIN study (n = 97) were examined by generating ADC histograms from areas of enhancing tumor on T1 weighted post-contrast images fitted to a two normal distribution mixture curve. ADC classifiers including the mean ADC from the lower curve (ADC-L) and the mean lower curve proportion (LCP) were tested for their ability to stratify PFS and OS by using Cox proportional hazard ratios and the Kaplan-Meier method with log-rank test. Mean ADC-L was 1,209 × 10(-6)mm(2)/s ± 224 (SD), and mean LCP was 0.71 ± 0.23 (SD). Low ADC-L was associated with worse outcome. The hazard ratios for 6-month PFS, overall PFS, and OS in patients with less versus greater than mean ADC-L were 3.1 (95 % confidence interval: 1.6, 6.1; P = 0.001), 2.3 (95 % CI: 1.3, 4.0; P = 0.002), and 2.4 (95 % CI: 1.4, 4.2; P = 0.002), respectively. In patients with ADC-L <1,209 and LCP >0.71 versus ADC-L >1,209 and LCP <0.71, there was a 2.28-fold reduction in the median time to progression, and a 1.42-fold decrease in the median OS. The predictive value of ADC histogram analysis, in which low ADC-L was associated with poor outcome, was confirmed in bevacizumab-treated patients with recurrent GBM in a post hoc analysis from the multi-center (BRAIN) study.

Temozolomide plus radiotherapy for glioblastoma in a Canadian province: Efficacy versus effectiveness and the impact of O6-methylguanine-DNA-methyltransferase promoter methylation

Background: Radiotherapy with concomitant and adjuvant temozolomide has been the standard of care for newly diagnosed glioblastoma in adults since the pivotal trial by Roger Stupp and colleagues. The effectiveness of this regimen has not been evaluated in Canada. Additionally, the impact of O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation on patient survival has not been confirmed. Hence, survival outcomes and MGMT predictive value were compared for the patients in Alberta versus the Stupp trial population.

Methods: Retrospective chart review of 215 adult glioblastoma patients who started radiotherapy and temozolomide between January 2007 and December 2010 at the Cross Cancer Institute (Edmonton, Alberta) or the Tom Baker Cancer Centre (Calgary, Alberta).

Results: In the Alberta population, median overall survival was 14.3 months (vs. 14.6 months in trial, p = NS) and median progression-free survival was 5.8 months (vs. 6.9 months in trial, p = NS). However, unlike the trial, the Alberta MGMT subgroup analysis for overall survival was not statistically significant, despite a hazard ratio of 0.65 in favor of the methylated group. More Alberta patients received corticosteroids ( p < 0.0001) and fewer underwent complete resection ( p = 0.0001) or a postprogression second surgery ( p = 0.01) than the Stupp population, but characteristics were otherwise similar.

Conclusion: Current practice in Alberta enables patients to achieve overall and progression-free survival similar to the clinical trial. Further follow-up is required to confirm the predictive value of the MGMT assay. Until that is clarified or better treatments are developed, it is reasonable to continue offering this treatment regimen to patients regardless of MGMT methylation status.