Discontinuing bevacizumab in patients with glioblastoma: an ethical analysis

Hypofractionated radiation therapy versus chemotherapy with temozolomide in patients affected by RPA class V and VI glioblastoma: a randomized phase II trial

INTRODUCTION

In RPA V-VI glioblastoma patients both hypofractionated radiotherapy and exclusive temozolomide can be used; the purpose of this trial is to compare these treatment regimens in terms of survival and quality of life.

METHODS

Patients with histologic diagnosis of glioblastoma were randomized to hypofractionated radiotherapy (RT-30 Gy in 6 fractions) and exclusive chemotherapy (CHT-emozolomide 200 mg/m²/day 5 days every 28 days). Overall (OS) and progression free survival (PFS) were evaluated with Kaplan Maier curves and correlated with prognostic factors. Quality- adjusted survival (QaS) was evaluated according to the Murray model (Neurological Sign and Symptoms-NSS) RESULTS: From 2010 to 2015, 31 pts were enrolled (CHT: 17 pts; RT: 14pts). Four pts were excluded from the analysis. RPA VI (p = 0.048) and absence of MGMT methylation (p = 0.001) worsened OS significantly. Biopsy (p = 0.048), RPA class VI (p = 0.04) and chemotherapy (p = 0.007) worsened PFS. In the two arms the initial NSS scores were overlapping (CHT: 12.23 and RT: 12.30) and progressively decreased in both group and became significantly worse after 5 months in CHT arm (p = 0.05). Median QaS was 104 days and was significantly better in RT arm (p = 0.01).

CONCLUSIONS

The data obtained are limited by the poor accrual. Both treatments were well tolerated. Patients in RT arm have a better PFS and QaS, without significant differences in OS. The deterioration of the NSS score would seem an important parameter and coincide with disease progression rather than with the toxicity of the treatment.

Post-bevacizumab Clinical Outcomes and the Impact of Early Discontinuation of Bevacizumab in Patients with Recurrent Malignant Glioma

Purpose

Bevacizumab±irinotecan is effective for treatment of recurrent malignant gliomas. However, the optimal duration of treatment has not been established.

Materials and Methods

Ninety-four consecutive patients with recurrent malignant glioma who were treated with bevacizumab at our institutions were identified. Patients who continued bevacizumab until tumor progression were enrolled in a late discontinuation (LD) group, while those who stopped bevacizumab before tumor progression were enrolled in an early discontinuation (ED) group. Landmark analyses were performed at weeks 9, 18, and 26 for comparison of patient survival between the two groups.

Results

Among 89 assessable patients, 62 (69.7%) and 27 (30.3%) patients were categorized as the LD and ED groups, respectively. According to landmark analysis, survival times from weeks 9, 18, and 26 were not significantly different between the two groups in the overall population. However, the LD group showed a trend toward increased survival compared to the ED group among responders. In the ED group, the median time from discontinuation to disease progression was 11.4 weeks, and none of the patients showed a definite rebound phenomenon. Similar median survival times after disease progression were observed between groups (14.4 weeks vs. 15.7 weeks, p=0.251). Of 83 patients, 38 (45.8%) received further therapy at progression, and those who received further therapy showed longer survival in both the LD and ED groups.

Conclusion

In recurrent malignant glioma, duration of bevacizumab was not associated with survival time in the overall population. However, ED of bevacizumab in responding patients might be associated with decreased survival.

Perspectives of Medical Specialists on Sharing Decisions in Cancer Care: A Qualitative Study Concerning Chemotherapy Decisions With Patients With Recurrent Glioblastoma

BACKGROUND

In cancer care, difficult decisions concerning advanced treatment need to be made, weighing possible life prolongation against harmful side effects. Treatment is frequently started, showing the need to explore how decisions are made. Little is known about the perspectives of physicians on sharing decision making with patients. This qualitative study aimed to describe the perspectives of medical specialists on the decision-making process with patients with glioblastoma concerning starting new treatment.

METHODS

Qualitative interviews were held with medical specialists. One focus group was organized with medical professionals. Their opinions about elements of shared decision making and the applicability in the context of patients with glioblastoma were assessed. The topic list for the focus group was based on the analysis of the interviews. Qualitative analysis of the transcripts was performed by three researchers independently.

RESULTS

Medical specialists considered shared decision making to be important; however, they did not adhere to its elements. Stopping treatment was not considered equal to continuing treatment. Exploration of the patients' wishes was done implicitly, and shared responsibility for the decision was not highly recognized. The main barriers to shared decision making were preferences of both patients and specialists for starting or continuing treatment and assumptions of physicians about knowing what patients want.

CONCLUSION

Medical specialists recognized the importance of patient involvement but experienced difficulty in sharing decision making in practice. Elements of shared decision making are partly followed but do not guide decision making. To improve cancer care, education of medical specialists and adjustment to the elements are needed to involve patients.

Bevacizumab in recurrent glioblastoma: five informative patient scenarios

Glioblastoma is the most common and malignant primary brain tumour in adults. Maximum feasible surgical resection, radiotherapy and temozolomide chemotherapy at initial diagnosis have improved prognosis but rapid recurrence is typical and survival remains brief. There is an urgent need for effective new treatments and approval of the antiangiogenic agent bevacizumab for recurrent glioblastoma by Health Canada in 2009 has been the most notable recent therapeutic advance for this disease. This review with illustrative case studies highlights how bevacizumab has been incorporated into the treatment of glioblastoma in Canada and describes the ongoing controversies surrounding its clinical application.

Bevacizumab for glioblastoma-a promising drug or not?

Two double blind, placebo-controlled, and randomized phase III studies were conducted, and the results including OS’s were reported at the ASCO Meeting in June 2013, which was the beginning of confusion surrounding this topic. This is a review article not only summarizing the previous evidence, but also looking beyond.

Phase II trial of continuous low-dose temozolomide for patients with recurrent malignant glioma

BACKGROUND

In this phase II trial, we investigated the efficacy of a metronomic temozolomide schedule in the treatment of recurrent malignant gliomas (MGs).

METHODS

Eligible patients received daily temozolomide (50 mg/m2) continuously until progression. The primary endpoint was progression-free survival rate at 6 months in the glioblastoma cohort (N = 37). In an exploratory analysis, 10 additional recurrent grade III MG patients were enrolled. Correlative studies included evaluation of 76 frequent mutations in glioblastoma (iPLEX assay, Sequenom) aiming at establishing the frequency of potentially "drugable" mutations in patients entering recurrent MG clinical trials.

RESULTS

Among glioblastoma patients, median age was 56 y; median Karnofsky performance score (KPS) was 80; 62% of patients had been treated for ≥2 recurrences, including 49% of patients having failed bevacizumab. Treatment was well tolerated; clinical benefit (complete response + partial response + stable disease) was seen in 10 (36%) patients. Progression-free survival rate at 6 months was 19% and median overall survival was 7 months. Patients with previous bevacizumab exposure survived significantly less than bevacizumab-naive patients (median overall survival: 4.3 mo vs 13 mo; hazard ratio = 3.2; P = .001), but those patients had lower KPS (P = .04) and higher number of recurrences (P < .0001). Mutations were found in 13 of the 38 MGs tested, including mutations of EGFR (N = 10), IDH1 (N = 5), and ERBB2 (N = 1).

CONCLUSIONS

In spite of a heavily pretreated population, including nearly half of patients having failed bevacizumab, the primary endpoint was met, suggesting that this regimen deserves further investigation. Results in bevacizumab-naive patients seemed particularly favorable, while results in bevacizumab-failing patients highlight the need to develop further treatment strategies for advanced MG. Clinical trials.gov identifier NCT00498927 (available at http://clinicaltrials.gov/ct2/show/NCT00498927).

Response assessment in recurrent glioblastoma treated with irinotecan-bevacizumab: comparative analysis of the Macdonald, RECIST, RANO, and RECIST + F criteria

Traditionally, the most widely used criteria for response assessment in glioblastoma have been Macdonald and the Response Evaluation Criteria In Solid Tumors (RECIST). Recently, new criteria addressing contrast enhancement and fluid-attenuated inversion recovery (FLAIR)/T2 hyperintensity have been defined (the Response Assessment in Neuro-Oncology criteria) to better evaluate the effect of antiangiogenic therapy. Whether FLAIR/T2 imaging could also be helpful to refine RECIST criteria remains unresolved. This study proposed the RECIST + F criteria and compared the 4 methods (Macdonald, RECIST, RANO, and RECIST + F) to determine their agreement in identifying response and progression of recurrent glioblastomas to irinotecan-bevacizumab. Patients with recurrent glioblastoma treated with second-line irinotecan-bevacizumab were eligible. Clinical status, corticosteroid dose, and 1-dimensional and 2-dimensional measurements of tumor contrast enhancement and FLAIR hyperintensity were retrospectively assessed. Response and progression were determined according to each set of criteria. Seventy-eight patients were included. Response rates ranged from 34.2% with RECIST + F to 44.7% with Macdonald criteria. Agreement among the 4 methods in determining response and type of progression was high (kappa statistic > 0.75). One-third of patients exhibited nonenhancing progression with stable or improved contrast enhancement. Median progression-free survival was predicted by RECIST, at 13.6 weeks; RECIST + F, 12.3; Macdonald, 12.7; and RANO, 11.7 (P = .840). Intra- and interobserver correlations were high for both contrast enhancement and FLAIR hyperintensity measurements. There was a strong concordance among the different methods in determining response and progression to irinotecan-bevacizumab. Criteria integrating FLAIR hyperintensity tended, however, to reduce response rates and progression-free survival compared with criteria considering only contrast enhancement. The 1-dimensional approach appeared to be as valid as the 2-dimensional approach.