Feasibility evaluation of hypofractionated radiotherapy with concurrent temozolomide in elderly patients with glioblastoma

Optimal managements of elderly patients with glioblastoma

Optimizing the management of elderly patients with glioblastoma is an ongoing task in neuro-oncology. The number of patients with this tumor type is gradually increasing with the aging of the population. Although available data and practice recommendations remain limited, the current strategy is maximal safe surgical resection followed by radiotherapy in combination with temozolomide. However, survival is significantly worse than that in the younger population. Surgical resection provides survival benefit in patients with good performance status. Hypofractionated radiotherapy decreases toxicities while maintaining therapeutic efficacy, thus improving treatment adherence and subsequently leading to better quality of life. The intensity of these treatments should be balanced with patient-specific factors and consideration of quality of life. This review discusses the current optimal management in terms of efficacy and safety, as well as future perspectives.

Survival benefits of hypofractionated radiotherapy combined with temozolomide or temozolomide plus bevacizumab in elderly patients with glioblastoma aged ≥ 75 years

Background and purpose

The purpose of this study was to evaluate the outcomes of elderly patients (aged ≥75 years) with newly diagnosed glioblastoma (GBM), who were treated with hypofractionated radiotherapy comprising 45 Gy in 15 fractions combined with temozolomide (TMZ) or TMZ and bevacizumab (TMZ/Bev).

Materials and methods

Between October 2007 and August 2018, 30 patients with GBM aged ≥75 years were treated with hypofractionated radiotherapy consisting of 45 Gy in 15 fractions. Twenty patients received TMZ and 10 received TMZ/Bev as upfront chemotherapy. O-6-methylguanine DNA methyltransferase (MGMT) promoter methylation status was analyzed by pyrosequencing. The cutoff value of the mean level of methylation at the 16 CpG sites was 16%.

Results

Median overall survival (OS) and progression-free survival (PFS) were 12.9 months and 9.9 months, respectively. The 1-year OS and PFS rates were 64.7 and 34.7%, respectively. Median OS and PFS did not differ significantly between patients with MGMT promoter hypermethylation (N = 11) and those with hypomethylation (N = 16) (17.4 vs. 11.8 months, p = 0.32; and 13.1 vs. 7.3 months, p = 0.11, respectively). The median OS and PFS were not significantly different between TMZ (N = 20) and TMZ/Bev (N = 10) chemotherapy (median OS: TMZ 12.9 months vs. TMZ/Bev 14.6 months, p = 0.93, median PFS: TMZ 8.5 months vs TMZ/Bev 10.0 months, p = 0.64, respectively). The median time until Karnofsky performance status (KPS) score decreasing below 60 points was 7.9 months. The best radiological responses included 11 patients with a partial response (36.7%). Grade 3/4 toxicities included leukopenia in 15 patients (50%), anorexia in 4 (13.3%), and hyponatremia during concomitant chemotherapy in 3 (10%).

Conclusion

Our hypofractionated radiotherapy regimen combined with TMZ or TMZ/Bev showed benefits in terms of OS, PFS, and KPS maintenance with acceptable toxicities in elderly patients with GBM aged ≥75 years.

Hypofractionated versus standard radiation therapy in combination with temozolomide for glioblastoma in the elderly: a meta-analysis

BACKGROUND

There is no clear consensus regarding the optimal treatment for glioblastoma (GBM) in the elderly. Hypofractionated radiation therapy (hRT) has emerged as a viable and comparable radiation regime compared to standard radiation therapy (sRT), however the survival effect of temozolomide (TMZ) with hRT is uncertain. The aim of this meta-analysis was to evaluate survival outcomes of hRT + TMZ vs sRT + TMZ in this specific demographic.

METHODS

Searches of 7 electronic databases from inception to January 2019 were conducted following the appropriate guidelines. Articles were screened against pre-specified criteria. The progression free survival (PFS) and overall survival (OS) metrics were then extracted and pooled by meta-analysis evaluating mean difference (MD).

RESULTS

A total of 7 individual comparative studies describing hRT + TMZ vs sRT + TMZ (n = 917) respectively satisfied inclusion criteria. Meta-analysis by random-effects modelling indicated that compared to sRT + TMZ, hRT + TMZ resulted in comparable PFS (MD 0.3 months; 95% CI - 2.4 to 2.9; I² = 91.7%; P-effect = 0.85) and significantly shorter OS (MD - 3.5 months; 95% CI - 6.3 to - 0.6; I² = 98.9%; P-effect = 0.02). Subgroup analysis between age definitions of elderly of > 65 vs > 70 years old both demonstrated the same significant trend with no statistical difference between the groups.

CONCLUSION

The combination of hRT + TMZ is feasible in well-selected elderly GBM cases, and appears to confer a statistically comparable PFS compared to sRT + TMZ. However, expectations that the OS with hRT + TMZ is comparable to that of sRT + TMZ in all elderly GBM presentations should be tempered. It is likely a specific subgroup of elderly GBM patients will benefit greatly from the addition of TMZ to hRT, and greater investigation is needed to identify their characteristics.

Managing an Older Adult with Cancer: Considerations for Radiation Oncologists

Older adults with cancer present a unique set of management complexities for oncologists and radiation oncologists. Prognosis and resilience to cancer treatments are notably dependent on the presence or risk of "geriatric syndromes," in addition to cancer stage and histology. Recognition, proper evaluation, and management of these conditions in conjunction with management of the cancer itself are critical and can be accomplished by utilization of various geriatric assessment tools. Here we review principles of the geriatric assessment, common geriatric syndromes, and application of these concepts to multidisciplinary oncologic treatment. Older patients may experience toxicities related to treatments that impact treatment effectiveness, quality of life, treatment-related mortality, and treatment compliance. Treatment-related burdens from radiotherapy are increasingly important considerations and include procedural demands, travel, costs, and temporary or permanent loss of functional independence. An overall approach to delivering radiotherapy to an older cancer patient requires a comprehensive assessment of both physical and nonphysical factors that may impact treatment outcome. Patient and family-centered communication is also an important part of developing a shared understanding of illness and reasonable expectations of treatment.

β-Elemene Selectively Inhibits the Proliferation of Glioma Stem-Like Cells Through the Downregulation of Notch1

Glioma is the most frequent primary central nervous system tumor. Although the current first-line medicine, temozolomide (TMZ), promotes patient survival, drug resistance develops easily. Thus, it is important to investigate novel therapeutic reagents to solidify the treatment effect. β-Elemene (bELE) is a compound from a Chinese herb whose anticancer effect has been shown in various types of cancer. However, its role in the inhibition of glioma stem-like cells (GSLCs) has not yet been reported. We studied both the in vitro and the in vivo inhibitory effect of bELE and TMZ in GSLCs and parental cells and their combined effects. The molecular mechanisms were also investigated. We also optimized the delivery methods of bELE. We found that bELE selectively inhibits the proliferation and sphere formation of GSLCs, other than parental glioma cells, and TMZ exerts its effects on parental cells instead of GSLCs. The in vivo data confirmed that the combination of bELE and TMZ worked better in the xenografts of GSLCs, mimicking the situation of tumorigenesis of human cancer. Notch1 was downregulated with bELE treatment. Our data also demonstrated that the continuous administration of bELE produces an ideal effect to control tumor progression. Our findings have demonstrated, for the first time, that bELE could compensate for TMZ to kill both GSLCs and nonstem-like cancer cells, probably improving the prognosis of glioma patients tremendously. Notch1 might be a downstream target of bELE. Therefore, our data shed light on improving the outcomes of glioma patients by combining bELE and TMZ. Stem Cells Translational Medicine 2017;6:830-839.