Outcomes in newly diagnosed elderly glioblastoma patients after concomitant temozolomide administration and hypofractionated radiotherapy

Tumor protease-activated theranostic nanoparticles for MRI-guided glioblastoma therapy

Rationale: As a cancer, Glioblastoma (GBM) is a highly lethal and difficult-to-treat. With the aim of improving therapies to GBM, we developed novel and target-specific theranostic nanoparticles (TNPs) that can be selectively cleaved by cathepsin B (Cat B) to release the potent toxin monomethyl auristatin E (MMAE). Methods: We synthesized TNPs composed of a ferumoxytol-based nanoparticle carrier and a peptide prodrug with a Cat-B-responsive linker and the tubulin inhibitor MMAE. We hypothesized that intratumoral Cat B can cleave our TNPs and release MMAE to kill GBM cells. The ferumoxytol core enables in vivo drug tracking with magnetic resonance imaging (MRI). We incubated U87-MG GBM cells with TNPs or ferumoxytol and evaluated the TNP content in the cells with transmission electron microscopy and Prussian blue staining. In addition, we stereotaxically implanted 6- to 8-week-old nude mice with U87-MG with U87-MG GBM cells that express a fusion protein of Green Fluorescence Protein and firefly Luciferase (U87-MG/GFP-fLuc). We then treated the animals with an intravenous dose of TNPs (25 mg/kg of ferumoxytol, 0.3 mg/kg of MMAE) or control. We also evaluated the combination of TNP treatment with radiation therapy. We performed MRI before and after TNP injection. We compared the results for tumor and normal brain tissue between the TNP and control groups. We also monitored tumor growth for a period of 21 days. Results: We successfully synthesized TNPs with a hydrodynamic size of 41 ± 5 nm and a zeta potential of 6 ± 3 mV. TNP-treated cells demonstrated a significantly higher iron content than ferumoxytol-treated cells (98 ± 1% vs. 3 ± 1% of cells were iron-positive, respectively). We also found significantly fewer live attached cells in the TNP-treated group (3.8 ± 2.0 px2) than in the ferumoxytol-treated group (80.0 ± 14.5 px2, p < 0001). In vivo MRI studies demonstrated a decline in the tumor signal after TNP (T2= 28 ms) but not control (T2= 32 ms) injections. When TNP injection was combined with radiation therapy, the tumor signals dropped further (T2 = 24 ms). The combination therapy of radiation therapy and TNPs extended the median survival from 14.5 days for the control group to 45 days for the combination therapy group. Conclusion: The new cleavable TNPs reported in this work accumulate in GBM, cause tumor cell death, and have synergistic effects with radiation therapy.

Radiation guidelines for gliomas

Gliomas are the most frequent primary brain tumour. The proximity of organs at risk, the infiltrating nature, and the radioresistance of gliomas have to be taken into account in the choice of prescribed dose and technique of radiotherapy. The management of glioma patients is based on clinical factors (age, KPS) and tumour characteristics (histology, molecular biology, tumour location), and strongly depends on available and associated treatments, such as surgery, radiation therapy, and chemotherapy. The knowledge of molecular biomarkers is currently essential, they are increasingly evolving as additional factors that facilitate diagnostics and therapeutic decision-making. We present the update of the recommendations of the French society for radiation oncology on the indications and the technical procedures for performing radiation therapy in patients with gliomas.

Glioblastoma in Elderly Patients: Current Management and Future Perspectives

The incidence of glioblastoma (GBM) in the elderly population is slowly increasing in Western countries. Current management includes surgery, radiation therapy (RT) and chemotherapy; however, survival is significantly worse than that observed in younger patients and the optimal treatment in terms of efficacy and safety remains a matter of debate. Surgical resection is often employed as initial treatment for elderly patients with GBM, although the survival benefit is modest. Better survival has been reported in elderly patients treated with RT compared with those receiving supportive care alone, with similar survival outcome for patients undergoing standard RT (60 Gy over 6 weeks) and hypofractionated RT (25⁻40 Gy in 5⁻15 daily fractions). Temozolomide, an alkylating agent, may represent an effective and safe therapy in patients with promoter methylation of O⁶-methylguanine-DNA-methyltransferase (MGMT) gene which is predictor of responsiveness to alkylating agents. An abbreviated course of RT, 40 Gy in 15 daily fractions in combination with adjuvant and concomitant temozolomide has emerged as an effective treatment for patients aged 65 years old or over with GBM. Results of the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG CE6) and European Organization for Research and Treatment of Cancer (EORTC 26062/22061) randomized study of short-course RT with or without concurrent and adjuvant temozolomide have demonstrated a significant improvement in progression-free survival and overall survival for patients receiving RT and temozolomide over RT alone, without impairing either quality of life or functional status. Although combined chemoradiation has become the recommended treatment in fit elderly patients with GBM, several questions remain unanswered, including the survival impact of chemoradiation in patients with impaired neurological status, advanced age (>75⁻80 years old), or for those with severe comorbidities. In addition, the efficacy and safety of alternative therapeutic approaches according to the methylation status of the O⁶-methylguanine-DNA methyl-transferase (MGMT) gene promoter need to be explored in future trials.

[Hypofractioned radiotherapy in elderly patient with glioblastoma]

Glioblastoma is the most frequent primary brain tumor, with more than half of all patients being at least 65 years old. The treatment of the elderly in this pathology represents therefore a considerable challenge for oncologists and radiation therapists. However, in most clinical trials, age is a non-eligible criterial. In the last ten years, geriatric therapeutic trials have been multiplied. The treatment of glioblastoma consists of adjuvant chemoradiotherapy. In elderly patients, the evaluation of performans status and the molecular characteristics of the tumor are important factors in order to propose the appropriate treatment in terms of efficacy and toxicity.

Leptomeningeal enhancement on preoperative brain MRI in patients with glioblastoma and its clinical impact

AIM

Leptomeningeal enhancement (LME) on preoperative brain magnetic resonance imaging (MRI) does not always indicate leptomeningeal seeding (LMS). With Stupp's regimen, authors have treated glioblastoma patients with LME on preoperative brain MRI but here we tried to find the clinical impact of LME.

METHODS

From 2005 to 2015, 290 patients with glioblastoma have been treated with Stupp's regimen at Samsung Medical Center. Among these, 33 patients showed LME on preoperative brain MRI. We compared the clinical outcomes between the patients with or without LME on preoperative brain MRI and analyzed the clinical results according to changes of LME at following MRI.

RESULTS

The median survival was 23 months, and 2-year overall survival (OS) and disease-free survival (DFS) rate was 46.3% and 19.6%, respectively. Prognostic factors for OS and DFS were Karnofsky performance status, extent of resection and adjuvant chemotherapy. MGMT promoter methylation status was a significant prognostic factor for DFS. However, LME was not a significant prognostic factor for OS (P = 0.156) or DFS (P = 0.193). Among the 33 patients with LME on preoperative MRI, 21 (63.6%) showed persistent LME at the next MRI. A statistically significant difference in 2-year survival was evident between patients with and without persistent LME (OS, 17.3% and 70.1%, respectively, P = 0.044; DFS, 5.3% and 54.0%, respectively, P = 0.006). The most common pattern of failure was local recurrence. However, patients with persistent LME displayed a higher incidence of LMS than patients without LME.

CONCLUSION

LME on preoperative brain MRI did not affect the clinical results in glioblastoma patients treated with the Stupp's regimen. However, persistence of LME was associated with poor survival and high possibility of LMS. For these patients, the postoperative adjuvant treatment should focus on palliative aim or more aggressive treatment scheme should be followed to overcome the disastrous results.

Recurrent glioblastomas in the elderly after maximal first-line treatment: does preserved overall condition warrant a maximal second-line treatment?

A growing literature supports maximal safe resection followed by standard combined chemoradiotherapy (i.e. maximal first-line therapy) for selected elderly glioblastoma patients. To assess the prognostic factors from recurrence in elderly glioblastoma patients treated by maximal safe resection followed by standard combined chemoradiotherapy as first-line therapy. Multicentric retrospective analysis comparing the prognosis and optimal oncological management of recurrent glioblastomas between 660 adult patients aged of < 70 years (standard group) and 117 patients aged of ≥70 years (elderly group) harboring a supratentorial glioblastoma treated by maximal first-line therapy. From recurrence, both groups did not significantly differ regarding Karnofsky performance status (KPS) (p = 0.482). Oncological treatments from recurrence significantly differed: patients of the elderly group received less frequently oncological treatment from recurrence (p < 0.001), including surgical resection (p < 0.001), Bevacizumab therapy (p < 0.001), and second line chemotherapy other than Temozolomide (p < 0.001). In multivariate analysis, Age ≥70 years was not an independent predictor of overall survival from recurrence (p = 0.602), RTOG-RPA classes 5-6 (p = 0.050) and KPS at recurrence <70 (p < 0.001), available in all cases, were independent significant predictors of shorter overall survival from recurrence. Initial removal of ≥ 90% of enhancing tumor (p = 0.004), initial completion of the standard combined chemoradiotherapy (p = 0.007), oncological treatment from recurrence (p < 0.001), and particularly surgical resection (p < 0.001), Temozolomide (p = 0.046), and Bevacizumab therapy (p = 0.041) were all significant independent predictors of longer overall survival from recurrence. Elderly patients had substandard care from recurrence whereas age did not impact overall survival from recurrence contrary to KPS at recurrence <70. Treatment options from recurrence should include repeat surgery, second line chemotherapy and anti-angiogenic agents.

Elderly patients with newly diagnosed glioblastoma: can preoperative imaging descriptors improve the predictive power of a survival model?

The purpose of this study was to identify independent prognostic factors among preoperative imaging features in elderly glioblastoma patients and to evaluate whether these imaging features, in addition to clinical features, could enhance the predictive power of survival models. This retrospective study included 108 patients ≥65 years of age with newly diagnosed glioblastoma. Preoperative clinical features (age and KPS), postoperative clinical features (extent of surgery and postoperative treatment), and preoperative MRI features were assessed. Univariate and multivariate cox proportional hazards regression analyses for overall survival were performed. The integrated area under the receiver operating characteristic curve (iAUC) was calculated to evaluate the added value of imaging features in the survival model. External validation was independently performed with 40 additional patients ≥65 years of age with newly diagnosed glioblastoma. Eloquent area involvement, multifocality, and ependymal involvement on preoperative MRI as well as clinical features including age, preoperative KPS, extent of resection, and postoperative treatment were significantly associated with overall survival on univariate Cox regression. On multivariate analysis, extent of resection and ependymal involvement were independently associated with overall survival and preoperative KPS showed borderline significance. The model with both preoperative clinical and imaging features showed improved prediction of overall survival compared to the model with preoperative clinical features (iAUC, 0.670 vs. 0.600, difference 0.066, 95% CI 0.021-0.121). Analysis of the validation set yielded similar results (iAUC, 0.790 vs. 0.670, difference 0.123, 95% CI 0.021-0.260), externally validating this observation. Preoperative imaging features, including eloquent area involvement, multifocality, and ependymal involvement, in addition to clinical features, can improve the predictive power for overall survival in elderly glioblastoma patients.

A Novel Theranostic Strategy for MMP-14-Expressing Glioblastomas Impacts Survival

Glioblastoma (GBM) has a dismal prognosis. Evidence from preclinical tumor models and human trials indicates the role of GBM-initiating cells (GIC) in GBM drug resistance. Here, we propose a new treatment option with tumor enzyme-activatable, combined therapeutic and diagnostic (theranostic) nanoparticles, which caused specific toxicity against GBM tumor cells and GICs. The theranostic cross-linked iron oxide nanoparticles (CLIO) were conjugated to a highly potent vascular disrupting agent (ICT) and secured with a matrix-metalloproteinase (MMP-14) cleavable peptide. Treatment with CLIO-ICT disrupted tumor vasculature of MMP-14-expressing GBM, induced GIC apoptosis, and significantly impaired tumor growth. In addition, the iron core of CLIO-ICT enabled in vivo drug tracking with MR imaging. Treatment with CLIO-ICT plus temozolomide achieved tumor remission and significantly increased survival of human GBM-bearing mice by more than 2-fold compared with treatment with temozolomide alone. Thus, we present a novel therapeutic strategy with significant impact on survival and great potential for clinical translation. Mol Cancer Ther; 16(9); 1909-21. ©2017 AACR.

Hypofractionated short-course radiotherapy in elderly patients with glioblastoma multiforme: an analysis of the National Cancer Database

For elderly patients with glioblastoma multiforme (GBM), randomized trials have shown similar survival with hypofractionated short-course radiotherapy (SCRT) compared to conventionally fractionated long-course radiotherapy (LCRT). We evaluated the adoption of SCRT along with associated factors and survival in a national patient registry. Using the National Cancer Data Base (NCDB), we identified patients aged ≥70 years with GBM, diagnosed between 1998 and 2011, who received SCRT (34-42 Gy in 2.5-3.4 Gy fractions), or LCRT (58-63 Gy in 1.8-2.0 Gy fractions). Crude and adjusted hazard ratios (HR) were calculated using Cox regression modeling. 4598 patients were identified, 304 (6.6%) in the SCRT group and 4294 (93.4%) in the LCRT group. Median follow-up was 8.4 months. Median age was 78 versus 75 years, respectively (P < 0.0001). Patients who received SCRT had higher Charlson-Deyo comorbidity scores versus LCRT (score of ≥2: 16.9% vs. 10.8%, respectively; P = 0.006), and were more likely to be female (53.0% vs. 44.6%, P = 0.005). Patients who received SCRT were less likely to undergo chemotherapy (42.8% vs. 79.3%, P < 0.0001), more likely to undergo biopsy only (34.5% vs. 19.5%, P < 0.0001), and more likely to receive treatment at academic/research programs (49.2% vs. 37.2%, P = 0.0001). Median survival was 4.9 months versus 8.9 months, respectively (P < 0.0001). The survival detriment with SCRT persisted on multivariable analysis [HR 1.51 (95% CI: 1.33-1.73, P < 0.0001)], adjusting for age, gender, race, comorbidities, diagnosis year, facility type, surgery, and chemotherapy. In conclusion, hypofractionated SCRT was associated with worse survival compared to conventionally fractionated LCRT for elderly patients with GBM. Patients who received SCRT were older with worse comorbidities, and were less likely to undergo chemotherapy or resection.

[Guidelines for the radiotherapy of gliomas]

Gliomas are the most frequent primary brain tumours. Treating these tumours is difficult because of the proximity of organs at risk, infiltrating nature, and radioresistance. Clinical prognostic factors such as age, Karnofsky performance status, tumour location, and treatments such as surgery, radiation therapy, and chemotherapy have long been recognized in the management of patients with gliomas. Molecular biomarkers are increasingly evolving as additional factors that facilitate diagnosis and therapeutic decision-making. These practice guidelines aim at helping in choosing the best treatment, in particular radiation therapy.

Hypofractionated radiation therapy versus standard fractionated radiation therapy with concurrent temozolomide in elderly patients with newly diagnosed glioblastoma

PURPOSE

Adjuvant hypofractionated radiation therapy (HRT) for elderly patients with newly diagnosed glioblastoma (GBM) is a reasonable option compared with standard fractionation radiation therapy (SFRT). Outcomes in patients receiving HRT in the presence of temozolomide (TMZ) compared with SFRT with TMZ are unclear. We examined HRT for GBM with TMZ in comparison to SFRT with TMZ.

METHODS AND MATERIALS

We conducted a retrospective analysis of patients ≥60 years of age with newly diagnosed GBM who received SFRT or HRT from 1994 to 2014 in the postoperative setting. Inclusion criteria included SFRT (60 Gy/30 fractions or 59.4 Gy/33 fractions) versus HRT (40 Gy/15 fractions).

RESULTS

In this cohort, 158 patients were treated with SFRT versus 26 with HRT. Median survival in patients receiving SFRT compared with HRT was 430 and 475 days (P = .550), respectively. Ninety-five percent of the SFRT patients received TMZ versus 100% of those treated with HRT. Patients receiving HRT were older (median, 72 vs 66 years). All HRT patients were treated with the intensity modulated radiation therapy (IMRT) technique versus SFRT, in which 57% had IMRT. Multivariate Cox regression showed decreased overall survival (OS) associated with patient age >70 (hazard ratio [HR], 1.84), lower Karnofsky performance status (HR, 5.25), biopsy versus surgical resection (HR, 4.18), radiation therapy planning technique 3- or 2-dimensional planning versus IMRT (HR, 1.91; HR, 3.40, respectively). Analysis restricted to patients receiving IMRT-based planning showed no difference in OS between HRT and SFRT. For patients receiving TMZ, there was no survival difference between those treated with HRT and those treated with SFRT.

CONCLUSIONS

Elderly GBM patients receiving HRT and those receiving SFRT had similar OS. Subset analysis patients receiving concurrent TMZ showed no difference in OS between the HRT and SFRT groups.

Hypofractionated versus standard radiation therapy with or without temozolomide for older glioblastoma patients

PURPOSE

Older patients with newly diagnosed glioblastoma have poor outcomes, and optimal treatment is controversial. Hypofractionated radiation therapy (HRT) is frequently used but has not been compared to patients receiving standard fractionated radiation therapy (SRT) and temozolomide (TMZ).

METHODS AND MATERIALS

We conducted a retrospective analysis of patients ≥65 years of age who received radiation for the treatment of newly diagnosed glioblastoma from 1994 to 2013. The distribution of clinical covariates across various radiation regimens was analyzed for possible selection bias. Survival was calculated using the Kaplan-Meier method. Comparison of hypofractionated radiation (typically, 40 Gy/15 fractions) versus standard fractionation (typically, 60 Gy/30 fractions) in the setting of temozolomide was conducted using Cox regression and propensity score analysis.

RESULTS

Patients received SRT + TMZ (n=57), SRT (n=35), HRT + TMZ (n=34), or HRT (n=9). Patients receiving HRT were significantly older (median: 79 vs 69 years of age; P<.001) and had worse baseline performance status (P<.001) than those receiving SRT. On multivariate analysis, older age (adjusted hazard ratio [AHR]: 1.06; 95% confidence interval [CI]: 1.01-1.10, P=.01), lower Karnofsky performance status (AHR: 1.02; 95% CI: 1.01-1.03; P=.01), multifocal disease (AHR: 2.11; 95% CI: 1.23-3.61, P=.007), and radiation alone (vs SRT + TMZ; SRT: AHR: 1.72; 95% CI: 1.06-2.79; P=.03; HRT: AHR: 3.92; 95% CI: 1.44-10.60, P=.007) were associated with decreased overall survival. After propensity score adjustment, patients receiving HRT with TMZ had similar overall survival compared with those receiving SRT with TMZ (AHR: 1.10, 95% CI: 0.50-2.4, P=.82).

CONCLUSIONS

With no randomized data demonstrating equivalence between HRT and SRT in the setting of TMZ for glioblastoma, significant selection bias exists in the implementation of HRT. Controlling for this bias, we observed similar overall survival for HRT and SRT with concurrent TMZ among elderly patients, suggesting the need for a randomized trial to compare these regimens directly.

[Elderly patients with glioblastoma: state of the art]

The incidence of glioblastoma increases with age, with a median age, at diagnosis, of 65 years. Indeed, the optimization of standard of care of elderly glioblastoma patients in an aging population in Western countries becomes crucial. The age remains the main prognostic factor of glioblastoma. Survival among elderly patients is significantly less than among younger patients. The median survival of elderly glioblastoma patients is generally inferior to 6 months. More aggressive tumor behavior, less aggressive treatments, increased toxicity of therapies and more unfavorable clinical factors and comorbidities could explain a higher severity of the disease in the elderly. The balance between treatment efficacy and quality of life is a major focus because of the shorter life expectancy of patients. The standard of care of glioblastoma in elderly patients remains controversial. Large optimal resection, when achievable, should be preferred to biopsy. Survival is longer after adjuvant radiotherapy, either normofractionated over 6-weeks course or hypofractionated over 3-weeks course, for patients with good clinical status. Hypofractionation is often preferred because of shorter procedure. Chemotherapy alone with temozolomide can be proposed to patients with methylated MGMT promoter. A phase III randomized study, testing short-course adjuvant radiotherapy with or without temozolomide in elderly patients with good clinical status, is ongoing.

The clinico-oncologic outcomes of elderly patients with glioblastoma after surgical resection followed by concomitant chemo-radiotherapy

Background

There have been controversies in the treatment of elderly patients with glioblastoma. We introduce the outcome of the treatment of elderly patients with glioblastoma comparing with younger patients.

Methods

The author's hospital database was used to identify patients with histologically confirmed glioblastoma after surgery between January 2006 and December 2013. Forty-eight patients (control group) were under age 65 and 16 patients (elderly group) were aged 65 years or over at the time of surgery.

Results

The median age of the elderly group was 71 years and control group was 50 years. Mean number of medical comorbidities was 1.8 in the elderly group vs. 0.5 in the control group. The median progression free survival (PFS) was 5.6 months and the median overall survival (OS) was 19.9 months in all patients. The elderly group had a median PFS of 4.2 months vs. 8 months for the control group (log-rank test, p=0.762). Median OS was 8.2 months in the elderly group vs. 20.9 months in the control group (log-rank test, p=0.457). Major complications occurred in 5 cases (7.8%) for all patients. The ratio of completion of concomitant chemo-radiotherapy (CCRT) was 81.3% and was the same between the two groups. In multivariable analysis, extent of resection (p=0.034) and completion of CCRT (p=0.023) were statistically significant, independent prognostic factors only for PFS in all patients by Cox proportional hazards model. Age was not an independent prognostic factor. As for OS, there was no significant factor.

Conclusion

Surgical resection and CCRT were well tolerated in elderly patients with glioblastoma, and maximal safe resection followed by timely CCRT could improve clinic-oncologic outcomes.

Radiation therapy for older adults with glioblastoma: radical treatment, palliative treatment, or no treatment at all?

The incidence of glioblastoma in older adults has increased over the last few decades. Current treatment includes surgery, radiotherapy, and chemotherapy, but optimal disease management remains a matter of debate. Both standard (60 Gy in 30 daily fractions) and hypofractionated radiotherapy (30-40 Gy in 10-15 daily fractions) have been employed with a similar survival benefit. Recent randomized studies indicate that chemotherapy with the alkylating agent temozolomide is a safe and effective therapeutic option for patients aged 60 years or older with newly diagnosed glioblastoma, suggesting that it should be a sufficient treatment for patients presenting with a methylated O6-methylguanine-DNA methyltransferase (MGMT) promoter gene. The addition of concomitant temozolomide chemotherapy, adjuvant temozolomide chemotherapy, or both to postoperative radiotherapy, which is the standard treatment for adults with glioblastoma, has been associated with a survival benefit for older patients with a good performance status; however, aggressive treatment in this population may be associated with a high risk of neurological toxicity and deterioration of quality of life. Survival stratification according to age, MGMT promoter methylation status, and neurological status may be useful for clinical decision making and designing randomized trials for adequately evaluating the optimal combination of radiotherapy and chemotherapy for older patients with glioblastoma.

Treatment of malignant gliomas in elderly patients: a concise overview of the literature

Gliomas are the most frequent primary brain tumors and the incidence data has increased in the elderly population. Unfortunately, prospective studies on this population are few and so the right treatment is unknown. In the elderly patients no standard treatment has been established and therefore the optimal treatment should be individualized. We performed a review analyzing the prognostic and predictive factors, the clinical studies, and the correct management of this population.