Treatment of recurrent glioblastoma: state-of-the-art and future perspectives

Radio-pathomic maps of glioblastoma identify phenotypes of non-enhancing tumor infiltration associated with bevacizumab treatment response

BACKGROUND

Autopsy-based radio-pathomic maps of glioma pathology have shown substantial promise inidentifying areas of non-enhancing tumor presence, which may be able to differentiate subsets of patients that respond favorably to treatments such as bevacizumab that have shown mixed efficacy evidence. We tested the hypthesis that phenotypes of non-enhancing tumor fronts can distinguish between glioblastoma patients that will respond favorably to bevacizumab and will visually capture treatment response.

METHODS

T1, T1C, FLAIR, and ADC images were used to generate radio-pathomic maps of tumor characteristics for 79 pre-treatment patients with a primary GBM or high-grade IDH1-mutant astrocytoma for this study. Novel phenotyping (hypercellular, hypocellular, hybrid, or well-circumscribed front) of the non-enhancing tumor front was performed on each case. Kaplan Meier analyses were then used to assess differences in survival and bevacizumab efficacy between phenotypes. Phenotype compartment segmentations generated longitudinally for a subset of 26 patients over the course of bevacizumab treatment, where a mixed effect model was used to detect longitudinal changes.

RESULTS

Well-Circumscribed patients showed significant/trending increases in survival compared to Hypercellular Front (HR = 2.0, p = 0.05), Hypocellular Front (HR = 2.02, p = 0.03), and Hybrid Front tumors (HR = 1.75, p = 0.09). Only patients with hypocellular or hybrid fronts showed significant survival benefits from bevacizumab treatment (HR = 2.35, p = 0.02; and HR = 2.45, p = 0.03, respectively). Hypocellular volumes decreased by an average 50.52 mm3 per day of bevacizumab treatment (p = 0.002).

CONCLUSION

Patients with a hypocellular tumor front identified by radio-pathomic maps showed improved treatment efficacy when treated with bevacizumab, and reducing hypocellular volumes over the course of treatment may indicate treatment response.

Radio-pathomic maps of glioblastoma identify phenotypes of non-enhancing tumor infiltration associated with bevacizumab treatment response

Background

Autopsy-based radio-pathomic maps of glioma pathology have shown substantial promise inidentifying areas of non-enhancing tumor presence, which may be able to differentiate subsets of patients that respond favorably to treatments such as bevacizumab that have shown mixed efficacy evidence. We tested the hypthesis that phenotypes of non-enhancing tumor fronts can distinguish between glioblastoma patients that will respond favorably to bevacizumab and will visually capture treatment response.

Methods

T1, T1C, FLAIR, and ADC images were used to generate radio-pathomic maps of tumor characteristics for 79 pre-treatment patients with a primary GBM or high-grade IDH1-mutant astrocytoma for this study. Novel phenotyping (hypercellular, hypocellular, hybrid, or well-circumscribed front) of the non-enhancing tumor front was performed on each case. Kaplan Meier analyses were then used to assess differences in survival and bevacizumab efficacy between phenotypes. Phenotype compartment segmentations generated longitudinally for a subset of 26 patients over the course of bevacizumab treatment, where a mixed effect model was used to detect longitudinal changes.

Results

Well-Circumscribed patients showed significant/trending increases in survival compared to Hypercellular Front (HR = 2.0, p = 0.05), Hypocellular Front (HR = 2.02, p = 0.03), and Hybrid Front tumors (HR = 1.75, p = 0.09). Only patients with hypocellular or hybrid fronts showed significant survival benefits from bevacizumab treatment (HR = 2.35, p = 0.02; and HR = 2.45, p = 0.03, respectively). Hypocellular volumes decreased by an average 50.52 mm3 per day of bevacizumab treatment (p = 0.002).

Conclusion

Patients with a hypocellular tumor front identified by radio-pathomic maps showed improved treatment efficacy when treated with bevacizumab, and reducing hypocellular volumes over the course of treatment may indicate treatment response.

Bioactive compounds from Actinidia arguta fruit as a new strategy to fight glioblastoma

In recent years, there has been a significant demand for natural products as a mean of disease prevention or as an alternative to conventional medications. The driving force for this change is the growing recognition of the abundant presence of valuable bioactive compounds in natural products. On recent years Actinia arguta fruit, also known as kiwiberry, has attracted a lot of attention from scientific community due to its richness in bioactive compounds, including phenolic compounds, organic acids, vitamins, carotenoids and fiber. These bioactive compounds contribute to the fruit's diverse outstanding biological activities such as antioxidant, anti-inflammatory, neuroprotective, immunomodulatory, and anti-cancer properties. Due to these properties, the fruit may have the potential to be used in the treatment/prevention of various types of cancer, including glioblastoma. Glioblastoma is the most aggressive form of brain cancer, displaying 90 % of recurrence rate within a span of 2 years. Despite the employment of an aggressive approach, the prognosis remains unfavorable, emphasizing the urgent requirement for the development of new effective treatments. The preclinical evidence suggests that kiwiberry has potential impact on glioblastoma by reducing the cancer self-renewal, modulating the signaling pathways involved in the regulation of the cell phenotype and metabolism, and influencing the consolidation of the tumor microenvironment. Even though, challenges such as the imprecise composition and concentration of bioactive compounds, and its low bioavailability after oral administration may be drawbacks to the development of kiwiberry-based treatments, being urgent to ensure the safety and efficacy of kiwiberry for the prevention and treatment of glioblastoma. This review aims to highlight the potential impact of A. arguta bioactive compounds on glioblastoma, providing novel insights into their applicability as complementary or alternative therapies.

Intraoperative radiotherapy in recurrent IDH-wildtype glioblastoma with gross total resection: A single-center retrospective study

BACKGROUND

Isocitrate dehydrogenase-wildtype (IDHwt) glioblastoma (GBM) is one of the most aggressive primary brain tumors. The recurrence of GBM is almost inevitable. As an adjuvant option to surgery, intraoperative radiotherapy (IORT) is gaining increasing attention in the treatment of glioma. This study is aimed to evaluate the therapeutic efficacy of IORT on recurrent IDHwt GBM.

METHODS

In total, 34 recurrent IDHwt GBM patients who received a second surgery were included in the analysis (17 in the surgery group and 17 in the surgery + IORT group).

RESULTS

The progression-free survival and overall survival after the second surgery were defined as PFS2 and OS2, respectively. The median PFS2 was 7.3 months (95% CI: 6.3-10.5) and 10.6 months (95% CI: 9.3-14.6) for those patients who received surgery and surgery + IORT, respectively. Patients in the surgery + IORT group also had a longer OS2 (12.8 months, 95% CI: 11.4-17.2) than those in the surgery group (9.3 months, 95% CI: 8.9-12.9). The Kaplan-Meier survival curves, analyzed by log-rank test, revealed a statistically significant difference in PFS2 and OS2 between both groups, suggesting that IORT plays an active role in the observed benefits for PFS2 and OS2. The effects of IORT on PFS2 and OS2 were further confirmed by multivariate Cox hazards regression analysis. Two patients in the surgery group developed distant glioma metastases, and no radiation-related complications were observed in the IORT group.

CONCLUSIONS

This study suggests that low-dose IORT may improve the prognosis of recurrent IDHwt GBM patients. Future prospective large-scale studies are needed to validate the efficacy and safety of IORT.

Impact of Reirradiation Utilizing Fractionated Stereotactic Radiotherapy for Recurrent Glioblastoma

BACKGROUND

Patients with recurrent glioblastoma (GBM) have limited treatment options. This study determined whether patients with recurrent GBM treated with initial radiation/temozolomide (TMZ) and reirradiation using fractionated stereotactic radiotherapy (FSRT) had improved outcomes.

MATERIALS AND METHODS

We identified 95 patients with recurrent GBM, 50 of whom underwent FSRT at recurrence and 45 who had systemic treatment only (control). The median total FSRT dose at the time of GBM recurrence was 30 Gy in five fractions of the gadolinium-enhanced tumor only.

RESULTS

With a median follow-up of 18 months, the progression-free survival (PFS) and overall survival (OS) following initial GBM diagnosis were longer in the reirradiation group compared to the control group (13.5 vs. 7.5 months [p=0.001] and 24.6 vs. 12.6 months [p<0.001], respectively). For patients who underwent reirradiation, the median time interval between the end of the initial radiation and reirradiation was 15.2 months. The median OS after GBM recurrence was longer in the reirradiation group versus the control group (9.9 vs. 3.5 months [p<0.001]), with a one-year OS survival rate of 22%. The hazard ratio for death of patients in the reirradiation group was 0.31 [0.19-0.50]. The reirradiation group had a higher percentage of patients who received bevacizumab (BEV, 62.0% vs. 28.9%, p=0.002) and a lower percentage of patients whose TMZ was discontinued due to toxicity (8.0% vs. 28.9%, p=0.017) compared to the control group.

CONCLUSIONS

Reirradiation utilizing FSRT was associated with improved PFS and OS after GBM recurrence compared to the control group who did not receive additional irradiation.

Diagnostic performance of perfusion-weighted imaging combined with serum MMP-2 and -9 levels in tumor recurrence after postoperative concomitant chemoradiotherapy of glioblastoma

OBJECTIVE

To evaluate diagnostic accuracy of dynamic susceptibility contrast- perfusion weighted imaging (DSC-PWI) combined with serum MMP-2 and -9 levels in differentiating recurrent glioblastoma (GBM).

METHODS

We enrolled a total of 220 GBM patients, including recurrent cases (n = 150) and non-recurrent cases (n = 70) after postoperative concomitant chemoradiotherapy. All patients performed preoperative and follow-up DSC-PWI, and two parameters [normalized cerebral blood volume (nCBV) and cerebral blood flow (nCBF)] were obtained. Preoperative serum levels of MMP-2 and MMP-9 were detected using ELISA. The diagnostic performance was evaluated by analyzing receiver operating characteristic (ROC) and area under the curve (AUC).

RESULTS

At baseline, the recurrence patients had higher nCBF and nCBV than the non-recurrence patients, accompanying by the increased MMP-2 and MMP-9 levels in serum. Serum MMP-2 level were positively associated with MMP-9 in recurrent patients. In patients classified as recurrence, both MMP-9 and MMP-2 in serum had a significant correlation with nCBV and nCBF. A sensitivity and specificity of nCBF for recurrence vs. non-recurrence were 94.29% and 63.33%, respectively. nCBV also could provide high discrimination between recurrence and non-recurrence patients (sensitivity: 84.29%, specificity: 62.67%, AUC: 0.821). In ROC analyses, both MMP-2 and MMP-9 distinguished recurrence from non-recurrence with AUC values of 0.883 and 0.900, respectively. Finally, the combination of DSC-PWI parameters (nCBF and nCBV) and serum MMP-2 and -9 levels showed much better discrimination capacity between recurrence and non-recurrence patients with a sensitivity of 92.86%, specificity of 79.33% and AUC of 0.899.

CONCLUSION

The combination of DSC-PWI parameters together with serum MMP-2 and -9 levels offered an attractive approach to noninvasively distinguish recurrence after postoperative radiotherapy of GBM.

Natural Compounds in Liposomal Nanoformulations of Potential Clinical Application in Glioblastoma

Glioblastoma (GBM) is the most common malignant neoplasm in adults among all CNS gliomas, with the 5-year survival rate being as low as 5%. Among nanocarriers, liposomal nanoformulations are considered as a promising tool for precise drug delivery. The herein presented study demonstrates the possibility of encapsulating four selected natural compounds (curcumin, bisdemethoxycurcumin, acteoside, and orientin) and their mixtures in cationic liposomal nanoformulation composed of two lipid types (DOTAP:POPC). In order to determine the physicochemical properties of the new drug carriers, specific measurements, including particle size, Zeta Potential, and PDI index, were applied. In addition, NMR and EPR studies were carried out for a more in-depth characterization of nanoparticles. Within biological research, the prepared formulations were evaluated on T98G and U-138 MG glioblastoma cell lines in vitro, as well as on a non-cancerous human lung fibroblast cell line (MRC-5) using the MTT test to determine their potential as anticancer agents. The highest activity was exhibited by liposome-entrapped acteoside towards the T98G cell line with IC₅₀ equal 2.9 ± 0.9 µM after 24 hours of incubation. Noteworthy, curcumin and orientin mixture in liposomal formulation exhibited a synergistic effect against GBM. Moreover, the impact on the expression of apoptosis-associated proteins (p53 and Caspase-3) of acteoside as well as curcumin and orientin mixture, as the most potent agents, was assessed, showing nearly 40% increase as compared to control U-138 MG and T98G cells. It should be emphasized that a new and alternative method of extrusion of the studied liposomes was developed.

Potent predictive CpG signature for temozolomide response in non-glioma-CpG island methylator phenotype glioblastomas with methylated MGMT promoter

Aim: We aimed to identify potent CpG signatures predicting temozolomide (TMZ) response in glioblastomas (GBMs) that do not have the glioma-CpG island methylator phenotype (G-CIMP) but have a methylated promoter of MGMT (me MGMT). Materials & methods: Different datasets of non-G-CIMP me MGMT GBMs with molecular and clinical data were analyzed. Results: A panel of 77 TMZ efficacy-related CpGs and a seven-CpG risk signature were identified and validated for distinguishing differential outcomes to radiotherapy plus TMZ versus radiotherapy alone in non-G-CIMP me MGMT GBMs. An integrated classification scheme was also proposed for refining a MGMT-based TMZ-guiding approach in all G-CIMP-GBMs. Conclusion: The CpG signatures may serve as promising predictive biomarker candidates for guiding optimal TMZ usage in non-G-CIMP me MGMT GBMs.

Detection of perillyl alcohol and its metabolite perillic acid in postsurgical glioblastoma tissue after intranasal administration of NEO100: illustrative case

BACKGROUND

Intranasal delivery of NEO100, a pharmaceutical-grade version of the natural monoterpene perillyl alcohol (POH), is undergoing clinical phase IIa testing as a treatment for glioblastoma (GBM). However, so far there is no evidence that intranasal delivery of NEO100 indeed results in POH reaching intracranial malignancies in a patient.

OBSERVATIONS

After surgical removal of her recurrent GBM tumor, a patient received daily intranasal NEO100 therapy for more than 3 years before a second recurrence emerged. At that time, a final dose of NEO100 was given shortly before the tumor tissue was surgically removed, and the tissue was processed for high-performance liquid chromatography analysis of POH and its primary metabolite, perillic acid (PA). Both molecules could readily be detected in the tumor tissue.

LESSONS

This is the first demonstration of POH and PA in brain tumor tissue from any patient. It reveals that intranasal administration of NEO100 is a valid approach to achieve delivery of this agent to a brain tumor. In view of the noninvasive and safe nature of this method, along with tentative indications of activity, our findings add confidence to the notion that intranasal administration of NEO100 holds potential as a new treatment option for brain-localized malignancies.

Tumor-Associated Microenvironment of Adult Gliomas: A Review

The glioma-associated tumor microenvironment involves a multitude of different cells ranging from immune cells to endothelial, glial, and neuronal cells surrounding the primary tumor. The interactions between these cells and glioblastoma (GBM) have been deeply investigated while very little data are available on patients with lower-grade gliomas. In these tumors, it has been demonstrated that the composition of the microenvironment differs according to the isocitrate dehydrogenase status (mutated/wild type), the presence/absence of codeletion, and the expression of specific alterations including H3K27 and/or other gene mutations. In addition, mechanisms by which the tumor microenvironment sustains the growth and proliferation of glioma cells are still partially unknown. Nonetheless, a better knowledge of the tumor-associated microenvironment can be a key issue in the optic of novel therapeutic drug development.

Pharmacotherapeutic Treatment of Glioblastoma: Where Are We to Date?

The clinical management of glioblastoma (GBM) is still bereft of treatments able to significantly improve the poor prognosis of the disease. Despite the extreme clinical need for novel therapeutic drugs, only a small percentage of patients with GBM benefit from inclusion in a clinical trial. Moreover, often clinical studies do not lead to final interpretable conclusions. From the mistakes and negative results obtained in the last years, we are now able to plan a novel generation of clinical studies for patients with GBM, allowing the testing of multiple anticancer agents at the same time. This assumes critical importance, considering that, thanks to improved knowledge of altered molecular mechanisms related to the disease, we are now able to propose several potential effective compounds in patients with both newly diagnosed and recurrent GBM. Among the novel compounds assessed, the initially great enthusiasm toward trials employing immune checkpoint inhibitors (ICIs) was disappointing due to the negative results that emerged in three randomized phase III trials. However, novel biological insights into the disease suggest that immunotherapy can be a convincing and effective treatment in GBM even if ICIs failed to prolong the survival of these patients. In this regard, the most promising approach consists of engineered immune cells such as chimeric antigen receptor (CAR) T, CAR M, and CAR NK alone or in combination with other treatments. In this review, we discuss several issues related to systemic treatments in GBM patients. First, we assess critical issues toward the planning of clinical trials and the strategies employed to overcome these obstacles. We then move on to the most relevant interventional studies carried out on patients with previously untreated (newly diagnosed) GBM and those with recurrent and pretreated disease. Finally, we investigate novel immunotherapeutic approaches with special emphasis on preclinical and clinical data related to the administration of engineered immune cells in GBM.

Glioblastoma Microenvironment: From an Inviolable Defense to a Therapeutic Chance

Glioblastoma is an aggressive tumor and is associated with a dismal prognosis. The availability of few active treatments as well as the inexorable recurrence after surgery are important hallmarks of the disease. The biological behavior of glioblastoma tumor cells reveals a very complex pattern of genomic alterations and is partially responsible for the clinical aggressiveness of this tumor. It has been observed that glioblastoma cells can recruit, manipulate and use other cells including neurons, glial cells, immune cells, and endothelial/stromal cells. The final result of this process is a very tangled net of interactions promoting glioblastoma growth and progression. Nonetheless, recent data are suggesting that the microenvironment can also be a niche in which glioblastoma cells can differentiate into glial cells losing their tumoral phenotype. Here we summarize the known interactions between micro-environment and glioblastoma cells highlighting possible therapeutic implications.

Cell‑based immunotherapy of glioblastoma multiforme (Review)

Glioblastoma multiforme (GBM) is the most aggressive and lethal primary glial brain tumor. It has an unfavorable prognosis and relatively ineffective treatment protocols, with the median survival of patients being ~15 months. Tumor resistance to treatment is associated with its cancer stem cells (CSCs). At present, there is no medication or technologies that have the ability to completely eradicate CSCs, and immunotherapy (IT) is only able to prolong the patient's life. The present review aimed to investigate systemic solutions for issues associated with immunosuppression, such as ineffective IT and the creation of optimal conditions for CSCs to fulfill their lethal potential. The present review also investigated the main methods involved in local immunosuppression treatment, and highlighted the associated disadvantages. In addition, novel treatment options and targets for the elimination and regulation of CSCs with adaptive and active IT are discussed. Antagonists of TGF-β inhibitors, immune checkpoints and other targeted medication are also summarized. The role of normal hematopoietic stem cells (HSCs) in the mechanisms underlying systemic immune suppression development in cases of GBM is analyzed, and the potential reprogramming of HSCs during their interaction with cancer cells is discussed. Moreover, the present review emphasizes the importance of the aforementioned interactions in the development of immune tolerance and the inactivation of the immune system in neoplastic processes. The possibility of solving the problem of systemic immunosuppression during transplantation of donor HSCs is discussed.

Therapeutic Options for Recurrent Glioblastoma—Efficacy of Talaporfin Sodium Mediated Photodynamic Therapy

Recurrent glioblastoma (GBM) remains one of the most challenging clinical issues, with no standard treatment and effective treatment options. To evaluate the efficacy of talaporfin sodium (TS) mediated photodynamic therapy (PDT) as a new treatment for this condition, we retrospectively analyzed 70 patients who underwent surgery with PDT (PDT group) for recurrent GBM and 38 patients who underwent surgery alone (control group). The median progression-free survival (PFS) in the PDT and control groups after second surgery was 5.7 and 2.2 months, respectively (p = 0.0043). The median overall survival (OS) after the second surgery was 16.0 and 12.8 months, respectively (p = 0.031). Both univariate and multivariate analyses indicated that surgery with PDT and a preoperative Karnofsky Performance Scale were significant independent prognostic factors for PFS and OS. In the PDT group, there was no significant difference regarding PFS and OS between patients whose previous pathology before recurrence was already GBM and those who had malignant transformation to GBM from lower grade glioma. There was also no significant difference in TS accumulation in the tumor between these two groups. According to these results, additional PDT treatment for recurrent GBM could have potential survival benefits and its efficacy is independent of the pre-recurrence pathology.

Immune-checkpoint inhibitors in pituitary malignancies

To date, there are no standardized systemic treatment options for patients with metastatic pituitary carcinoma progressed to chemo and radiation therapy. Immune-checkpoint inhibitors (ICIs) have been successfully assessed in other solid malignancies and could be a concrete hope for these patients. We performed a critical review of the literature aimed to evaluate studies assessing ICIs in pituitary malignancies. We also conducted research about published translational data assessing immune-contexture in these malignancies. Some preliminary reports reported a successful administration of pembrolizumab or the combination between nivolumab and ipilimumab in patients with metastatic ACTH-secreting pituitary carcinomas. Translational data suggest that adenomas secreting growth hormone and ACTH have a suppressed immune-microenvironment, which could be more likely to benefit from ICIs. Immune-checkpoint inhibitors can be an effective treatment in patients with pituitary carcinoma and maybe also recurrent adenoma. Tumors secreting growth hormone and ACTH are more likely to benefit from ICIs due to a different immune-microenvironment.

Surgical Outcomes of Novel Collagen Tile Cesium Brachytherapy for Recurrent Intracranial Tumors at a Tertiary Referral Center

Treatment for recurrent intracranial neoplasms is often difficult and less standardized. Since its approval by the Food & Drug Administration (FDA), GammaTile^TM (GT, GT Medical Technologies, Tempe, AZ), a novel collagen tile cesium brachytherapy, has been investigated for use in this population. This study presents the initial experience with the use of GT for patients with recurrent intracranial neoplasms at a tertiary referral center. A retrospective analysis of all patients with GT implantation from November 2019 to July 2021 was performed. Information regarding demographics, clinical history, imaging data, prior tumor treatment, dosing, surgical complications, and outcomes was collected. Twelve patients were included in this study. Pathologies included gliomas (five patients), meningiomas (five patients), and metastatic tumors (two patients). The median tumor volume treated was 24 cc (IQR: 21.2 - 31.3 cc), and patients had a median of 7.5 tiles implanted (IQR: 5.4 - 10.3). One patient had a delayed epidural hematoma requiring reoperation, which was unrelated to GT implantation. Median follow-up was seven months (IQR: 3 -10), with the longest follow-up time of 20 months. Two patients have had local disease recurrence and three patients have had systemic progression of their disease. Three patients are deceased with survivals of 2.9, 4.8, and 5.8 months. Collagen tile brachytherapy is a safe and viable option for patients with recurrent intracranial tumors. Our data are consistent with early results seen at other institutions. Long-term data with larger patient populations are required to assess efficacy, safety, and indications for the use of this novel technology.

The PI3K Inhibitor XH30 Enhances Response to Temozolomide in Drug-Resistant Glioblastoma via the Noncanonical Hedgehog Signaling Pathway

Glioblastoma multiforme (GBM) is the most common malignant tumor of the central nervous system. Temozolomide (TMZ)-based adjuvant treatment has improved overall survival, but clinical outcomes remain poor; TMZ resistance is one of the main reasons for this. Here, we report a new phosphatidylinositide 3-kinase inhibitor, XH30; this study aimed to assess the antitumor activity of this compound against TMZ-resistant GBM. XH30 inhibited cell proliferation in TMZ-resistant GBM cells (U251/TMZ and T98G) and induced cell cycle arrest in the G1 phase. In an orthotopic mouse model, XH30 suppressed TMZ-resistant tumor growth. XH30 was also shown to enhance TMZ cytotoxicity both in vitro and in vivo. Mechanistically, the synergistic effect of XH30 may be attributed to its repression of the key transcription factor GLI1 via the noncanonical hedgehog signaling pathway. XH30 reversed sonic hedgehog-triggered GLI1 activation and decreased GLI1 activation by insulin-like growth factor 1 via the noncanonical hedgehog signaling pathway. These results indicate that XH30 may represent a novel therapeutic option for TMZ-resistant GBM.

Radiomics, mirnomics, and radiomirRNomics in glioblastoma: defining tumor biology from shadow to light

INTRODUCTION

Glioblastoma is a highly aggressive brain tumor with an extremely poor prognosis. Genetic characterization of this tumor has identified alterations with prognostic and therapeutic impact, and many efforts are being made to improve molecular knowledge on glioblastoma. Invasive procedures, such as tumor biopsy or radical resection, are needed to characterize the tumor.

AREAS COVERED

The role of microRNA in cancer is an expanding field of research as many microRNAs have been shown to correlate with patient prognosis and treatment response. Novel methodologies like radiomics, radiogenomics, and radiomiRNomics are under evaluation to improve the amount of prognostic and predictive biomarkers available.

EXPERT OPINION

The role of radiomics, radiogenomics, and radiomiRNomic for the characterization of glioblastoma will further improve in the coming years.

Distinct MRI pattern of "pseudoresponse" in recurrent glioblastoma multiforme treated with regorafenib: Case report and literature review

Antiangiogenic agents can induce a distinct MRI pattern in glioblastoma, characterized by a decrease in the contrast enhancement on T1-weighted images and a simultaneous hyperintensity on T2-weighted or fluid-attenuated inversion recovery images.

Glioblastoma: Emerging Treatments and Novel Trial Designs

Simple Summary

Nowadays, very few systemic agents have shown clinical activity in patients with glioblastoma, making the research of novel therapeutic approaches a critical issue. Fortunately, the availability of novel compounds is increasing thanks to better biological knowledge of the disease. In this review we want to investigate more promising ongoing clinical trials in both primary and recurrent GBM. Furthermore, a great interest of the present work is focused on novel trial design strategies.

Abstract

Management of glioblastoma is a clinical challenge since very few systemic treatments have shown clinical efficacy in recurrent disease. Thanks to an increased knowledge of the biological and molecular mechanisms related to disease progression and growth, promising novel treatment strategies are emerging. The expanding availability of innovative compounds requires the design of a new generation of clinical trials, testing experimental compounds in a short time and tailoring the sample cohort based on molecular and clinical behaviors. In this review, we focused our attention on the assessment of promising novel treatment approaches, discussing novel trial design and possible future fields of development in this setting.

The clinical and prognostic role of ALK in glioblastoma

BACKGROUND

anaplastic lymphoma kinase (ALK) overexpression and gene alterations have been detected in several malignancies, with prognostic and therapeutic implications. However, few studies investigated the correlation between ALK altered expression and prognosis in patients with glioblastoma (GBM).

METHODS

We performed an evaluation of ALK overexpression and structural/quantitative chromosome alterations through immune-histochemical assay (IHC with D5F3 antibody) and fluorescent in situ hybridization (FISH) in patients with isocitrate dehydrogenase (IDH) wild type (wt) GBM. Assuming an ALK overexpression in 20 % of patients we planned a sample of 44 patients to achieve a probability of 90 % to include from 10 % to 30 % of patients with ALK alterations.

RESULTS

We evaluated 44 patients with IDH wt GBM, treated in our institution and dead due to GBM progression in 2017. ALK overexpression obtained by a composed score (the product of IHC intensity staining and rate of positive cells) was observed in 19 (43 %) patients. FISH analysis showed that 11 patients (25 %) had gene deletion, 2 patients (4.5 %) had monosomy and one patient (2.3 %) presented polysomy. Only one patient (2.3 %) demonstrated ALK rearrangement. There was no statistical difference in median OS between patients with ALK-positive (mOS = 18.9 months) and ALK-negative IHC (mOS = 18.0 months).

CONCLUSION

We identified some rare previously unreported alterations of ALK gene in patients with IDH wt GBM. In these patients, the ALK overexpression does not influences survival.