Bevacizumab is an active agent for recurrent high-grade glioma, but do we need randomized controlled trials?

Prognostic factors influencing survival following re-resection for isocitrate dehydrogenase (IDH) -wildtype glioblastoma multiforme - Data from a national neuro-oncology registry

The role of surgical resection in recurrent Glioblastoma Multiforme (GBM) remains unclear. We aimed to investigate survival outcomes and associated prognostic factors in patients undergoing surgical re-resection for recurrent IDH-wildtype GBM in a national neuro-oncology center. We evaluated all patients who underwent re-resection for recurrent GBM following adjuvant treatment between 2015 and 2018. 32 patients were eligible for inclusion. 19 (59%) were male,median age at re-resection was 53. Median time from initial surgery to re-resection was 13.5 months. Median overall survival (OS) was 28.6 months from initial surgery and 9.5 months from re-resection. MGMT methylation was significantly associated with improved OS from initial surgery, 40 months versus 19.1 months, (p = 0.004), and from re-resection, 9.47 months versus 6.93 months, (p = 0.028). A late re-resection was associated with improved OS compared to an early re-resection, 44.1 months versus 15.7 months, (p = 0.002). There was a trend for improved outcomes in younger patients, median OS from initial surgery 44.1 months for <53 years compared to 21.7 months for patients ≥53, (p = 0.099). Higher Karnofsky Performance Status (KPS) at re-resection was associated with improved median OS, 9.5 months versus 4.1 months for KPS ≥70 and <70 respectively, (p = 0.013). Furthermore, there was a trend for improved OS with greater extent of re-resection, however this did not reach statistical significance, possibly due to small sample size. Re-resection for recurrent GBM was associated with improved OS in those with good performance status and could be considered in carefully selected cases.

Role of glioblastoma stem cells in cancer therapeutic resistance: a perspective on antineoplastic agents from natural sources and chemical derivatives

Glioblastoma (GBM) is the highest-grade form of glioma, as well as one of the most aggressive types of cancer, exhibiting rapid cellular growth and highly invasive behavior. Despite significant advances in diagnosis and therapy in recent decades, the outcomes for high-grade gliomas (WHO grades III-IV) remain unfavorable, with a median overall survival time of 15–18 months. The concept of cancer stem cells (CSCs) has emerged and provided new insight into GBM resistance and management. CSCs can self-renew and initiate tumor growth and are also responsible for tumor cell heterogeneity and the induction of systemic immunosuppression. The idea that GBM resistance could be dependent on innate differences in the sensitivity of clonogenic glial stem cells (GSCs) to chemotherapeutic drugs/radiation prompted the scientific community to rethink the understanding of GBM growth and therapies directed at eliminating these cells or modulating their stemness. This review aims to describe major intrinsic and extrinsic mechanisms that mediate chemoradioresistant GSCs and therapies based on antineoplastic agents from natural sources, derivatives, and synthetics used alone or in synergistic combination with conventional treatment. We will also address ongoing clinical trials focused on these promising targets. Although the development of effective therapy for GBM remains a major challenge in molecular oncology, GSC knowledge can offer new directions for a promising future.

Zirconium-89 labeled antibodies: a new tool for molecular imaging in cancer patients

Antibody based positron emission tomography (immuno-PET) imaging is of increasing importance to visualize and characterize tumor lesions. Additionally, it can be used to identify patients who may benefit from a particular therapy and monitor the therapy outcome. In recent years the field is focused on ⁸⁹Zr, a radiometal with near ideal physical and chemical properties for immuno-PET. In this review we will discuss the production of  ⁸⁹Zr, the bioconjugation strategies, and applications in (pre-)clinical studies of  ⁸⁹Zr-based immuno-PET in oncology. To date, ⁸⁹Zr-based PET imaging has been investigated in a wide variety of cancer-related targets. Moreover, clinical studies have shown the feasibility for ⁸⁹Zr-based immuno-PET to predict and monitor treatment, which could be used to tailor treatment for the individual patient. Further research should be directed towards the development of standardized and robust conjugation methods and improved chelators to minimize the amount of released Zr⁴⁺ from the antibodies. Additionally, further validation of the imaging method is required. The ongoing development of new ⁸⁹Zr-labeled antibodies directed against novel tumor targets is expected to expand applications of  ⁸⁹Zr-labeled immuno-PET to a valuable method in the medical imaging.

Pediatric high grade glioma: a review and update on tumor clinical characteristics and biology

High grade gliomas (HGG) are one of the most common central nervous system (CNS) tumors encountered in adults, but they only represent approximately 8–12% of all pediatric CNS tumors. Historically, pediatric HGG were thought to be similar to adult HGG since they appear histologically identical; however, molecular, genetic, and biologic data reveal that they are distinct. Similar to adults, pediatric HGG are very aggressive and malignant lesions with few patients achieving long-term survival despite a variety of therapies. Initial treatment strategies typically consist of a gross total resection (GTR) when feasible followed by focal radiotherapy combined with chemotherapy. Over the last few decades, a wealth of data has emerged from basic science and pre-clinical animal models helping to better define the common biologic, genetic, and molecular make-up of these tumors. These data have not only provided a better understanding of tumor biology, but they have also provided new areas of research targeting molecular and genetic pathways with the potential for novel treatment strategies and improved patient outcomes. Here we provide a review of pediatric non-brainstem HGG, including epidemiology, presentation, histology, imaging characteristics, treatments, survival outcomes, and an overview of both basic and translational research. An understanding of all relevant pre-clinical tumor models, including their strengths and pitfalls is essential in realizing improved patient outcomes in this population.