Tailored therapy for recurrent glioblastoma: report of a personalized molecular approach

Cerebellopontine angle pilocytic astrocytoma in adults: A systematic review

Background

In adults, the cerebellopontine angle (CPA) pilocytic astrocytoma (PA) is very rare. This tumor has radiological features similar to those of a vestibular schwannoma in the few cases reported in the literature.

Methods

In this study, we conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol and scrutinized all original studies pertaining to pontocerebellar angle PA in adult patients. We conducted an analysis of the clinical, radiological, and molecular components of all eligible articles. We have also reported a case involving a 67-year-old male individual in whom the PA exhibited radiological characteristics similar to an epidermoid cyst.

Results

After the screening phase, we found four cases of PA of the pontocerebellar angle. Three cases were identified that resembled vestibular schwannoma; however, in our case, the tumor resembled an epidermoid cyst. These uncommon tumors exhibit distinctive histological patterns and molecular characteristics (adenosine triphosphate dependent helicase (ATP- dependent helicase)+, Isocitrate dehydrogenase 1-), rendering them a potential differential diagnosis for glioblastoma (GBM).

Conclusion

The CPA PA has rarely been found in adult patients and should be considered in the differential diagnosis of vestibular schwannoma and epidermoid cysts. In these rare cases, the histological characteristics of PA are significant for the differential diagnosis of GBM.

Recurrent Glioblastoma Treatment: State of the Art and Future Perspectives in the Precision Medicine Era

Current treatment guidelines for the management of recurrent glioblastoma (rGBM) are far from definitive, and the prognosis remains dismal. Despite recent advancements in the pharmacological and surgical fields, numerous doubts persist concerning the optimal strategy that clinicians should adopt for patients who fail the first lines of treatment and present signs of progressive disease. With most recurrences being located within the margins of the previously resected lesion, a comprehensive molecular and genetic profiling of rGBM revealed substantial differences compared with newly diagnosed disease. In the present comprehensive review, we sought to examine the current treatment guidelines and the new perspectives that polarize the field of neuro-oncology, strictly focusing on progressive disease. For this purpose, updated PRISMA guidelines were followed to search for pivotal studies and clinical trials published in the last five years. A total of 125 articles discussing locoregional management, radiotherapy, chemotherapy, and immunotherapy strategies were included in our analysis, and salient findings were critically summarized. In addition, an in-depth description of the molecular profile of rGBM and its distinctive characteristics is provided. Finally, we integrate the above-mentioned evidence with the current guidelines published by international societies, including AANS/CNS, EANO, AIOM, and NCCN.

Molecular Analysis in a Glioblastoma Cohort-Results of a Prospective Analysis

The prognostic role of epidermal growth factor receptor variant III (EGFRvIII), a constitutively activated oncogenic receptor, in glioblastoma is controversial. We performed a prospective study enrolling 355 patients operated on for de novo glioblastoma at a large academic center. The molecular profile, including EGFRvIII status, MGMT promoter methylation, and VEGF expression, was assessed. Standard parameters (age, clinical status and extent of surgical resection) were confirmed to hold prognostic value. MGMT promoter methylation portended a slightly improved survival. In the whole series, confirming previous results, EGFRvIII was not associated with worsened prognosis. Interestingly, female sex was associated with a better outcome. Such findings are of interest for the design of future trials.

Glioblastoma multiforme (GBM): An overview of current therapies and mechanisms of resistance

Glioblastoma multiforme (GBM) is a WHO grade IV glioma and the most common malignant, primary brain tumor with a 5-year survival of 7.2%. Its highly infiltrative nature, genetic heterogeneity, and protection by the blood brain barrier (BBB) have posed great treatment challenges. The standard treatment for GBMs is surgical resection followed by chemoradiotherapy. The robust DNA repair and self-renewing capabilities of glioblastoma cells and glioma initiating cells (GICs), respectively, promote resistance against all current treatment modalities. Thus, durable GBM management will require the invention of innovative treatment strategies. In this review, we will describe biological and molecular targets for GBM therapy, the current status of pharmacologic therapy, prominent mechanisms of resistance, and new treatment approaches. To date, medical imaging is primarily used to determine the location, size and macroscopic morphology of GBM before, during, and after therapy. In the future, molecular and cellular imaging approaches will more dynamically monitor the expression of molecular targets and/or immune responses in the tumor, thereby enabling more immediate adaptation of tumor-tailored, targeted therapies.