Genomic characterization of a PPP1CB-ALK fusion with fusion gene amplification in a congenital glioblastoma

Exploring a distinct FGFR2::DLG5 rearrangement in a low-grade neuroepithelial tumor: A case report and mini-review of protein fusions in brain tumors

We report the novel clinical presentation of a primary brain neoplasm in a 30-year-old man with a mass-like area in the anteromedial temporal lobe. Histopathological analysis revealed a low-grade neuroepithelial tumor with cytologically abnormal neurons and atypical glial cells within the cerebral cortex. Molecular analysis showed a previously undescribed FGFR2::DLG5 rearrangement. We discuss the clinical significance and molecular implications of this fusion event, shedding light on its potential impact on tumor development and patient prognosis. Additionally, an extensive review places the finding in this case in the context of protein fusions in brain tumors in general and highlights their diverse manifestations, underlying molecular mechanisms, and therapeutic implications.

Case report: ATIC-ALK fusion in infant-type hemispheric glioma and response to lorlatinib

Introduction

Infant type hemispheric gliomas are a rare tumor with unique molecular characteristics. In many cases these harbor mutations in receptor tyrosine kinase pathways and respond to targeted therapy. Here we describe the case of an infant with this type of tumor with a novel ATIC-ALK fusion that has responded dramatically to the ALK inhibitor lorlatinib, despite being refractory to standard chemotherapy.

Case description

The infant was initially treated with standard chemotherapy and found to have an ATIC-ALK fusion. When surveillance imaging revealed progressive disease, the patient was switched to the ALK-inhibitor lorlatinib at 47 mg/m²/day. The patient demonstrated a significant clinical and radiographic response to the ALK inhibitor lorlatinib after just 3 months of treatment and a near complete response by 6 months of therapy.

Conclusion

The ALK inhibitor lorlatinib is an effective targeted therapy in infant type hemispheric glioma patients harboring ATIC-ALK fusion.

Hallmarks of Anaplastic Lymphoma Kinase Inhibitors with Its Quick Emergence of Drug Resistance

Anaplastic lymphoma kinase (ALK) is one of the most popular targets for anticancer therapies. In the past decade, the use of anaplastic lymphoma tyrosine kinase inhibitors (ALK-TKIs), including crizotinib and ceritinib, has been a reliable and standard options for patients with lung cancer, particularly for patients with nonsmall cell lung carcinoma. ALK-targeted therapies initially benefit the patients, yet, resistance eventually occurs. Therefore, resistance mechanisms of ALK-TKIs and the solutions have become a formidable challenge in the development of ALK inhibitors. In this review, based on the knowledge of reported ALK inhibitors, we illustrated the crystal structures of ALK, summarized the resistance mechanisms of ALK-targeted drugs, and proposed potential therapeutic strategies to prevent or overcome the resistance.

Gliomas in children and adolescents: investigation of molecular alterations with a potential prognostic and therapeutic impact

PURPOSE

Gliomas represent the most frequent central nervous system (CNS) tumors in children and adolescents. However, therapeutic strategies for these patients, based on tumor molecular profile, are still limited compared to the wide range of treatment options for the adult population. We investigated molecular alterations, with a potential prognostic marker and therapeutic target in gliomas of childhood and adolescence using the next-generation sequencing (NGS) strategy.

METHODS

We selected 95 samples with initial diagnosis of glioma from patients treated at Pediatric Oncology Institute-GRAACC/UNIFESP. All samples were categorized according to the 2021 World Health Organization Classification of Tumors of the CNS, which included 39 low-grade gliomas (LGGs) and 56 high-grade gliomas (HGGs). Four HGG samples were classified as congenital glioblastoma (cGBM). NGS was performed to identify somatic genetic variants in tumor samples using the Oncomine Childhood Cancer Research Assay^® (OCCRA^®) panel, from Thermo Fisher Scientific^®.

RESULTS

Genetic variants were identified in 76 of 95 (80%) tumors. In HGGs, the most common molecular alteration detected was H3F3A c.83A > T variant (H3.3 K27M) and co-occurring mutations in ATRX, TP53, PDGFRA, MET, and MYC genes were also frequently observed. One HGG sample was reclassified as supratentorial ependymoma ZFTA-fusion positive after NGS was performed. In LGGs, four KIAA1549-BRAF fusion transcripts were detected and this alteration was the most recurrent genetic event and favorable prognostic factor identified. Additionally, genetic variants in ALK and NTRK genes, which provide potential targets for therapy with Food and Drug Administration-approved drugs, were identified in two different cases of cGBM that were classified as infant-type hemispheric glioma, a newly recognized subgroup of pediatric HGG.

CONCLUSION

Molecular profiling by the OCCRA^® panel comprehensively addressed the most relevant genetic variants in gliomas of childhood and adolescence, as these tumors have specific patterns of molecular alterations, outcomes, and effectiveness to therapies.