Near-complete response to low-dose ceritinib in recurrent infantile inflammatory myofibroblastic tumour

Drugging Hijacked Kinase Pathways in Pediatric Oncology: Opportunities and Current Scenario

Childhood cancer is considered rare, corresponding to ~3% of all malignant neoplasms in the human population. The World Health Organization (WHO) reports a universal occurrence of more than 15 cases per 100,000 inhabitants around the globe, and despite improvements in diagnosis, treatment and supportive care, one child dies of cancer every 3 min. Consequently, more efficient, selective and affordable therapeutics are still needed in order to improve outcomes and avoid long-term sequelae. Alterations in kinases' functionality is a trademark of cancer and the concept of exploiting them as drug targets has burgeoned in academia and in the pharmaceutical industry of the 21st century. Consequently, an increasing plethora of inhibitors has emerged. In the present study, the expression patterns of a selected group of kinases (including tyrosine receptors, members of the PI3K/AKT/mTOR and MAPK pathways, coordinators of cell cycle progression, and chromosome segregation) and their correlation with clinical outcomes in pediatric solid tumors were accessed through the R2: Genomics Analysis and Visualization Platform and by a thorough search of published literature. To further illustrate the importance of kinase dysregulation in the pathophysiology of pediatric cancer, we analyzed the vulnerability of different cancer cell lines against their inhibition through the Cancer Dependency Map portal, and performed a search for kinase-targeted compounds with approval and clinical applicability through the CanSAR knowledgebase. Finally, we provide a detailed literature review of a considerable set of small molecules that mitigate kinase activity under experimental testing and clinical trials for the treatment of pediatric tumors, while discuss critical challenges that must be overcome before translation into clinical options, including the absence of compounds designed specifically for childhood tumors which often show differential mutational burdens, intrinsic and acquired resistance, lack of selectivity and adverse effects on a growing organism.

An extremely rare case of malignant jejunal mesenteric inflammatory myofibroblastic tumor in a 61-year-old male patient: A case report and literature review

Introduction

A mesenteric inflammatory myofibroblastic tumor (IMT) is a rare solid tumor of intermediate malignant potential that affects children, adolescents, and young adults predominantly. IMT is mostly encountered in the lung. We report a case of malignant jejunal mesenteric IMT in a 61-year-old male patient who presented with vague abdominal pain and generalized weakness. CT scan revealed a mesenteric mass displacing the attached jejunum. Surgical resection was curative.

Discussion

An extensive literature review was performed to update and further analyze the already available data. A total of 35 cases with mesenteric IMT were reported previously. Only five cases of jejunal mesenteric IMT were reported. Mesenteric IMT demands vast effort to reveal the diagnosis due to its vagueness in the clinical presentation. Mesenteric IMT resembles each other in plenty of pathological and immunohistochemical characteristics.

Conclusion

To the best of our knowledge, this is the first case of malignant jejunal mesenteric IMT in the elderly. Surgical resection was curative.

Histologic characterization of pediatric mesenchymal neoplasms treated with kinase-targeted therapy

AIMS

Recurrent alterations involving receptor tyrosine or cytoplasmic kinase genes have been described in soft tissue neoplasms such as infantile fibrosarcoma (IFS) and inflammatory myofibroblastic tumor (IMT). Recent trials and regulatory approvals for targeted inhibitors against the kinase domains of these oncoproteins have allowed for increased use of targeted therapies. We aimed to characterize the histologic features of pediatric mesenchymal neoplasms with kinase alterations treated with targeted inhibitors.

METHODS AND RESULTS

Eight patients with tyrosine kinase-altered mesenchymal neoplasms with pre- and post-treatment samples were identified. Tumors occurred in 5 females and 3 males with a median age at presentation of 6.5 years. Tumor sites were bone/somatic soft tissue (n=5) and viscera (n=3). Pre-treatment diagnoses were: IMT (n=3), epithelioid inflammatory myofibroblastic sarcoma (n=1), and descriptive diagnoses (n=4) such as "kinase-driven spindle cell tumor". Fusions identified were ETV6::NTRK3 (n=2), TPM3::NTRK1, SEPT7::BRAF, TFG::ROS1, KLC1::ALK, RANBP2::ALK, and MAP4::RAF1. Patients were treated with larotrectinib (n=3), ALK or ALK/ROS1 inhibitors (n=3), and MEK inhibitors (n=2). Post-treatment tumors exhibited a striking decrease in cellularity (7/8) and the presence of collagenous stroma (7/8) with extensive glassy hyalinization (5/8). In two cases, abundant coarse or psammomatous calcifications were seen and in one case prominent perivascular hyalinization was noted. Residual viable tumor was seen in 3/8 cases (<5% in one case, and >75% in 2/8 cases).

CONCLUSIONS

Mesenchymal neoplasms with tyrosine kinase alterations treated with targeted inhibitors show pathologic response, which includes decreased cellularity and stromal hyalinization. The presence of these features may be helpful in assessing tumor response after targeted therapy.

Molecular Targets for Novel Therapeutics in Pediatric Fusion-Positive Non-CNS Solid Tumors

Chromosomal fusions encoding novel molecular drivers have been identified in several solid tumors, and in recent years the identification of such pathogenetic events in tumor specimens has become clinically actionable. Pediatric sarcomas and other rare tumors that occur in children as well as adults are a group of heterogeneous tumors often with driver gene fusions for which some therapeutics have already been developed and approved, and others where there is opportunity for progress and innovation to impact on patient outcomes. We review the chromosomal rearrangements that represent oncogenic events in pediatric solid tumors outside of the central nervous system (CNS), such as Ewing Sarcoma, Rhabdomyosarcoma, Fibrolamellar Hepatocellular Carcinoma, and Renal Cell Carcinoma, among others. Various therapeutics such as CDK4/6, FGFR, ALK, VEGF, EGFR, PDGFR, NTRK, PARP, mTOR, BRAF, IGF1R, HDAC inhibitors are being explored among other novel therapeutic strategies such as ONC201/TIC10.