Mimicking Retinoblastoma Treatment With Repeated Topotecan or Melphalan Develops Cross-Resistance to Classic Agents But Not to Repurposed Drugs.

Purpose: Refractory or recurrent retinoblastoma results from acquired chemoresistance and the management of these eyes often requires surgical removal. Our objective was to develop retinoblastoma models resistant to chemotherapy by exposing cancer cells to repeated chemotherapy mimicking the clinical scenario. These newly resistant cells were used to evaluate potential novel therapies.

The TeLeo Program: Tele-education in pediatric oncology as a tool to support training programs in Latin America.

The TeLeo Program offers a free-access 2-year online learning program to support fellowship programs in pediatric oncology, enhance networking opportunities, and facilitate the exchange of context-specific, educational content within the pediatric oncology community in training in Latin America. In its first edition beginning in 2021, 185 fellows from 40 centers in 12 Latin American countries were enrolled. Additional courses for other healthcare professionals related to oncology in the region were produced to further support the program.

International Society of Paediatric Oncology (SIOP) Global Mapping Program: Analysis of healthcare centers in countries of the Latin American Society of Pediatric Oncology (SLAOP).

Background: The International Society of Paediatric Oncology Society Global Mapping Program aims to describe the local pediatric oncology capacities. Here, we report the data from Latin America.

Methods: A 10-question survey was distributed among chairs of pediatric oncology services.

Establishment and Comprehensive Characterization of a Novel Preclinical Platform of Metastatic Retinoblastoma for Therapeutic Developments.

Purpose: Although there have been improvements in the management of metastatic retinoblastoma, most patients do not survive, and all patients suffer from multiple short- and long-term treatment toxicities. Reliable and informative models to assist clinicians are needed. Thus we developed and comprehensively characterized a novel preclinical platform of primary cell cultures and xenograft models of metastatic retinoblastoma to provide insights into the molecular biology underlying metastases and to perform drug screening for the identification of hit candidates with the highest potential for clinical translation.

Immunohistochemical expression of TFF1 is a marker of poor prognosis in retinoblastoma.

Introduction: The risk of relapse in retinoblastoma is currently determined by the presence of high-risk histopathologic factors in the enucleated eye. However, the probability of developing metastatic disease is heterogeneous among these patients. Evaluating a biological marker to identify high-risk patients could be useful in clinical setting.

Pharmacokinetics of Orbital Topotecan After Ophthalmic Artery Chemosurgery and Intravenous Infusion in the Swine Model.

Purpose: Surgery, multiagent systemic chemotherapy, and radiation are used for patients with orbital retinoblastoma but are associated with unacceptable short- and long-term toxicity (including death). We studied orbital and systemic exposure of topotecan in the swine model after ophthalmic artery chemosurgery (OAC) and intravenous (IV) delivery.

Methods: Landrace pigs (n = 3) underwent 30-minute OAC of topotecan (4 mg), and samples were serially obtained from the femoral artery and from a microdialysis probe inserted into the lateral rectus muscle sheath of the infused eye as a surrogate of the orbital irrigation.

How we approach conservative treatment of retinoblastoma in South America in the era of local ocular treatments: A consensus of the Grupo America Latina de Oncologia Pediatrica (GALOP).

Local therapies are increasingly used for ocular preservation in retinoblastoma. In middle-income countries, these techniques pose specific challenges mostly related to more advanced disease at diagnosis. The Grupo de America Latina de Oncología Pediátrica (GALOP) developed a consensus document for the management of conservative therapy for retinoblastoma.

A Systematic Review of High-Dose Methotrexate for Adults with Primary Central Nervous System Lymphoma.

Primary central nervous system lymphoma (PCNSL) is a highly aggressive non-Hodgkin lymphoma that is confined within the CNS. Due to its ability to cross the blood-brain barrier, high-dose methotrexate (HDMTX) is the backbone for induction chemotherapy. This systematic review was conducted to observe outcomes among different HDMTX doses (low, <3 g/m; intermediate, 3-4.

Impact of COVID-19 in pediatric oncology care in Latin America during the first year of the pandemic.

Background: The ongoing coronavirus 2019 disease (COVID-19) pandemic strained medical systems worldwide. We report on the impact on pediatric oncology care in Latin American (LATAM) during its first year.

Method: Four cross-sectional surveys were electronically distributed among pediatric onco-hematologists in April/June/October 2020, and April/2021 through the Latin American Society of Pediatric Oncology (SLAOP) email list and St Jude Global regional partners.

Subsequent malignant neoplasms in the pediatric age in retinoblastoma survivors in Argentina.

Background: Retinoblastoma survivors in low- and middle-income countries are exposed to high-intensity treatments that potentially place them at higher risk of early subsequent malignant neoplasms (SMNs).

Methods: We followed 714 (403 [56.4%] nonhereditary and 311 [43.

[Targeted therapies with BRAF inhibitors for pediatric low- and high-grade gliomas with BRAFv600e mutation. Prof. Dr. Juan P. Garrahan Hospital experience].

The BRAFV600E point mutation plays a key role in the tumorigenesis of many gliomas. Inhibiting its product is part of the innovative therapies emerging in recent years. Knowing the role of these treatments is essential.

Craniospinal irradiation as part of re-irradiation for children with recurrent medulloblastoma.

Background: Many studies have demonstrated in the last years that once medulloblastoma has recurred, the probability of regaining tumor control is poor despite salvage therapy. Although re-irradiation has an emerging role in other relapsed brain tumors, there is a lack of strong data on re-irradiation for medulloblastoma.

Methods: This is a retrospective cohort study of patients aged 18 years or under, treated at least by a second course of external beam for recurrence medulloblastoma at Garrahan Hospital between 2009 and 2020.

Intracranial germ cells tumour: a single institution experience in Argentina.

Background: Intracranial germ cell tumor (iGCT) represents a rare and heterogeneous group, with variable incidence and diverse treatment strategies. Although multiagent chemotherapy with reduced radiotherapy strategy has been applied by several cooperative groups in North America and Western Europe, there is a paucity of data to understand if this combined regimen is suitable in low-middle income countries (LMIC).

Methods: We evaluate the outcome in a cohort of iGCT treated by SIOP-CNS-GCT-96 strategy at hospital J.

Recurrent Somatic Chromosomal Abnormalities in Relapsed Extraocular Retinoblastoma.

Most reports about copy number alterations (CNA) in retinoblastoma relate to patients with intraocular disease and features of children with extraocular relapse remain unknown, so we aimed to describe the CNA in this population. We evaluated 23 patients and 27 specimens from 4 centers. Seventeen cases had extraocular relapse after initial enucleation and six cases after an initial preservation attempt.

A decision process for drug discovery in retinoblastoma.

Intraocular retinoblastoma treatment has changed radically over the last decade, leading to a notable improvement in ocular survival. However, eyes that relapse remain difficult to treat, as few alternative active drugs are available. More challenging is the scenario of central nervous system (CNS) metastasis, in which almost no advancements have been made.

Clinical, Genomic, and Pharmacological Study of -Amplified Wild-Type Metastatic Retinoblastoma.

An uncommon subgroup of unilateral retinoblastomas with highly aggressive histological features, lacking aberrations in gene with high-level amplification of (ampl+/+) has only been described as intra-ocular cases treated with initial enucleation. Here, we present a comprehensive clinical, genomic, and pharmacological analysis of two cases of ampl+/+ with orbital and cervical lymph node involvement, but no central nervous system spread, rapidly progressing to fatal disease due to chemoresistance. Both patients showed in common high amplification and chromosome 16q and 17p loss.

Treatment response of CNS high-grade neuroepithelial tumors with MN1 alteration.

Central nervous system high-grade neuroepithelial tumor with MN1 alteration (CNS HGNET-MN1) is a rare recently described entity. Fourteen CNS HGNET-MN1 patients were identified using genome-wide methylation arrays/RT-PCR across seven institutions. All patients had surgery (gross total resection: 10; subtotal resection: four) as initial management followed by observation alone in three patients, followed by radiotherapy in eight patients (focal: five; craniospinal: two; CyberKnife: one) and systemic chemotherapy in three patients.

Bridging the treatment gap in infant medulloblastoma: molecularly informed outcomes of a globally feasible regimen.

Background: Infant medulloblastoma represents an enormous challenge in neuro-oncology, due to their simultaneous high-risk of recurrence and high risk of severe neurodevelopmental sequelae with craniospinal irradiation. Currently infant medulloblastoma are treated with intensified protocols, either comprising intraventricular methotrexate or autologous transplant, both of which carry significant morbidity and are not feasible in the majority of the world. We sought to evaluate the molecular predictors of outcome in a cohort of infants homogeneously treated with induction chemotherapy, focal radiation and maintenance chemotherapy.

Genomic and Transcriptomic Tumor Heterogeneity in Bilateral Retinoblastoma.

Importance: Comprehensive understanding of the genomic and gene-expression differences between retinoblastoma tumors from patients with bilateral disease may help to characterize risk and optimize treatment according to individual tumor characteristics.

Objective: To compare the genomic features between each eye and a specimen from an orbital relapse in patients with bilateral retinoblastoma.

Design, Setting, And Participants: In this case, 2 patients with retinoblastoma underwent upfront bilateral enucleation.

Tridimensional Retinoblastoma Cultures as Vitreous Seeds Models for Live-Cell Imaging of Chemotherapy Penetration.

A preclinical model could aid in understanding retinoblastoma vitreous seeds behavior, drug penetration, and response to chemotherapy to optimize patient treatment. Our aim was to develop a tridimensional in vitro model of retinoblastoma vitreous seeds to assess chemotherapy penetration by means of live-cell imaging. Cell cultures from patients with retinoblastoma who underwent upfront enucleation were established and thoroughly characterized for authentication of human tumor origin.

Minimally disseminated disease and outcome in overt orbital retinoblastoma.

In this retrospective study of patients with overt orbital retinoblastoma, we evaluated minimally disseminated disease (MDD) in bone marrow and cerebrospinal fluid (CSF) using CRX and/or GD2 synthase as markers. Ten patients were evaluated-five (50%) at diagnosis and five upon relapse. MDD was detected in four cases (one in the bone marrow, two in the CSF, and in one case in both sites).

Minimal disseminated disease evaluation and outcome in trilateral retinoblastoma.

Unlabelled: Trilateral retinoblastoma (TRb) presents a management challenge, since intracranial tumours are seldom times resectable and quickly disseminate. However, there are no risk factors to predict the final outcome in each patient.

Objective: To evaluate minimal disseminated disease (MDD) in the bone marrow (BM) and the cerebrospinal fluid (CSF) at diagnosis and during follow-up and reviewing its potential impact in the outcome of patients with TRb.