Search

Previous studies have shown that children and adolescents with COVID-19 generally have mild disease. Children and adolescents with cancer, however, can have severe disease when infected with respiratory viruses. In this study, we aimed to understand the clinical course and outcomes of SARS-CoV-2 infection in children and adolescents with cancer.We did a cohort study with data from 131 institutions in 45 countries. We created the Global Registry of COVID-19 in Childhood Cancer to capture de-identified data pertaining to laboratory-confirmed SARS-CoV-2 infections in children and adolescents (19 years) with cancer or having received a haematopoietic stem-cell transplantation. There were no centre-specific exclusion criteria. The registry was disseminated through professional networks through email and conferences and health-care providers were invited to submit all qualifying cases. Data for demographics, oncological diagnosis, clinical course, and cancer therapy details were collected. Primary outcomes were disease severity and modification to cancer-directed therapy. The registry remains open to data collection.Of 1520 submitted episodes, 1500 patients were included in the study between April 15, 2020, and Feb 1, 2021. 1319 patients had complete 30-day follow-up. 259 (19·9%) of 1301 patients had a severe or critical infection, and 50 (3·8%) of 1319 died with the cause attributed to COVID-19 infection. Modifications to cancer-directed therapy occurred in 609 (55·8%) of 1092 patients receiving active oncological treatment. Multivariable analysis revealed several factors associated with severe or critical illness, including World Bank low-income or lower-middle-income (odds ratio [OR] 5·8 [95% CI 3·8-8·8]; p0·0001) and upper-middle-income (1·6 [1·2-2·2]; p=0·0024) country status; age 15-18 years (1·6 [1·1-2·2]; p=0·013); absolute lymphocyte count of 300 or less cells per mmIn this global cohort of children and adolescents with cancer and COVID-19, severe and critical illness occurred in one fifth of patients and deaths occurred in a higher proportion than is reported in the literature in the general paediatric population. Additionally, we found that variables associated with treatment modification were not the same as those associated with greater disease severity. These data could inform clinical practice guidelines and raise awareness globally that children and adolescents with cancer are at high-risk of developing severe COVID-19 illness.American Lebanese Syrian Associated Charities and the National Cancer Institute.

PURPOSE Treatment abandonment because of enucleation refusal is a limitation of improving outcomes for children with retinoblastoma in countries with limited resources. Furthermore, many children present with buphthalmos and a high risk of globe rupture during enucleation. To address these unique circumstances, the AHOPCA II protocol introduced neoadjuvant chemotherapy with delayed enucleation. PATIENTS AND METHODS Patients with advanced unilateral intraocular disease (International Retinoblastoma Staging System [IRSS] stage I) were considered for upfront enucleation. Those with diffuse invasion of the choroid, postlaminar optic nerve, and/or anterior chamber invasion received six cycles of adjuvant chemotherapy (vincristine, carboplatin, and etoposide). Patients with buphthalmos and those with a perceived risk for enucleation refusal and/or abandonment were given two to three cycles of chemotherapy before scheduled enucleation followed by adjuvant chemotherapy to complete six cycles, regardless of pathology. RESULTS A total of 161 patients had unilateral IRSS stage I disease; 102 underwent upfront enucleation, and 59 had delayed enucleation. The estimated 5-year abandonment-sensitive event-free and overall survival rates for the group were 0.81 ± 0.03 and 0.86 ± 0.03, respectively. The 5-year estimated abandonment-sensitive event-free survival rates for patients undergoing upfront and delayed enucleation were 0.89 ± 0.03 and 0.68 ± 0.06, respectively ( P = .001). Compared with AHOPCA I, abandonment for patients with IRSS stage I retinoblastoma decreased from 16% to 4%. CONCLUSION AHOPCA describes the results of advanced intraocular retinoblastoma treated with neoadjuvant chemotherapy. In eyes with buphthalmos and patients with risk of abandonment, neoadjuvant chemotherapy can be effective when followed by enucleation and adjuvant chemotherapy. Our study suggests that this approach can save patients with buphthalmos from ocular rupture and might reduce refusal of enucleation and abandonment.

The COVID-19 pandemic poses an unprecedented health crisis in all socio-economic regions across the globe. While the pandemic has had a profound impact on access to and delivery of health care by all services, it has been particularly disruptive for the care of patients with life-threatening noncommunicable diseases (NCDs) such as the treatment of children and young people with cancer. The reduction in child mortality from preventable causes over the last 50 years has seen childhood cancer emerge as a major unmet health care need. Whilst survival rates of 85% have been achieved in high income countries, this has not yet been translated into similar outcomes for children with cancer in resource-limited settings where survival averages 30%. Launched in 2018, by the World Health Organization (WHO), the Global Initiative for Childhood Cancer (GICC) is a pivotal effort by the international community to achieve at least 60% survival for children with cancer by 2030. The WHO GICC is already making an impact in many countries but the disruption of cancer care during the COVID-19 pandemic threatens to set back this global effort to improve the outcome for children with cancer, wherever they may live. As representatives of the global community committed to fostering the goals of the GICC, we applaud the WHO response to the COVID-19 pandemic, in particular we support the WHO's call to ensure the needs of patients with life threatening NCDs including cancer are not compromised during the pandemic. Here, as collaborative partners in the GICC, we highlight specific areas of focus that need to be addressed to ensure the immediate care of children and adolescents with cancer is not disrupted during the pandemic; and measures to sustain the development of cancer care so the long-term goals of the GICC are not lost during this global health crisis. Fil: Pritchard Jones, Kathy. University College London; Estados Unidos Fil: de Abib, Simone C.V.. International Society Of Paediatric Surgical Oncology; Surinam. Universidade Federal de Sao Paulo; Brasil Fil: Esiashvili, Natia. University of Emory; Estados Unidos Fil: Kaspers, Gertjan J.L.. Princess Máxima Center for Pediatric Oncology; Países Bajos Fil: Rosser, Jon. No especifíca; Fil: van Doorninck, John A.. Rocky Mountain Hospital for Children; Estados Unidos Fil: Braganca, João M.L.. No especifíca; Fil: Hoffman, Ruth I.. No especifíca; Fil: Rodriguez Galindo, Carlos. St Jude Children’s Research Hospital; Estados Unidos Fil: Adams, Cary. Union for International Cancer Control; Suiza Fil: Connor, Stephen R.. Worldwide Hospice Palliative Care Alliance; Estados Unidos Fil: Abdelhafeez, Abdelhafeez H.. International Society of Paediatric Surgical Oncology; Suiza. St. Jude Children’s Research Hospital; Estados Unidos Fil: Bouffet, Eric. University Of Toronto. Hospital For Sick Children; Canadá. International Society of Paediatric Surgical Oncology; Suiza Fil: Howard, Scott C.. International Society of Paediatric Surgical Oncology; Suiza. University of Tennessee; Estados Unidos Fil: Challinor, Julia M.. International Society of Paediatric Surgical Oncology; Suiza. University of California; Estados Unidos Fil: Hessissen, Laila. Children Hospital of Rabat; Marruecos. International Society of Paediatric Surgical Oncology; Suiza Fil: Dalvi, Rashmi B.. Bombay Hospital Institute of Medical Sciences; India. International Society of Paediatric Surgical Oncology; Suiza Fil: Kearns, Pamela. International Society of Paediatric Surgical Oncology; Suiza Fil: Chantada, Guillermo Luis. International Society of Paediatric Surgical Oncology; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Frazier, Lindsay A.. International Society of Paediatric Surgical Oncology; Suiza. Dana-Farber Cancer Institute; Estados Unidos Fil: Sullivan, Michael J.. University of Melbourne; Australia. International Society of Paediatric Surgical Oncology; Suiza Fil: Schulte, Fiona S.M.. University of Calgary; Canadá. International Society of Paediatric Surgical Oncology; Suiza Fil: Morrissey, Lisa K.. Boston Children’s Hospital; Estados Unidos. International Society of Paediatric Surgical Oncology; Suiza Fil: Kozhaeva, Olga. European Society for Paediatric Oncology; Bélgica Fil: Luna Fineman, Sandra. Children’s Hospital Colorado; Estados Unidos. International Society of Paediatric Oncology; Suiza Fil: Khan, Muhammad S.. Tawam Hospital; Emiratos Arabes Unidos

Although previous studies have suggested that the complications and mortality rate related to COVID-19 are substantially lower in the paediatric population,1 it is reasonable to consider that children with underlying conditions such as cancer will be at increased risk of severe disease... Fil: Vasquez, Liliana. Universidad de San Martín de Porres; Perú. Organización Panamericana de la Salud; Perú Fil: Sampor, Claudia. Fundacion Hospital de Pediatria Professor Dr. Juan P. Garrahan; Argentina Fil: Villanueva, Gabriela. Fundacion Hospital de Pediatria Professor Dr. Juan P. Garrahan; Argentina Fil: Maradiegue, Essy. Instituto Nacional de Enfermedades Neoplasicas; Perú Fil: Garcia Lombardi, Mercedes. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina Fil: Gomez García, Wendy. Hospital Infantil Dr. Robert Reid Cabral; República Dominicana Fil: Moreno, Florencia. Ministerio de Salud. Instituto Nacional del Cáncer; Argentina Fil: Diaz, Rosdali. Instituto Nacional de Enfermedades Neoplasicas; Perú Fil: Cappellano, Andrea M.. Universidade Federal de Sao Paulo; Brasil Fil: Portilla, Carlos Andres. Universidad del Valle; Colombia Fil: Salas, Beatriz. Hospital del Niño Manuel Ascencio Villarroel; Bolivia Fil: Nava, Evelinda. Hospital de Niños Jesus Garcia Coello; Venezuela Fil: Brizuela, Silvia. Instituto de Previsión Social ; Paraguay Fil: Jimenez, Soledad. Hospital Solca Núcleo de Loja; Ecuador Fil: Espinoza, Ximena. Hospital de Niños Dr. Roberto del Río; Chile Fil: Gassant, Pascale Yola. Hôpital Saint-Damien; Haití Fil: Quintero, Karina. Children's Hospital Dr Jose Renan Esquivel; Panamá Fil: Fuentes Alabi, Soad. Hospital Nacional de Niños Benjamin Bloom; El Salvador Fil: Velasquez, Thelma. No especifíca; Fil: Fu, Ligia. Hospital Escuela de Tegucigalpa; Honduras Fil: Gamboa, Yessika. National Children's Hospital; Costa Rica Fil: Quintana, Juan. Clinica Las Condes; Chile Fil: Castiglioni, Mariela. Hospital Pereira Rossell; Uruguay Fil: Nuñez, Cesar. Children's Cancer Hospital; Estados Unidos Fil: Moreno, Arturo. Hospital Universitario de Puebla; México Fil: Luna Fineman, Sandra. State University of Colorado at Boulder; Estados Unidos Fil: Luciani, Silvana. Pan American Health Organization; Estados Unidos Fil: Chantada, Guillermo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Hospital Sant Joan de Deu Barcelona; España

PTEN is a major tumor-suppressor protein whose expression and biological activity are frequently diminished in sporadic or inherited cancers. PTEN gene deletion or loss-of-function mutations favor tumor cell growth and are commonly found in clinical practice. In addition, diminished PTEN protein expression is also frequently observed in tumor samples from cancer patients in the absence of PTEN gene alterations. This makes PTEN protein levels a potential biomarker parameter in clinical oncology, which can guide therapeutic decisions. The specific detection of PTEN protein can be achieved by using highly defined anti-PTEN monoclonal antibodies (mAbs), characterized with precision in terms of sensitivity for the detection technique, specificity for PTEN binding, and constraints of epitope recognition. This is especially relevant taking into consideration that PTEN is highly targeted by mutations and posttranslational modifications, and different PTEN protein isoforms exist. The precise characterization of anti-PTEN mAb reactivity is an important step in the validation of these reagents as diagnostic and prognostic tools in clinical oncology, including their routine use in analytical immunohistochemistry (IHC). Here, we review the current status on the use of well-defined anti-PTEN mAbs for PTEN immunodetection in the clinical context and discuss their potential usefulness and limitations for a more precise cancer diagnosis and patient benefit. Sin financiación 6.000 JCR (2019) Q1, 15/139 Medicine, Research & Experimental 4.012 SJR (2019) Q1, 16/279 Biochemistry, Genetics and Molecular Biology (miscellaneous) No IDR 2019 UEM

Pediatric brain tumors with replication repair deficiency (RRD) are hypermutant and may respond favorably to immune checkpoint inhibition (ICI). We are collecting ongoing clinical and molecular data from patients with RRD hypermutant cancers treated with ICI as a part of our consortium registry study. Companion biomarkers include tumor mutational burden (TMB), neoantigens and genetic signatures obtained from whole genome and exome sequencing. Immune inference is obtained from RNAseq. Additionally, T-cell receptor rearrangement data are collected from the tumor and blood throughout treatment. From 2015–2018, 53 patients were treated with ICI and combination therapies. Of these 39 had brain tumors, with 93% having high grade gliomas. Two-year overall survival for the entire cohort is 47+/-8%, which compares favorably with historical controls. Tumor location had major impact on outcome. Non-CNS solid tumor patients have 2-year OS of 78+/-11%, all failures occurring within the first 2 months, and sustained responses are observed for 3 years. In contrast, OS for brain tumors is 39+/-10% with late recurrences observed even after 2 years of therapy (p=0.02). Large tumor size and total tumor burden are associated with higher rates of “flare” and poor outcome throughout all cancers. While all tumors are hypermutant, TMB and predicted neoantigens do not correlate with response. However, specific signatures extracted from SNVs and indels are significantly associated with response to ICI and favorable outcome (p=0.005). Notably, RRD IDH1 mutant glioblastomas have particularly poor response to ICI. Interestingly, glioblastomas (n=8) which failed single agent ICI had favorable responses to combination immunotherapies with prolonged survival of 65%+/-8% one year after failure vs 0 for untreated patients (p=0.01). The favorable outcome and responses to ICI are encouraging. Since brain tumors respond less favorably to ICI than other solid tumors, combination therapies based on tumor and immune signatures of these cancers may be beneficial.

Anti-PTEN monoclonal antibodies (mAb) are arising as important tools for immunohistochemistry (IHC) and protein quantification routine analysis in clinical oncology. Although an effort has been made to document the reliability of tumor tissue section immunostaining by anti-PTEN mAb, and to standardize their IHC use in research and in the clinical practice, the precise topological and biochemical definition of the epitope recognized by each mAb has been conventionally overlooked. In this study, six commercial anti-PTEN mAb have been validated and characterized for sensitivity and specificity by IHC and FISH, using a set of prostate and urothelial bladder tumor specimens, and by immunoblot, using PTEN positive and PTEN negative human cell lines. Immunoblot precise epitope mapping, performed using recombinant PTEN variants and mutations, revealed that all mAb recognized linear epitopes of 6-11 amino acid length at the PTEN C-terminus. Tumor-associated or disease-associated mutations at the PTEN C-terminus did not affect subcellular localization or PIP3 phosphatase activity of PTEN in cells, although resulted in specific loss of reactivity for some mAb. Furthermore, specific mimicking-phosphorylation mutations at the PTEN C-terminal region also abolished binding of specific mAb. Our study adds new evidence on the relevance of a precise epitope mapping in the validation of anti-PTEN mAb for their use in the clinics. This will be substantial to provide a more accurate diagnosis in clinical oncology based on PTEN protein expression in tumors and biological fluids. SAF2013-48812-R (a RP) y SAF2016-79847-R (a RP y JIL) del Ministerio de Economía y Competitividad. Subvención 2013111011 de Gobierno Vasco, Departamento de Salud (País Vasco, España). Subvención 239813 del Consejo de Investigación de Noruega. 7.717 JCR (2019) Q1, 28/244 Oncology No data SJR 2019 No data IDR 2019 UEM

Pediatric brain tumors with replication repair deficiency (RRD) are hypermutant and may respond to immune checkpoint inhibition (ICI). We performed a consortium registry study of ICI in recurrent RRD cancers. Clinical and companion biomarkers were collected longitudinally on all patients. Biomarkers included tumor mutational burden (TMB), neoantigens and genetic signatures obtained from whole genome and exome sequencing. Immune inference was obtained by RNAseq and T cell rearrangement was collected in the tumor and in blood throughout treatment. Of the 46 tumors on the study, 32 were brain tumors with glioblastoma in 96%. Rapid, objective responses (>50%) were observed in 50% of glioblastomas. Three year overall survival for the whole cohort was 48+/-8% which compares favorably with historical controls. Brain tumors fared worse with OS of 39+/-10% and late recurrences observed even after 2 years of therapy (p=0.02). Tumor size and acute “flare” constitute poor outcome throughout all cancers. While all tumors are hypermutant, TMB and predicted neoantigens correlated with response to ICI (p=0.02). Specific signatures extracted from SNVs and total mutations predicted response to ICI and favorable outcome (p=0.005). RNA inference and TCR reveal that the FLARE phenotype is mostly acute nonspecific immune response and not true progression. Finally, glioblastomas (n=8) which failed single agent ICI had favorable responses to combinational immunotherapies with prolonged survival of 65%+/-8% at one year after failure vs 0 for other patients (p=0.01). RRD glioblastomas exhibit favorable outcome and responses to ICI. Combinational therapies based on tumor and immune signatures of these cancers are necessary.

Many children with cancer in low- and middle-income countries are treated in hospitals lacking key infrastructure, including diagnostic capabilities, imaging modalities, treatment components, supportive care, and personnel. Childhood cancer treatment regimens adapted to local conditions provide an opportunity to cure as many children as possible with the available resources, while working to improve services and supportive care. This paper from the Adapted Treatment Regimens Working Group of the Pediatric Oncology in Developing Countries committee of the International Society of Pediatric Oncology outlines the design, development, implementation, and evaluation of adapted regimens and specifies levels of services needed to deliver them. Fil: Howard, Scott C.. University of Tennessee; Estados Unidos Fil: Davidson, Alan. University of Cape Town; Sudáfrica Fil: Luna Fineman, Sandra. University of Colorado; Estados Unidos Fil: Israels, Trijn. Vrije Unviversiteit Brussel; Bélgica Fil: Chantada, Guillermo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Universidad de Barcelona; España. Hospital Sant Joan de Deu Barcelona; España Fil: Lam, Catherine G.. St. Jude Children's Research Hospital; Estados Unidos Fil: Hunger, Stephen P.. University of Pennsylvania; Estados Unidos Fil: Bailey, Simon. Royal Victoria Infirmary Paediatric Neuro‐Oncology and Paediatric Oncology; Reino Unido Fil: Ribeiro, Raul C.. St. Jude Children's Research Hospital; Estados Unidos Fil: Arora, Ramandeep S.. Max Super‐Specialty Hospital. Department of Medical Oncology; India Fil: Pedrosa, Francisco. Real Hospital Português Real Oncopediatría; Brasil Fil: Harif, Mhamed. Hôpital 20. Department of Hematology ; Marruecos Fil: Metzger, Monika L.. St. Jude Children's Research Hospital; Estados Unidos

Corticosteroid treatment of paediatric leukaemia patients can lead to osteonecrosis (ON). We determined whether bone marrow oedema (BME) is an early sign of progressive ON and eventual bone collapse. In a retrospective study, two radiologists reviewed MR imaging characteristics of 47 early stage epiphyseal ON in 15 paediatric and adolescent leukaemia patients. Associations between BME on initial imaging studies and subchondral fracture, disease progression and bone collapse were assessed by Cochran-Mantel-Haenszel tests. Differences in time to progression and bone collapse between lesions with and without oedema were assessed by log rank tests. Forty-seven occurrences of ON were located in weight bearing joints, with 77% occurring in the femur. Seventeen lesions progressed to collapse, two lesions worsened without collapse, and 28 remained stable or improved. BME was significantly associated with subchondral fracture (p = 0.0014), disease progression (p = 0.0015), and bone collapse (p

The aim of this study was to assess the safety profile of ferumoxytol as an intravenous magnetic resonance imaging contrast agent in children.We prospectively evaluated the safety of ferumoxytol administrations as an "off-label" contrast agent for magnetic resonance imaging in nonrandomized phase 4 clinical trials at 2 centers. From September 2009 to February 2015, 49 pediatric patients (21 female and 28 male, 5-18 years) and 19 young adults (8 female and 11 male, 18-25 years) were reported under an investigator-initiated investigational new drug investigation with institutional review board approval, in health insurance portability and accountability act compliance, and after written informed consent of the child's legal representative or the competent adult patient was obtained. Patients received either a single dose (5 mg Fe/kg) or up to 4 doses of ferumoxytol (0.7-4 mg Fe/kg) intravenously, which were approximately equivalent to one third of the dose for anemia treatment. We monitored vital signs and adverse events directly for up to 1 hour after injection. In addition, we examined weekly vitals, hematologic, renal, and liver serum panels for 1 month after injection in over 20 pediatric patients. At fixed time points before and after ferumoxytol injection, data were evaluated for significant differences by a repeated measures linear mixed model.Four mild adverse events, thought to be related to ferumoxytol, were observed within 1 hour of 85 ferumoxytol injections: 2 episodes of mild hypotension and 1 case of nausea in 65 injections in pediatric patients without related clinical symptoms. One young adult patient developed warmness and erythema at the injection site. All adverse events were self-resolving. No spontaneous serious adverse events were reported. At a dose of 5 mg Fe/kg or lower, intravenous ferumoxytol injection had no clinical relevance or statistically significant effect (P0.05) on vital signs, hematological parameters, kidney function, or liver enzymes within 1 month of the injection.Ferumoxytol was overall well tolerated among 49 pediatric and 19 young adult patients experiencing various tumors or kidney transplants without major adverse events or signs of hematologic and kidney impairment or liver toxicity. Larger studies are needed to determine the incidence of anaphylactic reactions.

70 Objectives Clinical measures of Parkinson’s disease progression suggest a slow process with significant variability both between patients and also within the individual over the course of disease. A number of “objective” imaging and non-imaging measures have been proposed as putative progression biomarkers although there is limited validation data available. The Parkinson9s (PD) progression marker initiative (PPMI) is an international, multicenter, longitudinal study assessing biochemical, clinical, and imaging biomarkers of disease progression. Scintigraphic biomarkers are being evaluated as indicators of progression include dopamine transporter (DAT) imaging with 123-I ioflupane SPECT. This study evaluates subregion-dependent striatal changes in dopamine transporter (DAT) binding using 123-I Ioflupane SPECT in PD participants in the PPMI study. Methods Baseline (n= 241), 1 year, and 2 year 123-I Ioflupane SPECT scans were acquired from 22 centers. Data were reconstructed, attenuation corrected, and analyzed by the core lab using a volume of interest template for extraction of counts and calculation of specific binding ratios (SBRs) and percent SBRs changes over time in six striatal subregions. Results Ongoing serial evaluation shows SBR reduction at 1 yr in 80% of 241 PD subjects. Specific binding ratios demonstrate 11.6% and 7.4% reductions over one year in the ipsilateral and contralateral striatum, respectively. Differences in the rates of DAT signal change are evident in subregions of the striatum. The fastest rates of change annualized over two years were noted, in order, for ipsilateral striatum; posterior putamen (-9.2% +/-11.4), anterior putamen(-8.7% +/- 8.8), and caudate( -6.9% +/-8.9). In contrast, contralaterally, posterior putamen (-6.4% +/-15.4), demonstrated the slowest rate of change with the anterior putamen (-8.0% +/-10.3), and the caudate ( -7.5%+/-9.4). Conclusions These data have implications for the potential use of dopamine transporter imaging as a serial marker of change in longitudinal Parkinson9s studies. Specifically, areas with greatest signal change and lowest variability might be more sensitive for detecting slowing rates of change with a disease modifying therapy. In summary, this study shows consistently increasing signal loss over one and two years with regional differences demonstrated for DAT imaging and confirmation of previously noted between subject variability.

Analysis of 327 consecutive cases at a pediatric referral hospital of Guatemala reveals that retinoblastoma accounts for 9.4% of all cancers and the estimated incidence is 7.0 cases/million children, higher than the United States or Europe. The number of familial cases is low, and there is a striking disparity in indigenous children due to late diagnosis, advanced disease, rapid progression and elevated mortality. Nine germline mutations in 18 patients were found; two known and five new mutations. Hypermethylation of RB1 was identified in 13% of the tumors. An early diagnosis program could identify cases at an earlier age and improve outcome of retinoblastoma in this diverse population.