MYCN amplification levels in primary retinoblastoma tumors analyzed by Multiple Ligation-dependent Probe Amplification

Background: Retinoblastoma (Rb) is a childhood tumor of the developing retina where predisposition is caused by RB1 pathogenic variants. MYCN amplification (MYCNA) has been implicated in around 2% of sporadic unilateral Rb tumors with no detectable RB1 variants. We audited data from tumors collected between 1993 and 2019 to determine if this is the case for patients treated at Barts Health NHS Trust, and how often it occurred alongside RB1 variants. Materials and methods: Screening for MYCNA was carried out by Multiple Ligation Probe Analysis of tumor and blood samples collected for RB1 genetic screening. The cohort consisted of 149 tumors, of which 114 had matched blood samples. Results: 10/149 (6.7%) tumors were positive for MYCNA in a population containing a disproportionate number of cases negative for RB1 pathogenic variants. Of 65 unbiased tumors collected from 2014 to 2019, 2 (3.1%) had MYCNA. All MYCNA samples were from sporadic, unilateral patients and 3/10 (30%) had RB1 pathogenic variants. MYCNA was not detected in any blood sample. No MYCNA tumor had 6p gain which is usually a common alteration in Rbs. Conclusions: MYCNA occurs in a small fraction of Rbs and can occur in the presence of pathogenic RB1 variants. However, where it occurs alongside RB1 alterations, the age of onset appears to be later. MYCNA has yet to be seen as a heritable change. In sporadic cases with early diagnosis, Rbs with no RB1 pathogenic variant identified should be tested for MYCNA. Conversely, tumors with MYCNA should still be screened for RB1 pathogenic variants

High-Risk Histopathology Features in Primary and Secondary Enucleated International Intraocular Retinoblastoma Classification Group D Eyes

PURPOSE: To evaluate the rate and identify the risk factors for high-risk histopathologic features in group D retinoblastoma eyes enucleated as primary or secondary treatment. DESIGN: Retrospective analysis. PARTICIPANTS: A total of 64 enucleated group D eyes (62 patients), of which 40 (40 patients) were primary and 24 (22 patients) were secondary to other treatments. METHODS: Clinicopathologic correlation of consecutive group D eyes enucleated from 2002 to 2014. High-risk histopathologic features were defined as the presence of anterior chamber seeds, iris infiltration, ciliary body/muscle infiltration, massive (≥3 mm) choroidal invasion, retrolaminar optic nerve invasion, or combined non-massive choroidal and prelaminar/laminar optic nerve invasion. MAIN OUTCOME MEASURES: High-risk histopathologic features, metastasis, and death. RESULTS: Of the 64 group D eyes, 37 (58%) were classified as cT2bN0M0H0, 24 (38%) were classified as cT2bN0M0H1, and 3 (5%) were classified as cT2aN0M0H1, according to the 8th edition cTNMH Retinoblastoma Staging. High-risk histopathologic features were detected in 10 eyes (16%) in the entire cohort, 5 eyes (13%) of the primary enucleated group (pT3aNxM0, n = 2 and pT3bNxM0, n = 3, 8th edition pTNM), and 5 eyes (21%) of the secondary enucleated group (pT2bNxM0, n = 2, pT3aNxM0, n = 2 and pT3cNxM0, n = 1). Absence of vitreous seeds at presentation was the only predictive factor found for high-risk histopathologic features in the primary enucleation group (P = 0.042), whereas none were found in the secondary group (P ≥ 0.179). Invasion of the anterior structures (anterior chamber, iris, ciliary body/muscle) was detected significantly more after secondary enucleation (P = 0.048). All patients with high-risk histopathologic features were treated with adjuvant chemotherapy, and no metastases were recorded in a median follow-up time of 73.2 months (mean, 71.5; range, 13.7-153.0). CONCLUSIONS: The choice of primary treatment for group D retinoblastoma should be carefully weighed, because according to this study, 13% of eyes harbor high-risk histopathologic features at presentation, with the absence of vitreous seeds being a potential risk factor. It is of special importance in group D eyes being considered for nonsystemic treatment, such as primary intraophthalmic artery chemotherapy. Secondary enucleated group D eyes with high-risk histopathologic features more commonly involved anterior structures, warranting meticulous clinical and histologic examinations for this subset of patients

The management of retinoblastoma

Retinoblastoma (Rb) is the most common primary intraocular malignancy of childhood, but an uncommon paediatric cancer, with a constant incidence worldwide of 1:15,000-1:20,000 live births. Despite its rarity, Rb has served as a cornerstone in the field of oncology in many of the aspects that comprise cancer management, including classification schemes, treatment modalities, genetic testing and screening. Until just over half a century ago, the major treatment for Rb was eye removal, and prognosis was poor with outcome fatal for most children. The dramatic evolution, in a short period of time across all fields of Rb management, as well as the development of specialized centres, better infrastructure and introduction of awareness campaigns, has resulted in nearly 100% survival in developed countries and allowed eye salvage in many of the cases. External beam radiotherapy was used as the main treatment choice for four decades, but replaced by chemotherapy at the turn of the century. Initially, and still in many centres, chemotherapy is administered intravenously, but recently is targeted directly into the eye by means of intra-ophthalmic artery and intravitreal chemotherapy. To date, a range of treatments is available to the Rb expert, including enucleation, but there is lack of consensus in a number of scenarios as to what to use and when. In such a rare cancer, treatment outcomes are reported usually via retrospective analyses, with few prospective randomized controlled trials. Classification schemes have also evolved following the introduction of new treatment modalities, but discrepancies exist among centres with respect to the preferred schema and its interpretation. Retinoblastoma management is a remarkable success story, but the future will require a collaborative effort in the form of multicentre randomized controlled trials in order to further improve the quality of care for this subset of young children with ocular cancer

Detection and reporting of RB1 promoter hypermethylation in diagnostic screening

BACKGROUND: RB1 gene screening aids clinical management and genetic counselling in retinoblastoma families. Here we present epigenetic changes identified during routine molecular RB1 screening of tumor and blood samples. Complications in interpreting RB1 methylation are discussed. MATERIALS AND METHODS: Screening for RB1 promoter hypermethylation was carried out by Methylation Specific PCR (MS-PCR) after bisulphite modification of DNA. The cohort consisted of 315 tumors, and 204 blood samples, from 497 retinoblastoma patients (22 patients had both blood and tumor screened). RESULTS: 11.4% of retinoblastoma tumors had promoter hypermethylation. It was not routinely detected in blood samples, or in tumors with two other oncogenic RB1 changes. One blood sample had promoter hypermethylation due to an X;13 translocation. One tumor had low level methylation as well as two other oncogenic changes. Histopathological analysis of a small subset of age-matched tumors was similar regardless of promoter hypermethylation status. CONCLUSIONS: Promoter hypermethylation was detected in 11.4% of the retinoblastoma tumors and should be tested for in routine RB1 screening programmes. Constitutional samples are not expected to display RB1 hypermethylation. In a small proportion of cases it may not be possible to use this somatic change in patient management

Copper uptake and trafficking in the brain

The aim of this chapter is to give a general view on the current status of the scientific basis for the role of copper in human health and disease, outlining the roles of copper in human metabolism and bioenergetics, its coordination chemistry as well as the biological ligands involved in the multiple steps of metal incorporation. In particular, our attention has been focused towards the interaction of copper status and brain function in health and disease, with particular consideration to the role of copper in the pathogenesis of Wilson’s, of Menkes’s, and of human neurodegenerative diseases. Data on interactions between essential trace elements and copper, from the level of absorption in the gut to other systems in the body, are also presented. Particular attention is paid to copper-dependent enzymes in the central nervous system and to copper uptake and trafficking in brain cells