Modern treatment of retinoblastoma: A 2020 review

Targeted treatment of solid tumors in pediatric precision oncology

The treatment of childhood solid cancer has markedly evolved in recent years following a refined molecular characterization and the introduction of novel targeted drugs. On one hand, larger sequencing studies have revealed a spectrum of mutations in pediatric tumors different from adults. On the other hand, specific mutations or immune dysregulated pathways have been targeted in preclinical and clinical studies, with heterogeneous results. Of note, the development of national platforms for tumor molecular profiling and, in less measure, for targeted treatment, has been essential in the process. However, many of the available molecules have been tested only in relapsed or refractory patients, and have proven poorly effective, at least in monotherapy. Our future approaches should certainly aim at improving the access to molecular characterization, to obtain a deeper picture of the distinctive phenotype of childhood cancer. In parallel, the implementation of access to novel drugs should not only be limited to basket or umbrella studies but also to larger, multi-drug international studies. In this paper we reviewed the molecular features and the main available therapeutic options in pediatric solid cancer, focusing on available targeted drugs and ongoing investigations, aiming at providing a useful tool to navigate the heterogeneity of this promising but complex field.

Digital Gangrene and Antiphospholipid Syndrome in a Retinoblastoma Patient with Chromosome 13q Deletion: A Case Report

A 19-month-old girl with Cornelia de Lange-like dysmorphic features presented with left eye leukocoria. She was diagnosed with 13q deletion retinoblastoma grade 4 with high-risk features and bone marrow involvement. She underwent enucleation, and the first course of intravenous chemotherapy was initiated. On day 10 after the first chemotherapy dose, she developed digital gangrene of her left hand. She was diagnosed with acute artery occlusion and limb ischemia. Thrombophilia work-up revealed antiphospholipid antibodies, and paraneoplastic syndrome is another possible cause of digital gangrene. The patient's left thumb and index finger were amputated. After 1 month of hospitalization, she was discharged. Before the second course of chemotherapy, the patient died of systemic metastatic retinoblastoma with respiratory failure due to pneumonia. Our postulation of the mechanism for digital gangrene was the combination of chemotherapy, paraneoplastic syndrome, and antiphospholipid syndrome. Digital gangrene could be a poor prognostic indicator in patients with retinoblastoma.

Research trends and areas of focus on cryoablation and oncology: A bibliometric analysis from 2001 to 2020

BACKGROUND

Cryoablation is an interdisciplinary, widely used treatment approach for several types of solid tumors, making it difficult to obtain a comprehensive picture of its current status and popular research topics. This study aimed to use a bibliometric approach to understand important research themes and trends in cryoablation and oncology.

METHODS

Literature studies on cryoablation and oncology from 2001 to 2020 were extracted from the Web of Science. A bibliometric analysis was performed based on the annual publication volume, several journal articles and local citation score, and distribution of keywords and trends in the literature using tools such as COOC version 9.94, VOSviewer version 1.6.17, and the bibliometrix version 3.1.3 R package.

RESULTS

This study included 2793 publications. Total yearly publications have plateaued over the last 20 years. Five research themes were presented in the keyword network, including clinical applications of cryoablation in liver, lung, kidney, prostate, and skin cancers and comparison of cryoablation with other energy ablations. After 2012, 2 new research topics emerged: synergy between cryoablation and immunotherapy in tumors and cryoablation of Barrett esophagus. The high cited literatures are dominated by studies related to cryoablation for renal and prostate cancer treatment, but they also reflect the recent increasing interest in immunotherapy and bone metastases. Twenty important journals were identified, with Cryobiology publishing the most articles.

CONCLUSION

Bibliometric analysis of studies related to tumor cryoablation can help researchers rapidly comprehend popular topics and determine future trends, guiding future research directions.

Role of circular RNAs in retinoblastoma

Retinoblastoma (RB), the most common malignant retinal tumor among children under 3 years old, is lethal if left untreated. Early diagnosis, together with timely and effective treatment, is important to improve retinoblastoma-related outcomes. Circular RNAs (circRNAs), a new class of non-coding RNAs with the capacity to regulate cellular activities, have great potential in retinoblastoma diagnosis and treatment. Recent studies have identified circular RNAs that regulate multiple cellular processes involved in retinoblastoma, including cell viability, proliferation, apoptosis, autophagy, migration, and invasion. Six circular RNAs (circ-FAM158A, circ-DHDDS, circ-E2F3, circ-TRHDE, circ-E2F5, and circ-RNF20) promote disease progression and metastasis in retinoblastoma and function as oncogenic factors. Other circular RNAs, such as circ-TET1, circ-SHPRH, circ-MKLN1, and circ-CUL2, play tumor suppressive roles in retinoblastoma. At present, the studies on the regulatory mechanism of circular RNAs in retinoblastoma are not very clear. The purpose of this review is to summarize recent studies on the functional roles and molecular mechanisms of circular RNAs in retinoblastoma and highlight novel strategies for retinoblastoma diagnosis, prognosis, and treatment.

Spotlight on Targeted Chemotherapy in Retinoblastoma: Safety, Efficacy, and Patient Outcomes

As the most common primary intraocular malignancy of childhood, retinoblastoma (RB) has had a complex journey in its management, following a course from enucleation as the first life-saving treatment to numerous globe-salvaging therapies during the last century. Currently, this potentially lethal disease has achieved high survival rates owing to multidisciplinary management and the introduction of neoadjuvant and multimodal chemotherapy. Therefore, the goal of treatment is shifting toward conserving the globe and vision as much as possible. Up until recently, many advanced cases of RB were enucleated primarily; however, targeted chemotherapy via the ophthalmic artery and management of intraocular seeding by local administration of chemotherapeutic agents have revolutionized the globe-conserving therapies. The added benefit of avoiding systemic complications of cytotoxic drugs resulted in these methods gaining popularity, and they are becoming a main part of care in many referral centers. Initially, there were some safety concerns regarding these approaches; however, increasing experience has shown that these modalities are relatively safe procedures and many complications can be averted by changing the choice of the drug and using some prophylactic measures. It is hoped that, in the near future, with advances in early diagnosis and patient-targeted molecular therapies, as well as gene-editing techniques, the patient's vision can be saved even in advanced RB.

Evaluating the preventive effect of metoclopramide and aminophylline on pain after deep vitrectomy

BACKGROUND

Deep vitrectomy is one of the most frequently performed ophthalmic procedures. Postoperative pain is a common complaint among patients. Consequently, we investigated whether metoclopramide and aminophylline could decrease pain intensity following deep vitrectomy.

METHODS

This double-blinded clinical trial study that was approved by the Ethical Committee of Isfahan University of Medical Sciences (IR.MUI.REC.1396.3.217) (Thesis Reg. number: 396217) and registered at the Iranian Registry of Clinical Trials (IRCT) (Reg. number: IRCT20170716035104N5, available at https://www.irct.ir/trial/59146) aimed to evaluate 105 patients who were candidates for deep vitrectomy. They were randomly assigned into three groups: metoclopramide (received 0.1 mg/kg diluted in 10 ml of normal saline), aminophylline (received 4 mg/kg diluted in 10 ml of normal saline), and placebo (received 10 ml of normal saline). Postoperative pain was evaluated in all groups.

RESULTS

The postoperative pain levels of the three groups differed significantly from the start of the recovery to 30 minutes, 60 minutes, 2 hours, and 4 hours postoperatively, with metoclopramide and aminophylline groups experiencing less postoperative pain than the placebo group. Moreover, there was a significant difference between the groups regarding patient satisfaction (P<0.05).

CONCLUSION

Both metoclopramide and aminophylline significantly reduce postoperative pain after deep vitrectomy, although metoclopramide has a greater effect.

Targeted long-read sequencing allows for rapid identification of pathogenic disease-causing variants in retinoblastoma

BACKGROUND

Identification of disease-causing variants of the retinoblastoma gene (RB1), the predominant cause of retinoblastoma, is challenging. Targeted long-read genome sequencing offers a novel approach to resolve the diverse range of pathogenic variants in RB1 and provides haplotype information rapidly.

MATERIALS AND METHODS

Genomic DNA was isolated from a venipuncture blood draw of a retinoblastoma patient. Whole genome sequencing (WGS) was carried out using the short-read Ilumina platform. WGS and targeted sequencing of RB1 was accomplished using the long-read Oxford Nanopore Technologies (ONT) platform. Deep-learning frameworks allowed haplotagging, variant calling, and variant annotation of both short- and long-read data.

RESULTS

Targeted long-read sequencing of the RB1 gene allowed for enhanced depth of read coverage for discovery of rare variants and haplotype analysis. A duplication leading to a frameshift and early termination in RB1 was identified as the most deleterious variant by all sequencing methods, with long-read technology providing additional information of methylation signal and haplotype information. More importantly, there was greater than 98% concordance of RB1 variants identified between short-read and targeted long-read sequencing modalities.

CONCLUSIONS

Targeted long-read technology allows for focused sequencing effort for variant discovery. Application of this for the first time in a retinoblastoma patient allowed haplotagged variant identification and demonstrated excellent concordance with benchmark short-read sequencing. The added benefit of targeted long-read sequencing to resolve disease-causing genomic variation in RB1 rapidly from a blood draw will provide a more definitive diagnosis of heritable RB and guide management decisions for patients and their families.

A case of retinoblastoma resulting in phthisis bulbi after proton beam radiation therapy

Purpose

Proton beam radiation therapy (PBRT) is a treatment option for advanced retinoblastoma (RB) resistant to chemotherapy and focal ophthalmic treatment. Here we report a case of RB with phthisis bulbi following PBRT.

Observations

A 16-day-old boy with a family history of RB was referred to our institution. Initial examination revealed an extensive white mass in the right eye and a small tumor near the optic disk of the left eye. The patient was diagnosed with bilateral RB and treated with chemotherapy and focal ophthalmic therapy. The right eye showed shrinkage in the treatment course. The tumor control was not achieved bilaterally, and, therefore, PBRT was performed to preserve the eyes. However, the right eye became significantly phthisical following PBRT and ultimately required enucleation.

Conclusions and importance

PBRT for RB may result in phthisis bulbi. Further investigations of its role and possible complications are warranted.

Advances in biomaterials for the treatment of retinoblastoma

Retinoblastoma is the most common primary intraocular malignancy in children. Although traditional chemotherapy has shown some success in retinoblastoma management, there are several shortcomings to this approach, including inadequate pharmacokinetic parameters, multidrug resistance, low therapeutic efficiency, nonspecific targeting, and the need for adjuvant therapy, among others. The revolutionary developments in biomaterials for drug delivery have enabled breakthroughs in cancer management. Today, biomaterials are playing a crucial role in developing more efficacious retinoblastoma treatments. The key goal in the evolution of drug delivery biomaterials for retinoblastoma therapy is to resolve delivery-associated obstacles and lower nonlocal exposure while ameliorating certain adverse effects. In this review, we will first delve into the historical perspective of retinoblastoma with a focus on the classical treatments currently used in clinics to enhance patients' quality of life and survival rate. As we move along, we will discuss biomaterials for drug delivery applications. Various aspects of biomaterials for drug delivery will be dissected, including their features and recent advances. In accordance with the current advances in biomaterials, we will deliver a synopsis on the novel chemotherapeutic drug delivery strategies and evaluate these approaches to gain new insights into retinoblastoma treatment.

Dual-Target Multifunctional Superparamagnetic Cationic Nanoliposomes for Multimodal Imaging-Guided Synergistic Photothermal/Photodynamic Therapy of Retinoblastoma

Background

With high malignancy, retinoblastoma (RB) commonly occurs in infants and has incredible difficulty with the early diagnosis. In recent years, the integrated theranostics of multimodal imaging-guided therapy has shown promising potential for oncotherapy.

Purpose

To prepare folate/magnetic dual-target theranostic nanoparticles integrating with US/PA/MR imaging and the synergistic photothermal treatment (PTT)/photodynamic treatment (PDT) for the early diagnosis and timely intervention of RB cancer.

Methods

Folate/magnetic dual-target cationic nanoliposomes (CN) encapsulating indocyanine green (ICG) and perfluorohexane(PFH)(FA-CN-PFH-ICG-Fe₃O₄, FCNPIFE) were synthesized and characterized. Then we evaluated their targeting ability, US/PA/MR imaging effects, and the efficacy of synergistic PTT/PDT in vitro and in vivo. Finally, we explored the mechanism of synergistic PTT/PDT in Y79 tumor-bearing mice.

Results

FCNPIFEs were stable and uniform in 7 days. They showed excellent in vitro targeting ability with a 95.29% cell uptake rate. The in vitro US/PA/MRI imaging results of FCNPIFEs showed a concentration-dependent manner, and in vitro therapy FCNPIFEs exhibited an enhanced anticancer efficacy against Y79 cells. In vivo analysis confirmed that FCNPIFEs enabled a targeted synergistic PTT/PDT under US/PA/MR imaging guidance in Y79 tumor-bearing mice, achieving almost complete tumor regression. Immunofluorescence results displayed weaker fluorescence intensity compared with other single treatment groups, confirming that PTT/PDT synergistic therapy effect was achieved by down-regulating the expression of HIF-1α and HSP70.

Conclusion

FCNPIFEs were verified as promising theranostic nanoliposomes for RB oncotherapy and showed great potential in clinical application.

Bilateral enucleation for retinoblastoma: A study of 14 patients

PURPOSE

To study the clinical profile of patients who underwent bilateral enucleation for retinoblastoma (RB).

METHODS

Retrospective study of 14 cases.

RESULTS

Of >3000 RB cases, 14 (<1%) underwent bilateral enucleation for treatment of RB. The mean age at diagnosis of RB was 26 months (median, 24 months; range, 5-72 months). All patients had bilateral RB at presentation. Intraocular RB was evident in 23 (82%) eyes and orbital tumor extension was noted in 5 (18%) eyes. Based on the International Classification of Intraocular RB, tumors were classified as Group B (n = 1; 4%), D (n = 4; 14%), or E (n = 14; 50%) at presentation. Based on the International RB Staging System, tumors were classified as Stage 1 (n = 23; 82%) or Stage 3 (n = 5; 18%). Two patients (four eyes with intraocular RB) had undergone prior treatment before presenting to us and thus could not be classified. Primary treatment included systemic chemotherapy (n = 27; 96%) or enucleation (n = 1; 4%). Five patients were lost to follow-up for a mean duration of 15 months (median, 12 months; range, 7-24 months) during treatment and presented with the orbital extension of RB in one (n = 4; 29%) or both (n = 1; 7%) eyes. Secondary enucleation was performed in 27 (96%) eyes. Over a mean follow-up period of 49 months (median, 29 months; range, 3-340 months), there was no evidence of metastasis and 1 (7%) child died due to pneumonia.

CONCLUSION

Bilateral enucleation is rare in the treatment of RB. Advanced tumor presentation or noncompliance to treatment necessitates bilateral enucleation.

Induction of autophagy-dependent ferroptosis to eliminate drug-tolerant human retinoblastoma cells

Carboplatin is the most used first-line drug for the treatment of human retinoblastoma (RB), a rare form of cancer in infancy and childhood. However, the clinical application of carboplatin is restricted due to the emergence of acquired multi-drug resistance (MDR) after long-term treatment. Here, we report a new strategy to eliminate MDR RB cells by inducing autophagy-dependent ferroptosis. Compared with parent cells, carboplatin-resistant human RB cells have higher autophagy activity, which drives the formation of MDR to other chemotherapeutic drugs (e.g., etoposide and vincristine). In addition to confirming the traditional strategy of inhibiting autophagy to overcome MDR, we also establish an approach of inducing selective ferritinophagy to eliminate drug-resistant cells. We evaluate the effectiveness and safety of 4-octyl itaconate, a cell-permeable derivative of the metabolite itaconate, in inducing ferritinophagy-dependent ferroptosis in the treatment of MDR RB cells in vitro and in xenograft mouse models. These findings may provide essential clues for initiating clinical trials that target autophagy-dependent ferroptosis to kill drug-tolerant persistent cells during RB therapy.

The Role of Cryotherapy in Vitreous Concentrations of Topotecan Delivered by Episcleral Hydrogel Implant

Transscleral diffusion delivery of chemotherapy is a promising way to reach the vitreal seeds of retinoblastoma, the most common intraocular malignancy in childhood. In this in vivo study, the delivery of topotecan via lens-shaped, bi-layered hydrogel implants was combined with transconjunctival cryotherapy to assess whether cryotherapy leads to higher concentrations of topotecan in the vitreous. The study included 18 New Zealand albino rabbits; nine rabbits received a topotecan-loaded implant episclerally and another nine rabbits received transconjunctival cryotherapy superotemporally 2 weeks before implant administration. Median vitreous total topotecan exposures (area under the curve, AUC) were 455 ng·h/mL for the cryotherapy group and 281 ng·h/mL for the non-cryotherapy group, and were significantly higher in the cryotherapy group, similar to maximum levels. Median plasma AUC were 50 ng·h/mL and 34 ng·h/mL for the cryotherapy and non-cryotherapy groups, respectively, with no statistically significant differences between them. In both groups, AUC values in the vitreous were significantly higher than in plasma, with plasma exposure at only approximately 11–12% of the level of vitreous exposure. The results confirmed the important role of the choroidal vessels in the pharmacokinetics of topotecan during transscleral administration and showed a positive effect of cryotherapy on intravitreal penetration, resulting in a significantly higher total exposure in the vitreous.

The Role of Metalloproteinases and Their Tissue Inhibitors on Ocular Diseases: Focusing on Potential Mechanisms

Eye diseases are associated with visual impairment, reduced quality of life, and may even lead to vision loss. The efficacy of available treatment of eye diseases is not satisfactory. The unique environment of the eye related to anatomical and physiological barriers and constraints limits the bioavailability of existing agents. In turn, complex ethiopathogenesis of ocular disorders that used drugs generally are non-disease specific and do not act causally. Therefore, there is a need for the development of a new therapeutic and preventive approach. It seems that matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have a significant role in the development and progression of eye diseases and could be used in the therapy of these disorders as pharmacological targets. MMPs and TIMPs play an important role in the angiogenesis, epithelial-mesenchymal transition, cell invasion, and migration, which occur in ocular diseases. In this review, we aim to describe the participation of MMPs and TIMPs in the eye diseases, such as age-related macular degeneration, cataract, diabetic retinopathy, dry eye syndrome, glaucoma, and ocular cancers, posterior capsule opacification focusing on potential mechanisms.

Novel RB1 germline mutation in a healthy man

BACKGROUND

Retinoblastoma (Rb) most frequently presents as a unilateral sporadic disease up to 40% of cases, however, arise from a monoallelic germline pathogenic variant. Only 10% of the germline mutations are inherited, and high penetrance is seen in up to 90% of these cases. As an effort to optimize counseling and screening, mutations are classified according to inheritance patterns. However, RB1 spectrum is highly heterogeneous, and information for unaffected carriers remains scarce.

MATERIALS AND METHODS

The Mexican family of a 5-month-old patient diagnosed with Rb was studied. The family consisted of five individuals (father, mother, and three siblings). Genetic testing using a next-generation sequencing assay targeting RB1 with oligonucleotide baits designed to capture its exons and 20 bases flanking intronic sequences was performed in every family member. Clinical history and a complete ophthalmological examination (best-corrected visual acuity, slit-lamp biomicroscopy, macular optical coherence tomography, fundus autofluorescence, optical coherence tomography angiography, and electrophysiological studies) were performed in members testing positive to RB1 mutation.

RESULTS

The father and her five-month-old daughter tested positive for a non-synonymous RB1 mutation c.459del (p.Lys154Serfs*21). The girl presented with bilateral retinoblastoma, successfully treated with cryotherapy and intravenous chemotherapy. The father had no relevant findings on imaging studies or ophthalmologic evaluation.

CONCLUSIONS

This report describes a rare case of a novel low-penetrance RB1 germline mutation. Long-term follow-up of the father will include periodic evaluation of the eyes and orbits, and surveillance for systemic sarcoma and secondary malignancies. Implications for unaffected individuals need to be further studied.

Survival outcomes of unilateral retinoblastoma based on pathological risk stratification-experience at a tertiary care centre in Pakistan

Retinoblastoma (RB) is the most common childhood intraocular malignancy. In high-income countries over the past decade, upfront enucleation for unilateral RB is least favoured due to other alternatives that can help in globe preservation, but in low-middle income countries it is still the preferred option due to lack of resources and expertise. The treatment of RB after enucleation is tailored based on the histopathological risk features, as adjuvant chemotherapy with high-risk features reduces the risk of metastasis. The aim of our study was to analyse the survival outcomes of adjuvant therapy based on histopathological risk stratification in patients who underwent upfront enucleation for unilateral RB with advanced disease. A retrospective study was carried out at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Pakistan. A total 113 patients (aged 3 months till 16 years) diagnosed with unilateral RB who had upfront enucleation from July 2009 till January 2019 were included in this study. The mean age of diagnosis was 37.4 months (±24.5) and male-to-female ratio of 1.3:1. The most common clinical presentation was leukocoria (74.3%). Patients who underwent enucleation had advanced disease; group D present in 62.8% followed by group E (32.7%). Histopathology revealed high-risk features in 29 patients (25.7%) and intermediate risk in 54 patients (47.8%). Disease progression and relapse was seen in patients with high-risk histopathological features. The 4-year over-all survival and EFS observed for this cohort was 74% and 71%. Awareness about the early symptoms among the general population and health care personnel at a nationwide level is needed to facilitate early detection and lessen disease related morbidity and mortality.

AFAP1 antisense RNA 1 promotes retinoblastoma progression by sponging microRNA miR-545-3p that targets G protein subunit beta 1

The oncogenic role of actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) has been reported in retinoblastoma (RB). However, the underlying regulatory mechanisms remain poorly understood. In this study, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blotting were performed to analyze the expression of AFAP1-AS1, microRNA miR-545-3p, or G protein subunit beta 1 (GNB1). Cell Counting Kit-8 (CCK-8) and Transwell migration assays were used to detect cell proliferation and migration. In addition, caspase-3 activity was monitored by caspase-3 activity assay. Luciferase reporter assays combined with RNA immunoprecipitation (RIP) and pull-down assays were performed to elucidate the target relationship between miR-545-3p and AFAP1-AS1 or GNB1. Xenograft tumor experiments were performed to evaluate RB cell growth in vivo. Increased AFAP1-AS1 and GNB1 expression in RB tissues and cells was confirmed by RT-qPCR; conversely, miR-545-3p was found to be downregulated in RB tissues and cells. AFAP1-AS1 overexpression resulted in increased proliferation and migration of RB cells, whereas AFAP1-AS1 silencing resulted in decreased proliferation and migration of RB cells. Moreover, AFAP1-AS1 was found to target miR-545-3p. The anti-miR-545-3p treatment phenocopied the effect of AFAP1-AS1 overexpression and promoted RB cell growth in vivo. miR-545-3p was found to directly target GNB1. GNB1 silencing resulted in reduced proliferation and migration of RB cells and attenuated the oncogenic effect of the miR-545-3p inhibitor. Thus, in this study, a novel ceRNA regulation network of AFAP1-AS1 in RB was identified, where AFAP1-AS1 regulated GNB1 expression by targeting miR-545-3p, ultimately driving RB progression.

Changes in Treatment Patterns and Globe Salvage Rate of Advanced Retinoblastoma in Korea: Efficacy of Intra-Arterial Chemotherapy

(1) Background: To analyze changes in treatment patterns for advanced retinoblastoma over time and differences in globe salvage rates; (2) Methods: Retrospective, observational case-control study of 97 eyes of 91 patients with advanced retinoblastoma (Group D and E).; (3) Results: Patients were divided into two groups based on whether they were treated before or after intraarterial chemotherapy (IAC) was introduced in our center in 2010. Before 2010, primary treatment pattern was enucleation, which was performed in 57.6% of cases, whereas primary treatment pattern after 2010 was IAC combined with intravenous chemotherapy (IVC), which was performed in 78.1%. Intravitreal chemotherapy (IVitC) has been performed to treat vitreous and subretinal seeding since 2015. The 5-year globe salvage rate of IVC alone was 24.0% for Group D and 0% for Group E, whereas that of IVC–IAC was 50.4% for Group D and 49.7% for Group E. Whether IVitC was performed or not did not significantly contribute to globe salvage rate. There was one metastatic death in the IVC alone group.; (4) Conclusions: Primary treatment pattern changed from enucleation to IAC-based treatment, which can now save nearly half of eyes with advanced retinoblastoma with excellent safety profile and survival rate.

Effect of Eriodictyol on Retinoblastoma via the PI3K/Akt Pathway

Retinoblastoma (RB) is one of the most common intraocular malignancies in children, which causes vision loss and even threatens life. Eriodictyol is a natural flavonoid with strong anticancer activity. Some studies have shown that eriodictyol exerts anticancer effects in glioma, colon cancer, and lung cancer; however, no studies have reported the anticancer effects of eriodictyol on RB. Therefore, the aim of this study was to investigate the anticancer activity of eriodictyol against the RB Y79 cell line and its potential mechanism of action. Interestingly, we found that eriodictyol inhibited the proliferation, migration, and invasion of Y79 cells in a dose-dependent manner and decreased the expression of MMP-2 and MMP-9 proteins in the cells. In addition, eriodictyol-induced apoptosis in Y79 cells was assessed by flow cytometry and immunoblotting. Here, our study revealed that eriodictyol dose dependently inhibited the activation of the PI3K/Akt signaling pathway. Notably, the effect of eriodictyol on RB apoptosis was reversed by a PI3K agonist 740 Y-P. In conclusion, our study shows that eriodictyol effectively inhibits proliferation, migration, and invasion and induces apoptosis in RB cell lines, which may be the result of blocking the PI3K/Akt signaling pathway. Thus, eriodictyol may provide a new theoretical basis for exploring targeted antitumor natural therapies.

Long non-coding RNA (lncRNA) five prime to Xist (FTX) promotes retinoblastoma progression by regulating the microRNA-320a/with-no-lysine kinases 1 (WNK1) axis

Long non-coding RNA (lncRNA) five prime to Xist (FTX) exerts important functions in human cancer, while its role in retinoblastoma (RB) remains unclear. This study aimed to investigate the role of FTX in RB. The expression levels of FTX were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was evaluated by cell counting kit-8 (CCK-8), 5‐ethynyl‐2′‐deoxyuridine (EdU) staining and colony formation assays. Cell migration and invasion were detected by Transwell assay. The relationship among FTX, microRNA-320a (miR-320a) and with-no-lysine kinase 1 (WNK1) was also investigated. In the present study, we found that the expression levels of FTX were notably elevated in RB tissues and cancer cell lines. Overexpression of FTX exacerbated the aggressive phenotypes (cell proliferation, migration and invasion) of RB cells. Downregulation of miR-320a obviously attenuated the inhibitory effects of knockdown of FTX in RB malignant phenotypes, and knockdown of WNK1 also reversed the impacts of miR-320a inhibitor on malignant phenotypes. In vivo experiments further confirmed that knockdown of FTX efficiently prevents tumor growth in vivo. Our results revealed that FTX promoted RB progression by targeting the miR-320a/WNK1 axis (graphical abstract), suggesting that FTX might be a novel therapeutic target for RB.

Ultrasound and Microbubbles for the Treatment of Ocular Diseases: From Preclinical Research towards Clinical Application

The unique anatomy of the eye and the presence of various biological barriers make efficacious ocular drug delivery challenging, particularly in the treatment of posterior eye diseases. This review focuses on the combination of ultrasound and microbubbles (USMB) as a minimally invasive method to improve the efficacy and targeting of ocular drug delivery. An extensive overview is given of the in vitro and in vivo studies investigating the mechanical effects of ultrasound-driven microbubbles aiming to: (i) temporarily disrupt the blood–retina barrier in order to enhance the delivery of systemically administered drugs into the eye, (ii) induce intracellular uptake of anticancer drugs and macromolecules and (iii) achieve targeted delivery of genes, for the treatment of ocular malignancies and degenerative diseases. Finally, the safety and tolerability aspects of USMB, essential for the translation of USMB to the clinic, are discussed.

Adjuvant therapy of histopathological risk factors of retinoblastoma in Europe: A survey by the European Retinoblastoma Group (EURbG)

INTRODUCTION

Advanced intraocular retinoblastoma can be cured by enucleation, but spread of retinoblastoma cells beyond the natural limits of the eye is related to a high mortality. Adjuvant therapy after enucleation has been shown to prevent metastasis in children with risk factors for extraocular retinoblastoma. However, histological criteria and adjuvant treatment regimens vary and there is no unifying consensus on the optimal choice of treatment.

METHOD

Data on guidelines for adjuvant treatment in European retinoblastoma referral centres were collected in an online survey among all members of the European Retinoblastoma Group (EURbG) network. Extended information was gathered via personal email communication.

RESULTS

Data were collected from 26 centres in 17 countries. Guidelines for adjuvant treatment were in place at 92.3% of retinoblastoma centres. There was a consensus on indication for and intensity of adjuvant treatment among more than 80% of all centres. The majority of centres use no adjuvant treatment for isolated focal choroidal invasion or prelaminar optic nerve invasion. Patients with massive choroidal invasion or postlaminar optic nerve invasion receive adjuvant chemotherapy, while microscopic invasion of the resection margin of the optic nerve or extension through the sclera are treated with combined chemo- and radiotherapy.

CONCLUSION

Indications and adjuvant treatment regimens in European retinoblastoma referral centres are similar but not uniform. Further biomarkers in addition to histopathological risk factors could improve treatment stratification. The high consensus in European centres is an excellent foundation for a common European study with prospective validation of new biomarkers.

Intra-arterial chemotherapy for retinoblastoma in 341 consecutive eyes (1,292 infusions): comparative analysis of outcomes based on patient age, race, and sex

PURPOSE

To evaluate tumor control and globe salvage following intra-arterial chemotherapy (IAC) for retinoblastoma based on International Classification of Retinoblastoma (ICRB) and patient demographics.

METHODS

The medical records of 313 patients (341 eyes) treated with IAC were reviewed retrospectively. Chemotherapy agents included melphalan, topotecan, and carboplatin. Comparative analysis was performed for tumor control and globe salvage based on ICRB and patient demographics including age (≤12 vs >12 months), race (white vs nonwhite), and sex.

RESULTS

Of the 341 eyes treated with 1,292 consecutive infusions of IAC as primary or secondary therapy for retinoblastoma, Kaplan-Meier 5-year estimates of globe salvage was 74%. Of those treated with IAC as primary therapy (n = 160 eyes; 655 infusions), 5-year globe salvage overall was 76%: and more specifically, 100% for groups B and C, 86% for group D, and 55% for group E. Of those treated with IAC as secondary therapy (n = 207 eyes; 859 infusions), 5-year globe salvage was 71%. Comparative analysis by race and sex demonstrated no differences in outcomes, but analysis by age revealed that younger patients had a higher rate of globe salvage (77% vs 72%; P < 0.001). Complications (per catheterization) included retina ischemia (1%), choroidal ischemia (1%), neovascularization of the disk, retina, iris (NVI), glaucoma (about 1% each), and central/peripheral systemic ischemia (<1%). Younger patients showed less NVI (P = 0.028), white patients showed less retinal ischemia (P = 0.037), and no difference by sex. There were no patients with metastatic disease or death.

CONCLUSIONS

Our results suggest that IAC provides substantial tumor control for advanced and/or recurrent retinoblastoma with a high rate of globe salvage and few complications. There was little difference in outcomes per age, race, and sex.

Recent advancements in the management of retinoblastoma and uveal melanoma

Retinoblastoma in children and uveal melanoma in adults can pose a serious threat to both vision and life. For many decades, enucleation was often the only option to treat these intraocular malignancies. For retinoblastoma, intra-arterial chemotherapy is often utilized as the primary treatment at advanced academic centers and has dramatically improved local tumor control and eye salvage rates. For uveal melanoma, both plaque brachytherapy and proton beam irradiation have served as widely utilized therapies with a local failure rate of approximately 1–10%, depending on the series. Major recent advancements have allowed for a better understanding of the genomics of uveal melanoma and the impact of certain mutations on metastatic susceptibility. Gene expression profile stratifies uveal melanomas into two classes: low-risk (class 1) and high-risk (class 2). A loss-of-function mutation of BAP1 is associated with a class 2 gene expression profile and therefore confers worse prognosis due to elevated risk of metastasis. On the other hand, gain-of-function mutations of EIF1AX and SF3B1 correspond to a gene expression profile of class 1A and class 1B and confer a better prognosis. Preferentially expressed antigen in melanoma (PRAME) is an antigen that increases metastatic susceptibility when expressed in uveal melanoma cells. In addition to plaque brachytherapy and proton beam irradiation, both of which have demonstrated superb clinical outcomes, scientists are actively investigating newer therapeutic modalities as either primary therapy or adjuvant treatment, including a novel nanoparticle therapy and immunotherapy.

Publication Trends of Research on Retinoblastoma During 2001-2021: A 20-Year Bibliometric Analysis

Background: Retinoblastoma is the most common primary intraocular malignancy of childhood. Despite high survival and eye salvage as the result of various types of therapies, retinoblastoma remains a disease that places a considerable burden on developing countries. Our study attempted to analyse the research trends in retinoblastoma research and compare contributions from different countries, institutions, journals, and authors.

Methods: We extracted all publications concerning retinoblastoma from 2001 to 2021 from the Web of Science database. Microsoft Excel and VOSviewer were employed to collect publication data, analyse publication trends, and visualize relevant results.

Results: A total of 1,675 publications with 30,148 citations were identified. The United States contributed the most publications (643) and citations (16,931 times) with the highest H-index value (67) as of February 4, 2021. China ranked second in the number of publications (259), while ranking fourth in both citations (2,632 times) and the H-index (26) ranked fourth. The British Journal of Ophthalmology was the most productive journal concerning retinoblastoma, and Abramson DH had published the most papers in the field. Keywords were categorized into three clusters; tumor-related research, clinical research, and management-related research. The keywords “intravitreal,” “intraarterial,” and “intravenous” appeared the most frequently, with the average appearing year being 2018.1, 2017.7, and 2017.1, respectively. Management-related research has been recognized as a heavily researched topic in the field.

Conclusion: We conclude that the United States, China, and India made the most exceptional contributions in the field of retinoblastoma research, while China still has a disparity between the quantity and quality of publications. Management-related research, including intravitreal, intraarterial, and intravenous chemotherapy was considered as a potential focus for future research.

The role for intra-arterial chemotherapy for refractory retinoblastoma: a systematic review

BACKGROUND

Intra-arterial chemotherapy is a new retinoblastoma treatment associated with high rates of globe salvage that has been widely adopted for primary treatment of retinoblastoma but is less frequently used as secondary treatment for refractory retinoblastoma. This systematic review aims to summarize the reported outcomes of intra-arterial chemotherapy for refractory retinoblastoma.

METHODS

We conducted a systematic review of studies published on PubMed, Medline, and Embase from 2011 to 2021 reporting globe salvage rates following intra-arterial chemotherapy for secondary treatment of refractory retinoblastoma.

RESULTS

Our search yielded 316 studies, and 24 met inclusion criteria. The 24 included studies were comprised of 1366 patients and 1757 eyes. Among these, 1184 (67%) eyes received secondary indication treatment, and globe salvage was achieved for 776 of these 1184 eyes (64%). Sixteen studies reported cannulation success rates from 71.8 to 100%. Pooled analysis of subjects revealed 21 patients (2.6%) with metastatic disease and 26 deaths (3%) during study follow-up periods (7-74 months). The most common ocular complications were vitreous hemorrhage (13.2%), loss of eyelashes (12.7%), and periocular edema (10.5%). The most common systemic complications were nausea/vomiting (20.5%), neutropenia (14.1%), fever (8.2%), and bronchospasm (6.2%).

CONCLUSIONS

Intra-arterial chemotherapy is associated with high rates of globe salvage and low rates of serious complications in patients with refractory retinoblastoma. Unfortunately, current literature is predominantly comprised of retrospective case studies, and further high-quality evidence is necessary to inform clinical practice.

The Impact of Cell-Free DNA Analysis on the Management of Retinoblastoma

Retinoblastoma is a childhood eye cancer, mainly caused by mutations in the RB1 gene, which can be somatic or constitutional. Unlike many other cancers, tumour biopsies are not performed due to the risk of tumour dissemination. As a result, until recently, somatic genetic analysis was only possible if an affected eye was removed as part of a treatment. Several recent proof of principle studies have demonstrated that the analysis of tumour-derived cell-free DNA, either obtained from ocular fluid or blood plasma, has the potential to advance the diagnosis and influence the prognosis of retinoblastoma patients. It has been shown that a confirmed diagnosis is possible in retinoblastoma patients undergoing conservative treatment. In vivo genetic analysis of retinoblastoma tumours is also now possible, allowing the potential identification of secondary genetic events as prognostic biomarkers. In addition, noninvasive prenatal diagnosis in children at risk of inheriting retinoblastoma has been developed. Here, we review the current literature and discuss the potential impact of cell-free DNA analysis on both the diagnosis and treatment of retinoblastoma patients and their families.

Retinoblastoma in an older Hispanic child masquerading as pars planitis: A case report

INTRODUCTION

To report a case of a Hispanic girl with late-onset Retinoblastoma (Rb) who was misdiagnosed as a pars planitis prior to referral. Nearly 95% of all Rb cases are detected before age 5, and this patient was 8 years-old.

METHODS

Case report of a late-onset Retinoblastoma with anterior chamber (AC) involvement plus the presence of an Ahmed valve. The patient had a history of a couple of months of topical therapy comprising medication for glaucoma, systemic steroids, and a filtration surgery (Ahmed valve), after that a biopsy was performed prior to referral. Upon arrival at our clinic, we performed an examination under anesthesia (EUA) and a B-scan ultrasound (US).

RESULTS

Unilateral Retinoblastoma with an Ahmed valve in an AC filled with Rb seeds was diagnosed with the EUA and US in the left eye. An orbital exenteration with map biopsies of the left orbital cavity was performed with confirmation by histopathology of a poorly differentiated endophytic retinoblastoma with Bruch's membrane invasion. Follow-up sessions were then arranged as well as subsequent systemic chemotherapy cycles.

CONCLUSION

Given the rare incidence of retinoblastoma in children older than 5 years old, it can be easily mistaken for other differential diagnoses and treated with filtration surgeries that could put the patient's life at risk. In this report, late-onset Rb diagnosis is highlighted as a differential diagnosis in children and adults with atypical uveitis, which required a multidisciplinary approach.

SCARA5 suppresses the proliferation and migration, and promotes the apoptosis of human retinoblastoma cells by inhibiting the PI3K/AKT pathway

Retinoblastoma (RB) is the most common ocular malignancy that occurs during childhood. Scavenger receptor class A member 5 (SCARA5) is considered to function as an anti-oncogene in several types of malignant tumor. The present study investigated the functional role and underlying mechanism of SCARA5 in human RB cells. Reverse transcription-quantitative PCR and western blotting were used to detect the relative expression levels of SCARA5 in four human RB cell lines. In addition, transfection was performed to either knockdown or induce overexpression of SCARA5 in human RB Y79 cells. The proliferation, migration and apoptosis of RB cells was then measured by Cell Counting Kit 8 assay, 5-ethynyl-2′-deoxyuridine assay, clone formation assay, Transwell assay, Hoechst staining and TUNEL staining, respectively. Western blotting was performed to detect changes in the expression levels of key proteins involved in the PI3K/AKT and apoptotic pathways. The present study revealed that SCARA5 was expressed at lower levels in four tumorigenic human RB cell lines compared with in a human retinal pigment non-tumorigenic cell line. Functional analysis demonstrated that overexpression of SCARA5 decreased the proliferation and migration, and promoted the apoptosis of human RB cells in vitro, whereas in vivo experiments revealed a decrease in RB progression following SCARA5 overexpression. In addition, overexpression of SCARA5 inhibited phosphorylated (p)-PI3K and p-AKT expression, and knockdown of SCARA5 increased p-PI3K and p-AKT expression; however, no changes in total PI3K and AKT expression were observed. Bcl-2 exhibited similar changes in expression to those displayed by p-PI3K and p-AKT, whereas Bax and cleaved caspase-3 exhibited trends in expression that were the opposite to those shown by p-PI3K and p-AKT. In conclusion, the present results demonstrated that SCARA5 could inhibit the proliferation and promote the apoptosis of RB cell lines by suppressing the PI3K/AKT signaling pathway, thus suggesting a novel strategy for treating RB.