Retinoblastoma frontiers with intravenous, intra-arterial, periocular, and intravitreal chemotherapy

Injectable Dendrimer Hydrogel Delivers Melphalan in Both Conjugated and Free Forms for Retinoblastoma

We report the successful synthesis of an injectable dendrimer hydrogel (DH) carrying melphalan, a clinical drug for retinoblastoma treatment, in both conjugated and free forms. Polyamidoamine (PAMAM) dendrimer generation 5 (G5) is surface-modified with an acid-sensitive acetal-dibenzocyclooctyne linker and then undergoes azide-alkyne cycloaddition with melphalan-PEG-N3 conjugate to form G5-acetal-melphalan. During the DH gelation between G5-acetal-melphalan and PEG-diacrylate, free melphalan is added, resulting in a hydrogel (G5-acetal-melphalan-DH/melphalan) that carries the drug in both conjugated and free forms. Melphalan is slowly released from G5-acetal-melphalan-DH/melphalan, with the conjugated melphalan released more quickly at pH 5.3 due to acid-triggered acetal bond cleavage. The formulation's in vitro safety and efficacy were established on human corneal epithelia (HCE-2) and retinoblastoma cells (Y79). In an in vivo Y79 tumor xenograft model of retinoblastoma, intratumorally injected G5-melphalan-DH formulation prolonged tumor suppression. This injectable, multimodal, pH-responsive formulation shows promise for intravitreal injection to treat retinoblastoma.

EIF4A3-induced hsa_circ_0078136 inhibits the tumorigenesis of retinoblastoma via IL-17 signaling pathway

PURPOSE

Retinoblastoma (RB) is one of the most common intraocular cancers, with the highest prevalence among infants and young children under the age five. Numerous findings across the literature illustrate the involvement and significance of circular RNAs (circRNAs) in human malignancies, including RB. The current investigation attempted to decipher the exact roles and underlying mechanisms of a novel circRNA, hsa_circ_0078136, in RB progression.

METHODS

The hsa_circ_0078136 expression was evaluated in RB tumors and cell lines via qRT-PCR. The significance of hsa_circ_0078136 in RB was examined by performing CCK8 assay, transwell assays, western blotting of apoptotic and IL-17 signaling ligand molecules, and a subcutaneous xenograft tumor model. In addition, the interaction of circRNA and eukaryotic translation initiation factor 4A3 (EIF4A3) was determined with bioinformatics, western blot, and RIP assay.

RESULTS

The hsa_circ_0078136 expression was reduced in RB tumor samples and cells. Additionally, its overexpression restricted the oncogenic properties of RB cells in vitro. Moreover, hsa_circ_0078136 overexpression lowered the protein levels of cytokine ligand molecules of IL-17 signaling pathway in RB cell lines. In vivo, hsa_circ_0078136 overexpression in subcutaneous tumor xenografts reduced tumor growth. We also observed that EIF4A3 binds to the downstream flanking sequence of hsa_circ_0078136 in the SHRPH pre-mRNA transcript, and EIF4A3 overexpression reduced hsa_circ_0078136 expression, suggesting that EIF4A3 inhibited hsa_circ_0078136 formation.

CONCLUSIONS

Our results demonstrate that hsa_circ_0078136 is regulated by EIF4A3 and functions as a tumor suppressor via the IL-17 signaling pathway in RB.

Retinoblastoma: An update on genetic origin, classification, conventional to next-generation treatment strategies

The most prevalent paediatric vision-threatening medical condition, retinoblastoma (RB), has been a global concern for a long time. Several conventional therapies, such as systemic chemotherapy and focal therapy, have been used for curative purposes; however, the search for tumour eradication with the least impact on surrounding tissues is still ongoing. This review focuses on the genetic origin, classification, conventional treatment modalities, and their combination with nano-scale delivery systems for active tumour targeting. In addition, the review also delves into ongoing clinical trials and patents, as well as emerging therapies such as gene therapy and immunotherapy for the treatment of RB. Understanding the role of genetics in the development of RB has refined its treatment strategy according to the genetic type. New approaches such as nanostructured drug delivery systems, galenic preparations, nutlin-3a, histone deacetylase inhibitors, N-MYC inhibitors, pentoxifylline, immunotherapy, gene therapy, etc. discussed in this review, have the potential to circumvent the limitations of conventional therapies and improve treatment outcomes for RB. In summary, this review highlights the importance and need for novel approaches as alternative therapies that would ultimately displace the shortcomings associated with conventional therapies and reduce the enucleation rate, thereby preserving global vision in the affected paediatric population.

Molecular Biomarkers Detected Using Fluorescence in situ Hybridization in a Filipino with Retinoblastoma

Background and Objective

Retinoblastoma is one of the most common intraocular cancers among children usually caused by the loss of retinoblastoma protein function. Despite being a highly heritable disease, conventional diagnostic and prognostic methods depend on clinical examination, with limited consideration of cancer genetics in the standard of care. CD133, KRT19, and MUC1 are commonly explored genes for their utility in liquid biopsies of cancer including lung adenocarcinoma. To date, there are few extensive molecular studies on retinoblastoma in Filipino patients. To this end, the study aimed to describe the copy number of CD133, KRT19, and MUC1 in retinoblastoma samples from a Filipino patient and quantitate the respective expression level of these genes.

Methods

Hematoxylin & Eosin (H&E) staining was utilized to characterize the retinoblastoma tissue while fluorescence in situ hybridization (FISH) using probes specific to CD133, KRT19, and MUC1 was performed to determine the copy number of genes in retinoblastoma samples from a Filipino patient (n = 1). The gene expression of CD133, MUC1, and KRT19 was quantitated using RT-qPCR.

Results

The H&E staining in the retinoblastoma tissue shows poorly differentiated cells with prominent basophilic nuclei. CD133 was approximately 1.5-fold overexpressed in the retinoblastoma tissue with respect to the normal tissue, while MUC1 and KRT19 are only slightly expressed. Multiple intense signals of each probe were localized in the same nuclear areas throughout the retinoblastoma tissue, with high background noise.

Conclusion

These findings suggest that CD133 is a potential biomarker for the staging and diagnosis of retinoblastoma in Filipino cancer patients. However, further optimization of the hybridization procedures is recommended.

Retinoblastoma - A comprehensive review, update and recent advances

Retinoblastoma is the most common pediatric ocular malignancy. It is triggered by a biallelic mutation in the RB1 gene or MYCN oncogene amplification. Retinoblastomas can be unilateral (60%-70%) or bilateral (30%-40%); bilateral tumors are always heritable and present at an earlier age as compared to unilateral ones (18-24 months vs. 36 months in India). High prevalence rates, delayed presentation, and inaccessibility to healthcare lead to worse outcomes in developing countries. The past few decades have seen a paradigm change in the treatment of retinoblastomas, shifting from enucleation and external beam radiotherapy to less aggressive modalities for eye salvage. Multimodality treatment is now the standard of care and includes intraarterial or intravenous chemotherapy along with focal consolidation therapies such as transpupillary thermotherapy, cryotherapy, and laser photocoagulation. Intravitreal and intracameral chemotherapy can help in controlling intraocular seeds. Advanced extraocular or metastatic tumors still have a poor prognosis. Genetic testing, counseling, and screening of at-risk family members must be incorporated as essential parts of management. A better understanding of the genetics and molecular basis of retinoblastoma has opened up the path for potential targeted therapy in the future. Novel recent advances such as liquid biopsy, prenatal diagnosis, prognostic biomarkers, tylectomy, and chemoplaque point to promising future directions.

Updated retinoblastoma incidence and outcome in children in Taiwan from 1980 to 2019: a 40-year nationwide study

BACKGROUND

Retinoblastoma is a potentially fatal disease, and its incidence and mortality varies among different countries and periods.

METHODS

This is a nationwide population-based retrospective study from January 1980 to December 2019 in Taiwan. Patients diagnosed as retinoblastoma were identified from the Taiwan National Cancer Registry. To update the literature on retinoblastoma incidence, mortality and trends in Taiwan, we analysed changes in incidence and survival rates over time according to sex, diagnostic age, laterality and treatment.

RESULTS

During 1980-2019, the incidence of retinoblastoma in Taiwan was 1 per 16 489 live births (95% CI: 13 415-19 564). The diagnostic age decreased from 2.21 ± 0.26 during 1980-1984 to 1.24 ± 0.26 during 1985-2019. Compared with that observed during 1980-1989, the incidence rate observed after 1990 increased significantly in children aged <10 years (RR: 1.62-2.40, P = 0.0049 to < 0.0001). From 1980 to 2019, the incidence rate for the 0-4-year age group increased and that for the 5-9-year age group remained constant. The mean diagnostic age for bilateral retinoblastoma (0.36 ± 0.47 years) was significantly less than that for unilateral retinoblastoma (1.37 ± 0.35 years) during 2007-2019 (P < 0.0001). The 10-year survival rate was highest in the enucleation group (89.8%) compared with radiotherapy (52.2%) and others (70.0%; P < 0.0001).

CONCLUSIONS

During 1980-2019 in Taiwan, the incidence of retinoblastoma increased significantly, and the diagnostic age decreased, which are similar to the ones from other developed countries. However, the survival rate was still lower than that of most developed countries.

Deciphering metabolic heterogeneity in retinoblastoma unravels the role of monocarboxylate transporter 1 in tumor progression

BACKGROUND

Tumors exhibit metabolic heterogeneity, influencing cancer progression. However, understanding metabolic diversity in retinoblastoma (RB), the primary intraocular malignancy in children, remains limited.

METHODS

The metabolic landscape of RB was constructed based on single-cell transcriptomic sequencing from 11 RB and 5 retina samples. Various analyses were conducted, including assessing overall metabolic activity, metabolic heterogeneity, and the correlation between hypoxia and metabolic pathways. Additionally, the expression pattern of the monocarboxylate transporter (MCT) family in different cell clusters was examined. Validation assays of MCT1 expression and function in RB cell lines were performed. The therapeutic potential of targeting MCT1 was evaluated using an orthotopic xenograft model. A cohort of 47 RB patients was analyzed to evaluate the relationship between MCT1 expression and tumor invasion.

RESULTS

Distinct metabolic patterns in RB cells, notably increased glycolysis, were identified. This metabolic heterogeneity correlated closely with hypoxia. MCT1 emerged as the primary monocarboxylate transporter in RB cells. Disrupting MCT1 altered cell viability and energy metabolism. In vivo studies using the MCT1 inhibitor AZD3965 effectively suppressed RB tumor growth. Additionally, a correlation between MCT1 expression and optic nerve invasion in RB samples suggested prognostic implications.

CONCLUSIONS

This study enhances our understanding of RB metabolic characteristics at the single-cell level, highlighting the significance of MCT1 in RB pathogenesis. Targeting MCT1 holds promise as a therapeutic strategy for combating RB, with potential prognostic implications.

Intravitreal Topotecan for Vitreous Seeds in Retinoblastoma: A Long-term Review of 91 Eyes

PURPOSE

To study the long-term efficacy of intravitreal topotecan (IVT) for vitreous seeds in eyes with retinoblastoma and risk factors for their recurrence.

DESIGN

Retrospective, non-comparative, interventional study.

PARTICIPANTS

Ninety-one eyes of 90 patients with retinoblastoma treated between January 2013 and April 2019.

METHODS

Patients with recurrent or refractory vitreous seeds after completion of intravenous or intra-arterial chemotherapy were treated with IVT (30 μg/0.15 ml) by the safety-enhanced technique. The injection was repeated every 4 weeks until the regression of seeds. Patients with a minimum follow-up of 12 months were included in the analysis.

MAIN OUTCOME MEASURES

Primary outcome measures were vitreous seed regression and eye salvage. Secondary outcomes were risk factors for vitreous seed recurrence after treatment with IVT, vision salvage, and complications of IVT.

RESULTS

The median age of the patients was 18 months, with most having group D (n = 58 [64%]) and group E (n = 26 [29%]) retinoblastoma. Vitreous seeds were refractory in 46 eyes (51%) and recurrent in 45 eyes (49%). A total of 317 IVT injections were administered, with the median being 3 injections. The median number of IVT injections required was 2.5 injections for dust, 3 injections for sphere, and 5 injections for cloud morphologic features. Recurrence of vitreous seeds after IVT was seen in 17 eyes (19%) at a mean follow-up of 7.9 months. At a mean follow-up 34 months, vitreous seed regression was achieved in 88 eyes (97%) and eye salvage was achieved in 77 eyes (85%). Older age (P = 0.018) and recurrence of retinal tumor (15/17 eyes; P < 0.01) significantly increased the risk of vitreous seed recurrence. Cataract was the most common complication seen in 17 eyes (9%).

CONCLUSIONS

Intravitreal topotecan at an every 3- to 4-week regimen is effective against both refractory and recurrent vitreous seeds. The vitreous seed morphologic features correspond to the number of injections required for regression. Increasing age and recurrence of retinal tumor increase the risk of vitreous seed recurrence after treatment with IVT.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Evidence in Focus: The Sparse Landscape of Randomized Trials on Retinoblastoma Treatment

Background

Retinoblastoma, although rare, is one of the most common intraocular malignancies worldwide. Its prognosis has improved significantly in the past few decades, thanks to modern treatments, like systemic, intra-arterial, and intravitreal chemotherapy. However, regarding survival, there are significant differences between high- and low-income countries, eye salvage is still a challenge worldwide, and treatment-related toxicity needs to be carefully and sufficiently managed.

Summary

To appraise the strength of supporting evidence, we performed a systematic review of randomized controlled trials investigating any therapeutic protocol for retinoblastoma. Four trials with 174 participants (188 eyes) were eligible, all pertaining to different intravenous chemotherapy regimens. Vincristine, etoposide, and carboplatin (VEC) appear superior to a 5-drug combination for stage III retinoblastoma. Moreover, etoposide and carboplatin as neoadjuvant chemotherapy followed by thermochemotherapy seem to offer better local control than vincristine and carboplatin. However, increasing carboplatin dose in the VEC protocol failed to improve treatment efficacy.

Key Messages

Retinoblastoma is a success story of modern medicine. However, only intravenous chemotherapy has been studied through randomized trials, while evidence for the most novel retinoblastoma treatments has mainly stemmed from observational studies. International collaborations for multicenter randomized trials could overcome difficulties and increase certainty and precision in the field.

Advanced Interventional Treatments in Retinoblastoma Management: A Comprehensive Review

Retinoblastoma is the most common eye malignancy in children that if left untreated can invade intraocular structures, metastasize, and rarely lead to death. Traditionally treated with systemic chemotherapy, Intra-arterial chemotherapy is gaining popularity as it allows for the direct administration of chemotherapy through the ophthalmic artery, thus reducing systemic side effects. Intra-arterial chemotherapy procedures have evolved, with refinements to reduce risks and radiation exposure. Intra-arterial chemotherapy boasts an impressive technical success rate and one year ocular survival even amongst advanced cases. This review offers a thorough examination of the technique, indications, contraindications, outcomes, and alternative options for Intra-arterial chemotherapy.

Incidence Trends, Clinicopathologic Characteristics, and Overall Survival Prediction in Retinoblastoma Children: SEER Prognostic Nomogram Analysis

BACKGROUND

Retinoblastoma is the most common intraocular malignant tumor occurring among children, with an incidence rate of 1/15 000. This study built a joinpoint regression model to assess the incidence trend of retinoblastoma from 2004 to 2015 and constructed a nomogram to predict the overall survival (OS) in children.

MATERIALS AND METHODS

Patients less than 19 years diagnosed with retinoblastoma from 2004 to 2015 were selected from the SEER database. Joinpoint regression analysis (version 4.9.0.0) was performed to evaluate the trends in retinoblastoma incidence rates from 2004 to 2015. Cox Regression Analysis was applied to investigate prognostic risk factors that influence OS.

RESULTS

Joinpoint regression revealed that retinoblastoma incidence exhibited no significant increase or decrease from 2004 to 2015. As per the multiple Cox regression, tumor size, laterality, and residence (rural-urban continuum code) were correlated with OS and were used to construct a nomogram. The nomogram exhibited a good C-index of 0.71 (95% CI, 0.63 to 0.79), and the calibration curve for survival probability demonstrated that the predictions corresponded well with actual observations.

CONCLUSIONS AND RELEVANCE

A prognostic nomogram integrating the risk factors for retinoblastoma was constructed to provide comparatively accurate individual survival predictions. If validated, this type of assessment could be used to guide therapy in patients with retinoblastoma.

Advancements in Retinoblastoma Treatment: Unraveling the Potential of Intravitreal Chemotherapy

Retinoblastoma necessitates urgent attention due to its potential fatality if untreated. Multiple treatment options are available and should be employed according to size, location, and the extent of dissemination. This review emphasizes the need for increased awareness, advanced diagnostic tools, and innovative treatment approaches, especially intravitreal chemotherapy (IVitC) to address the diverse manifestations and aggressive nature of retinoblastoma. Timely diagnosis and commitment to treatment are pivotal, as delays and reluctance to undergo enucleation contribute to unfavorable outcomes. The evolving treatment landscape, spanning from traditional interventions to modern targeted therapies such as intravitreal melphalan, holds promise for improved outcomes. While the intravitreal approach presents challenges, ongoing research aims to establish its definitive role in retinoblastoma treatment. In the treatment of retinoblastoma, IVitC raises considerations about side effects. The risk of tumor spread beyond the eye is rare, emphasising the potential of IVitC in carefully selected cases. Intravitreal injections exhibit fewer local adverse effects compared to intra-arterial chemotherapy, with careful measures reducing significant ocular complications. The evaluation of ocular toxicity, particularly with melphalan, underscores the importance of a nuanced approach to achieve the right balance between therapeutic efficacy and ocular safety. This comprehensive analysis of studies on IVitC and its ocular and systemic complications provides valuable insights for enhanced patient care. The review concludes with a focus on balancing safety and efficacy in local chemotherapeutic drugs, highlighting the need for thoughtful measures and continued research to optimise treatment modalities globally.

Advanced Technologies of Drug Delivery to the Posterior Eye Segment Targeting Angiogenesis and Ocular Cancer

Retinoblastoma (RB), a childhood retinal cancer is caused due to RB1 gene mutation which affects the child below 5 years of age. Angiogenesis has been proven its role in RB metastasis due to the presence of vascular endothelial growth factor (VEGF) in RB cells. Therefore, exploring angiogenic pathway by inhibiting VEGF in treating RB would pave the way for future treatment. In preclinical studies, anti-VEGF molecule have shown their efficacy in treating RB. However, treatment requires recurrent intra-vitreal injections causing various side effects along with patient nonadherence. As a result, delivery of anti-VEGF agent to retina requires an ocular delivery system that can transport it in a non-invasive manner to achieve patient compliance. Moreover, development of these type of systems are challenging due to the complicated physiological barriers of eye. Adopting a non-invasive or minimally invasive approach for delivery of anti-VEGF agents would not only address the bioavailability issues but also improve patient adherence to therapy overcoming the side effects associated with invasive approach. The present review focuses on the eye cancer, angiogenesis and various novel ocular drug delivery systems that can facilitate inhibition of VEGF in the posterior eye segment by overcoming the eye barriers.

Conservative treatment using laser diode and systemic chemotherapy for early-stage bilateral retinoblastoma: A 14-year prospective cohort study

BACKGROUND

Solid evidence of the safety and effectiveness of retinoblastoma (RB) conservative treatment using thermotherapy and systemic chemotherapy with long-term follow-up is scarce, especially in low-resource countries.

AIMS

This study examined the outcomes of this treatment and associated predictors in Vietnam to strengthen the current RB treatment protocol focusing on preserving eye and vision in low-resource settings.

METHODS AND RESULTS

A prospective cohort study was conducted at Ho Chi Minh City Eye Hospital in Vietnam from 2005 to 2019. All eligible patients with bilateral RB (one eye already removed and another eye classified as group A or B) and without previous treatment were recruited. All patients received thermotherapy and six cycles of systemic three-agent chemotherapy repeated every 4 weeks. A standardized questionnaire was used to collect information on study participants' age, symptoms, tumor characteristics, treatment, and outcomes. Among 50 eyes of all 50 patients with a median age of 9 (4-20) months, 34 eyes were in group B (68%). The median follow-up time was 60 (60-84) months. All 139 preserved tumors regressed mostly to type 4 (70.4%) and type 3 (23.7%) scars. Kaplan-Meier analysis found the overall globe-salvage rate at 5 years of 91.9% (95% CI: 80.1%-97.7%). Most eyes (41/50, 82%, 95% CI: 69.2%-90.2%) had a final visual acuity ≥0.1. The visual acuity is higher when tumors regressed to a type 4 scar (p = .007, AOR = 8.098, 95% CI: 1.79-36.53) which also shows less enucleation than a type 3 scar (p = .002, AOR = 0.06, 95% CI: 0.01-0.37%). Gender effect on visual acuity after treatment was significant and may be due to discrimination. No major complications were recorded.

CONCLUSION

Conservative treatment of early-stage RB is safe and effective. Long-term, thorough follow-ups of patients post-treatment are needed. The regression patterns of scars could be a useful indicator of treatment failure.

Likelihood of germline mutation with solitary retinoblastoma based on tumour location at presentation

BACKGROUND/AIMS

To evaluate the likelihood of germline mutation in patients presenting with solitary retinoblastoma based on tumour location at first examination.

METHODS

Retrospective analysis of solitary unilateral retinoblastoma for likelihood of germline mutation (family history of retinoblastoma and/or genetic testing indicating germline RB1 mutation and/or development of additional new or bilateral tumours) based on tumur location at presentation (macular vs extramacular).

RESULTS

Of 480 consecutive patients with solitary retinoblastoma, 85 were in the macula (18%) and 395 were extramacular (82%). By comparison (macular vs extramacular tumours), macular tumours had smaller basal diameter (12.7 mm vs 18.9 mm, p<0.001) and smaller tumour thickness (6.1 mm vs 10.7 mm, p<0.001). Patients with macular tumours demonstrated greater likelihood for germline mutation (23% vs 12%, OR=2.18, p=0.011), specifically based on family history of retinoblastoma (13% vs 2%, OR=4.64, p=0.004), genetic testing showing germline RB1 mutation (27% vs 15%, OR=2.04 (95% CI 1.04 to 4.01), p=0.039), development of new tumours (13% vs 3%, OR=5.16 (95% CI 2.06 to 12.87), p=0.001) and/or development of bilateral disease (9% vs 2%, OR=4.98 (95% CI 1.70 to 14.65), p=0.004).

CONCLUSIONS

Among patients with solitary unilateral retinoblastoma, those presenting with macular tumour (compared with extramacular tumour) show 2.18 times greater likelihood for germline mutation and an even higher likelihood of development of subsequent tumours. Solitary macular retinoblastoma should raise an index of suspicion for likely germline mutation and multifocal disease.

MRI features for prediction of the intravenous chemotherapy effect in patients with retinoblastoma

AIM

To investigate the value of orbital magnetic resonance imaging (MRI) features in predicting the efficacy of intravenous chemotherapy (IVC) for patients with retinoblastoma (RB).

MATERIALS AND METHODS

The pretreatment clinical and MRI data of 100 eyes from 80 RB patients who underwent IVC were collected retrospectively. There were 59 eyes in the effective group and 41 eyes in the ineffective group, and the baseline data of the two groups were compared statistically. Three radiologists reviewed and evaluated each lesion independently based on 25 MRI features. The predictive values of the MRI features for IVC efficacy were assessed by multi-factor logistic regression analysis, and their odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Receiver operating characteristic curves (ROCs) with the area under the curve (AUC) were used to determine the predictive abilities. A predictive model was constructed by integrating all independent predictors visualised by the nomogram.

RESULTS

There were no statistically significant differences in sex or age between the effective and ineffective groups. The results of multivariate regression analysis showed that laterality, margin, and anterior eye segment enhancement were identified as independent factors that could predict IVC efficacy. The predictive model combining these three features was constructed, and it had an AUC of 0.732 (95% CI: 0.633, 0.831, p<0.01), a sensitivity of 71.2%, and a specificity of 70.7%.

CONCLUSION

The data demonstrate that the orbital MRI features can be used to predict IVC efficiency before RB patients are treated.

Ocular Survival Following Intravitreal Melphalan as Adjuvant Treatment for Vitreous Retinoblastoma Seeding

Purpose

To evaluate the efficacy of intravitreal chemotherapy for vitreous seeding in patients with retinoblastoma (Rb).

Design

Retrospective, single-arm cohort study.

Methods

This study was conducted at a tertiary eye center. Between 2013 and 2021, 27 patients (27 eyes) with vitreous Rb receiving adjuvant intravitreal melphalan (IVM) as secondary/salvage treatment in one eye were included. Patients who were unable to follow-up or treated elsewhere were excluded. Survival analysis was performed to assess the incidence of enucleation in the melphalan-treated group, as well as in bilateral cases with eyes receiving melphalan and those receiving standard treatment, consisting of chemotherapy, thermotherapy, and enucleation according to the disease stage.

Results

The median (interquartile range) follow-up time was 65 months (range, 34-83 months). Seventeen patients (63%) had bilateral disease. Sixteen eyes (59%) were saved. The Kaplan-Meier survival estimates for eyes receiving melphalan were 100% at 1 year (95% confidence interval [CI]:11.2-14.3), 75% (95% CI:14.2-48.9) at 3 years, and 50% at 5 years. Melphalan-treated patients with bilateral disease showed a significantly higher number of saved eyes than the standard treatment group (P=0.002). Tumor recurrence was the primary cause of enucleation, accounting for 36% of the cases. In the vitreous hemorrhage group, the odds of enucleation were 13 times higher (95% CI:1.04-165.28) than in the group without this condition.

Conclusion

IVM is an effective treatment option for vitreous seeds. After 3 years of follow-up, the estimated survival rate for saved eyes decreased, and vitreous hemorrhage significantly increased the likelihood of enucleation. Further studies are required to determine the precise effects of IVM.

Clinical characteristics, treatment and prognosis of infants with retinoblastoma: a multicenter, 10-year retrospective analysis

BACKGROUND

To summarize the characteristics and treatment, and analyze the prognosis of large number of infants with retinoblastoma (RB) in China through a multicenter, 10-year retrospective analysis.

METHODS

The data of RB infants were collected from multiple centers. The characteristics and survival prognosis were analyzed. The overall survival (OS) rate was estimated by the Kaplan-Meier method. Multivariate Cox survival analysis was to evaluate the independent risk factors affecting the prognosis of RB infants.

RESULTS

A total of 373 RB infants (202 boys and 171 girls) were included, the median age was 6.22 months (10 days to 11.93 months). The median follow-up time of RB infants was 18.4 (1.02-122.81 months). After excluding the lost to follow-up cases, the OS rate was 97.7% (345/353). Kaplan-Meier survival analysis indicated that 9 cases died and the median survival time was not reached. Univariate analysis of prognostic factors revealed eye affected, presenting signs, left eye stage and recurrence to be poor prognostic factors for OS rate in RB infants (all P < 0.05). Multivariate Cox regression analyses for OS showed recurrence (HR = 1.376, 95% CI: 0.878-2.156, P = 0.048) was an independent factor for prognosis of infants with RB. The median survival time of infants underwent chemotherapy + intra-arterial chemotherapy (IAC) + enucleation + vitrectomy was the longest than other treatments (n = 9, 47.64 months, OS = 100%, all P < 0.05). There was a history of RB in 17 infants' lineal relatives. Kaplan-merier survival analysis indicated 1 case died and the median survival time was not reached.

CONCLUSION

Recurrence is an independent factor for prognosis of RB infants, which still needs attention after treatment. Early screening, comprehensive treatments and follow-up of patients may lead to improvements of prognosis of RB infants.

Polyester 5-0 suture for porous implant placement after retinoblastoma enucleation: analysis of 120 sockets

BACKGROUND

Techniques used to suture the rectus muscle to the implant can influence the implant-related complications which is still a major problem following retinoblastoma enucleation. The goals of this work were to report the efficacy among patients with retinoblastoma who underwent enucleation followed by porous implant placement with the rectus muscles sutured with 5-0 polyester suture.

METHODS

This was a retrospective study of consecutive patients with retinoblastoma who underwent primary enucleation and porous implant placement with the rectus muscles tagged and sutured to the implant with polyester 5-0 suture. All the patients were followed up for a minimum of 2 years. The main outcome measure was implant exposure. The secondary efficacy measures were other implant-related complications.

RESULTS

Between May 2016 and December 2018, a total of 120 patients (120 eyes) underwent primary enucleation and porous implant placement were included. Postoperatively, 10/120 (8.3%) eyes developed exposure or conjunctival granuloma. Exposure was the most common postoperative complication (7/10, 70.0%). There were no cases of implant extrusion, migration, or infection.

CONCLUSIONS

Polyester 5-0 sutures are successful in patients with retinoblastoma who underwent enucleation followed by porous implant placement. Complications are minimal. Polyester 5-0 sutures were not associated with unacceptable complications in this pediatric population.

PRMT5 promotes retinoblastoma development

Epigenetic mechanism, including DNA methylation and histone modifications, contributes to alterations in the expression patterns of genes regulating malignant phenotype of cancer cells. However, the epigenetic modulation of vascular endothelial growth factor-A (VEGFA) in retinoblastoma (RB) has not been clearly established. We aimed to examine the epigenetic regulation of VEGFA by protein arginine methyltransferase 5 (PRMT5) in RB. Using the GEO database, we identified VEGFA as a pathogenic gene in RB. Silencing of VEGFA in SO-RB50 and Y79 cells inhibited cell proliferation, angiogenesis, and migration, promoted apoptosis, and suppressed tumor growth in mice. Mechanistically, PRMT5 promoted H3K4me3 modification of the VEGFA promoter, thereby activating VEGFA expression. VEGFA could regulate the expression of MMP1, MMP2, and MMP9. Further silencing of VEGFA in RB cells overexpressing PRMT5 constrained the expression of MMP1, MMP2 and MMP9, and suppressed the growth of tumors in mice. In conclusion, this study clarifies that the depletion of PRMT5 reduces H3K4me3-mediated VEGFA transcription and retards the carcinogenesis of RB by suppressing the expression of MMPs.

Highly Efficient Photodynamic Therapy with Mitochondria-Targeting Aggregation-Induced Emission Photosensitizer for Retinoblastoma

Retinoblastoma (RB) is an aggressive eye cancer in infancy and childhood, lethal by metastasis if left untreated. Currently, the survival rate and the chance of saving vision depend on the severity of the disease. In this work, a highly efficient photodynamic ophthalmic therapy for RB is reported by employing an isoquinolinium-based aggregation-induced-emission (AIE) photosensitizer (PS) TPE-IQ-2O for photodynamic inactivation (PDI). TPE-IQ-2O is an efficient mitochondria-targeting photosensitizer as an efficient guided photodynamic therapy (PDT) agent against cancer cells. Maximizing cancer-selectively damage to tumors with minimized side effects on normal tissue is essential for effective anticancer PDT and provides long-lasting protection against metastasis. In addition, TPE-IQ-2O can effectively reduce the degree of tissue inflammation by inhibiting the expression of related inflammatory factors. TPE-IQ-2O also exhibits excellent biocompatibility with a neglectable hemolysis effect on mouse red blood cells and almost no killing effect on mammalian cells, which enables its potential applications in the treatment of RB.

The Antitumor Effect of Topotecan Loaded Thiolated Chitosan-Dextran Nanoparticles for Intravitreal Chemotherapy: A Xenograft Retinoblastoma Model

Purpose

This research intended to fabricate the thiolated chitosan-dextran nanoparticles (NPs) containing topotecan (TPH-CMD-TCS-NPs) to assess the ability of NPs in improving the efficacy of intravitreal chemotherapy of retinoblastoma in a rabbit xenograft model.

Methods

The coacervation process was used to produce the NPs. The cellular uptake of Cyanine-3 (CY3)-labeled NPs were investigated in human retinoblastoma Y79 cells using confocal microscopy. Also, the prepared TPH-CMD-TCS-NPs were tested in vitro by the tetrazolium dyes II (XTT) and flow cytometry in order to assess their cytotoxicity. In addition, a rabbit xenograft model of retinoblastoma was developed to test the antitumor effectiveness of TPH-CMD-TCS-NPs through intravitreal administration.

Results

NPs had a mean diameter, polydispersity index, and zeta potential of 30 ± 4 nm, 0.24 ± 0.03 and +10 ± 3 mV, respectively. NPs (IC50s 40.40 compared to 126.20 nM, P = 0.022) were more effective than free topotecan as a dose-based feature. The tumor reaction to intravitreal chemotherapy with NPs was measured by evaluating the percentage of necrosis in the tumor tissue (91 ± 2%) and vitreous seeds (89 ± 9%) through hematoxylin and eosin (H&E) staining. In comparison with the control group, the TPH-CMD-TCs-NPs treated group showed a significant decrease in tumor volume seven days after the intravitreal injection (P = 0.039). No significant changes were found in the ERG parameters after the intravitreal injection of TPH-CMD-TCs-NPs or TPH (P > 0.05).

Conclusion

This investigation revealed definitive antitumor efficacy of TPH-CMD-TCS-NPs by intravitreal administration in the rabbit xenograft retinoblastoma model.

Changing trends in pseudoretinoblastoma diagnoses: A 10 year review from the United Kingdom

AIM

To study the different types and frequency of pseudoretinoblastoma (pseudoRB) lesions who present to a retinoblastoma centre due to concern that the condition may be retinoblastoma.

METHODS

A retrospective chart review of 341 patients presenting sporadically to the Royal London Hospital from January 2009 to December 2018.

RESULTS

220 patients (65%) were confirmed to have retinoblastoma, while 121 (35%) had pseudoRB. There were 23 differential diagnoses in total. The top 3 differential diagnoses were Coats' disease (34%), Persistent Foetal Vasculature (PFV) (17%) and Combined Hamartoma of Retina and Retinal Pigment Epithelium (CHR-RPE) (13%). PseudoRBs differed with age at presentation. Under the age of 1 (n = 42), the most likely pseudoRB conditions were PFV (36%), Coats' disease (17%) and CHR-RPE (12%). These conditions were also the most common simulating conditions between the ages of 1 and 2 (n = 21), but Coats' disease was the most common in this age group (52%), followed by CHR-RPE (19%) and PFV (14%). Between the ages of 2 and 5 (n = 32), Coats' disease remained the most common (44%) pseudoRB lesion followed by CHR-RPE (13%), or PFV, Retinal Astrocytic Hamartoma (RAH), familial exudative vitreoretinopathy (FEVR) (all 6.3%). Over the age of 5 (n = 26), pseudoRBs were most likely to be Coats' disease (35%), RAH (12%), Uveitis, CHR-RPE, FEVR (all 7.7%).

CONCLUSION

35% of suspected retinoblastoma cases are pseudoRB conditions. Overall, Coats' disease is the most common pseudoRB condition, followed by PFV. Hamartomas (CHR-RPE & RAH) are more prevalent in this cohort, reflecting improvements in diagnostic accuracy from referring ophthalmologists.

Retinoblastoma: Review and new insights

Retinoblastoma (Rb), the most frequent malignant intraocular tumor in childhood, is caused by mutations in the retinoblastoma gene (RB1) situated on chromosome 13q14.2. The incidence of retinoblastoma is approximately 1 in 17,000 live births with approximately 8,000 new cases diagnosed each year worldwide. Rb is the prototypical hereditary cancer in humans. Autosomal dominant inheritance is seen in 30-40% of cases whereas the non-inherited sporadic type accounts for the remaining 60-70%. Rb arises due to inactivation of both alleles of the Rb tumor suppressor gene, which results in a defective Rb protein (pRB) with subsequent cell cycle impairment and uncontrolled cell proliferation. Patients with Rb have survival rates higher than 95-98% in industrialized countries but mortality remains high in developing countries. For example, the mortality rate in Africa is 70%. In all cases of intraocular and extraocular retinoblastoma, there is a need for new therapies that are more effective and carry less risk of toxicity. The Bruckner test is a practical and easy test for the detection of Rb, this test consists of assessing the fundus reflex through the pupil (red reflex) in both eyes simultaneously with a bright coaxial light produced with the direct ophthalmoscope. Rb can be detected by the Bruckner test showing a pupil that shines white or “Leukocoria”. Although the diagnosis of Rb remains essentially clinical, the newly identified biomarkers could contribute to early molecular detection, timely detection of micrometastases and establish new therapeutic options for Rb.

Anemia and Bone Marrow Suppression After Intra-Arterial Chemotherapy in Children With Retinoblastoma: A Retrospective Analysis

Background

Retinoblastoma (Rb) is a common ocular malignant tumor in children. Intra-arterial chemotherapy (IAC) has been widely used in children with Rb and has achieved an ideal therapeutic effect. However, IAC has side effects, including anemia and bone marrow suppression, for which explicit evidence on the risk factors is lacking. This study aimed to evaluate the covariates that may affect the occurrence of anemia and bone marrow suppression in children with Rb after IAC.

Methods

Children with Rb admitted between May 2019 and January 2021 were included into the study. The differences in the number of children with anemia and bone marrow suppression before and after IAC according to different covariates were recorded. All potential impact factors were included into the univariate and multivariate regression models to identify the related covariates of post-IAC anemia and bone marrow suppression.

Results

Data of 282 children with Rb were retrospectively collected. After IAC, children with Rb had increased severities of anemia (p <0.0001, chi-square test) and bone marrow suppression (p = 0.001, chi-square test). Moreover, the number of children with Rb who had an increased cross-level change in the severity of anemia and degree of bone marrow suppression was 80 (41.24%) and 64 (32.49%), respectively. The univariate regression analysis showed that numerous factors (such as pre-IAC intravenous chemotherapy, results of pre-IAC routine blood tests, and some serological indicators for liver and kidney function) affected the anemia severity and degree of bone marrow suppression in children with Rb after IAC. Additionally, the predictive model of the multivariate regression could predict anemia and bone marrow suppression.

Conclusion

Children with Rb may have an increased risk of anemia and bone marrow suppression after IAC, but this is temporary and can be influenced by several factors. Therefore, IAC should be maintained as the standard of care. We generated predictive equations for predicting anemia severity and degree of bone marrow suppression, which can guide the prediction and timely control of anemia and bone marrow suppression after IAC.

Ruptured retinoblastoma: management in a rare case scenario

A preschool child presented with white reflex in left eye since 2 months. Examination under anaesthesia revealed left eye retinoblastoma group D as per international classification of retinoblastoma. In collaboration with medical oncologist, systemic chemotherapy was started. After two cycles of systemic chemotherapy, tumour ruptured into the vitreous cavity suspending the tumour cells in the vitreous jelly. After a combination of systemic and intravitreal chemotherapy with adjuvant transpupillary thermotherapy of the residual retinal tumour, retinoblastoma regressed completely with corresponding flat scar.

Chronic myelogenous leukemia in a child following treatment for bilateral retinoblastoma

A 3-year-old child was incidentally found to have chronic myelogenous leukemia (CML) during an admission for a routine ophthalmic examination under anesthesia. The child had received systemic chemotherapy and focal treatment for Groups C and D retinoblastoma in the right and left eye, respectively, when she was 7 months old. CML was treated with dasatinib, and the child attained a major molecular response. The child is now 3 years after treatment of CML, and the retinoblastoma remains inactive. CML following treatment of retinoblastoma is a rare occurrence. Long term and close monitoring of retinoblastoma patients who received systemic chemotherapy using serial blood tests is essential.

SOX2 maintains the stemness of retinoblastoma stem-like cells through Hippo/YAP signaling pathway

PURPOSE

To explore the mechanisms underlying stemness maintenance of retinoblastoma (RB) stem cells (RSCs).

METHODS

The retinoblastoma stem-like cells (RSLCs) were isolated by single cell cloning in combination of examination of sphere-forming capacities. The stemness of the cells were characterized by the sphere-forming capacity and the expression levels of RSCs markers. Gene manipulation was performed by lentivirus system. Transcriptional regulation was identified by qRT-PCR, luciferase reporter, nuclear run-on and DNA pull-down assay. Spearman analysis was employed for correlation analysis of genes in tumor tissues of RB patients.

RESULTS

The isolated RSLCs exhibited enhanced sphere-forming capacity and constantly higher levels of CD44, ABCG2, SOX2 and PAX6, but not CD133. SOX2 positively regulated the stemness of RSLCs. SOX2 directly binds to the promoters of WWTR1 and YAP and transcriptionally activates WWTR1 and YAP. Knockdown of WWTR1 or YAP partially abolished the effect of SOX2 on the stemness of RSLCs.

CONCLUSIONS

SOX2, as a key deriver, maintains RB stemness by activating Hippo/YAP signaling. Inhibition of Hippo/YAP signaling would be an effective strategy for human RB caused by SOX2 upregulation.

Xanthatin Selectively Targets Retinoblastoma by Inhibiting the PLK1-Mediated Cell Cycle

Purpose

Retinoblastoma is the most common primary intraocular malignant tumor in children. Although intra-arterial chemotherapy and conventional chemotherapy have become promising therapeutic approaches for advanced intraocular retinoblastoma, the side effects threaten health and are unavoidable, making the development of targeted therapy an urgent need. Therefore, we intended to find a potential drug for human retinoblastoma by screening an in-house compound library that included 89 purified and well-characterized natural products.

Methods

We screened a panel of 89 natural products in retinoblastoma cell lines to find the inhibitor. The inhibition of the identified inhibitor xanthatin on cell growth was detected through half-maximal inhibitory concentration (IC50), flow cytometry assay, and zebrafish model system. RNA-seq further selected the target gene PLK1.

Results

We reported the discovery of xanthatin as an effective inhibitor of retinoblastoma. Mechanistically, xanthatin selectively inhibited the proliferation of retinoblastoma cells by inducing cell cycle arrest and promoting apoptosis. Interestingly, xanthatin targeted PLK1-mediated cell cycle progression. The efficacy of xanthatin was further confirmed in zebrafish models.

Conclusions

Collectively, our data suggested that xanthatin significantly inhibited tumor growth in vitro and in vivo, and xanthatin could be a potential drug treatment for retinoblastoma.

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.

Green Light-Triggered Intraocular Drug Release for Intravenous Chemotherapy of Retinoblastoma

Retinoblastoma is one of the most severe ocular diseases, of which current chemotherapy is limited to the repetitive intravitreal injections of chemotherapeutics. Systemic drug administration is a less invasive route; however, it is also less efficient for ocular drug delivery because of the existence of blood-retinal barrier and systemic side effects. Here, a photoresponsive drug release system is reported, which is self-assembled from photocleavable trigonal small molecules, to achieve light-triggered intraocular drug accumulation. After intravenous injection of drug-loaded nanocarriers, green light can trigger the disassembly of the nanocarriers in retinal blood vessels, which leads to intraocular drug release and accumulation to suppress retinoblastoma growth. This proof-of-concept study would advance the development of light-triggered drug release systems for the intravenous treatment of eye diseases.

Ocular safety of repeated intravitreal injections of Carboplatin and Digoxin: A preclinical study on the healthy rabbits

To evaluate the ocular safety of intravitreal carboplatin and digoxin injections as a new intravitreal chemotherapy option for retinoblastoma tumor vitreous seeds. Eighteen rabbits were divided randomly into three groups to receive intravitreal injection of Digoxin (6 rabbits), Carboplatin (7 rabbits), or Saline (5 rabbits). In every group, one eye randomly treated with 10 µg Digoxin in 0.1 cc or 1 µg Carboplatin or Saline, and the contralateral eye was considered as the control. All groups underwent three consecutive injections of the drugs with 1-week intervals. Baseline electroretinography (ERG) was recorded from both eyes of all the animals prior to injection and was repeated 1st day, 1st week, and 1st month after the last injection. All rabbits were sacrificed 1 month after the last injection, and histological studies were done. Mean a and b wave amplitudes decreased significantly at 1st day, 1st week, and 1st month after the last intravitreal injection of 10 µg Digoxin in comparison with other groups (p-value: .02). Contradictory, 1 µg Carboplatin injected eyes had minimal ERG changes. There were some nonspecific ERG changes with unclear clinical significance in non-injected contralateral control eyes of Digoxin and Carboplatin groups in comparison with the control eyes of the Saline group. Histological studies revealed considerable neural retinal atrophy in injected eyes of the Digoxin group. Intravitreal 10 µg Digoxin might have more local ocular toxicity in comparison with intravitreal Carboplatin in albino rabbit eyes. Future studies should assess the induced toxicity of intravitreal injection of these drugs on the non-injected contralateral eye.

Aqueous seeding in intraocular retinoblastoma: A review

The management of retinoblastoma is complex. With increasing treatment modalities and increasing experience with each treatment modality, the globe salvage rates have drastically improved with time. Aqueous seeding in an eye with retinoblastoma is classified as group E based on International Classification of Intraocular Retinoblastoma, and most group E eyes were enucleated a decade earlier. Newer modalities of treatment have improved the globe salvage rates in group E eyes including those with aqueous seeding. Various globe salvage treatment modalities attempted for the management of aqueous seeds include external beam radiotherapy, plaque radiotherapy, intra-arterial chemotherapy, periocular chemotherapy, intravitreal chemotherapy and intracameral chemotherapy. Of all treatment modalities, intracameral chemotherapy holds promise for the management of aqueous seeds in selected patients, but it should be done with the utmost care by a trained ocular oncologist. Enucleation is still the preferred modality of treatment for eyes with advanced retinoblastoma and anterior segment invasion. This review focuses on the current evidence on aqueous seeding, highlighting the pathogenesis, classification, clinical presentation, treatment and outcomes.

Recurrence and new tumor development after frontline intravenous chemotherapy for retinoblastoma: Risk factors and treatment results

PURPOSE

To evaluate the risk factors leading to recurrence and new tumor (NT) development in patients with retinoblastoma after intravenous chemotherapy (IVC) and to review the treatment outcomes.

MATERIALS AND METHODS

The records of 166 retinoblastoma cases (having 246 affected eyes) who underwent six-cycle IVC (vincristine, etoposide, and carboplatin) as primary treatment between October 1999 and August 2020 were reviewed retrospectively.

RESULTS

The mean ages at presentation were 9.0 (median: 8.0) and 9.2 (median: 8.5) months in cases with recurrence and NTs respectively. Recurrence was detected in 40 (16.3%) eyes, NTs in 29 (11.8%), and both recurrence/NTs in 24 (9.8%). The mean time elapsed till recurrence and NT was 10.7 months. Multivariable analysis showed that the factors predictive of recurrence were largest tumor base diameter (LTBD) >12 mm (p = 0.039) and presence of subretinal seeds at diagnosis (p = 0.043). Multivariable risk factors for the development of NTs were bilateral familial retinoblastoma (p = 0.001) and presence of subretinal seeds at diagnosis (p = 0.010). Mean follow-up was 80.1 (median: 72.5) months. By Kaplan-Meier analysis, the 1-, 3-, and 6-year recurrence and NT rates were 21.2%, 28.1%, and 28.7% and 14.9%, 22.6%, and 23.9% respectively. The most common treatment methods used for recurrent and/or NTs included cryotherapy, transpupillary thermotherapy, and intra-arterial chemotherapy. Enucleation was eventually required in 24/93 (25.8%) eyes. No patient developed metastasis.

DISCUSSION

Development of recurrence and/or NT after IVC was noted in 38% of all retinoblastoma eyes. Bilateral familial disease, LTBD >12 mm, and presence of subretinal seeds at baseline were risk factors for recurrence and NTs in this study.

Hydrogel implants for transscleral diffusion delivery of topotecan: In vivo proof of concept in a rabbit eye model

Treatment of retinoblastoma (Rb) has greatly improved in recent years in terms of survival and eye salvage rates, using mainly intra-arterial or intravitreal chemotherapy. However, the treatment of vitreous tumor seeding still represents a challenge and it is of great interest to develop new strategies to deliver pharmacologically sufficient drug amounts to the vitreous humor. In the present work, we present a lens-shaped bi-layered hydrogel implant for delivery of topotecan (TPT) via transscleral diffusion. The implant consists of an inner TPT-loaded poly(2-hydroxyethyl methacrylate) (pHEMA) layer adjacent to the sclera and an outer covering poly(2-ethoxyethyl methacrylate) (pEOEMA) layer impermeable to TPT. TPT-loaded pHEMA samples exhibit long-lasting in vitro cytotoxicity against the Rb cell line Y79. In an in vivo experiment, pHEMA/pEOEMA implants are successfully surgically administered to the posterior segment of rabbit eyes. The determination of TPT pharmacokinetics demonstrates the attainment of promising levels of TPT (10 ng/ml) in vitreous humor 8 h after implant placement. The results from the pilot experiment constitute the proof of principle for the use of the proposed implants as a drug delivery system for the local treatment of intraocular diseases.

Retinoblastoma presenting as pseudohypopyon and preserved visual acuity

Purpose

To describe a Case of retinoblastoma that presented subtly as a pseudohypopyon in a child with preserved visual acuity.

Observations

A 3-year-old male was referred for concern of hypopyon in the left eye. Initial examination revealed 20/30 vision, a pseudohypopyon, and a large white mass on fundoscopy. Examination under anesthesia revealed extensive retinoblastoma with vitreous seeds and anterior chamber involvement. Enucleation was performed and histology demonstrated retinoblastoma with tumor cells found within the ciliary body, iris, iridocorneal angle, and Schlemm canal. Based on the high-risk histopathology findings, adjuvant chemotherapy was performed.

Conclusions and importance

Retinoblastoma is the most common primary intraocular malignancy in children. Though the classic presentation is leukocoria and/or strabismus, it can present in a variety of ways. Physicians should be aware that retinoblastoma, even severe forms, can present subtly with pseudohypopyon and preserved vision. Adjuvant chemotherapy for anterior segment involvement remains controversial.

Clinical outcomes and prognosis of Thai retinoblastoma patients

BACKGROUND

Retinoblastoma (RB) outcomes in Thailand are unfavorable compared to those of developed countries. This study aims to determine whether the clinical outcomes of patients with RB significantly improved after the implementation of new therapeutic approaches and which clinical factors affect survival and globe-saving outcomes.

METHODS

The medical records of patients newly diagnosed with RB and treated at Siriraj Hospital between January 2005 and December 2018 were reviewed retrospectively. Clinical data, treatments, and outcomes were collected and analyzed.

RESULTS

In 194 eyes (144 patients), leukocoria was the most common presenting feature (76.8%); 129 (66.5%) eyes were staged in group E of the International Classification of Intraocular Retinoblastoma. Of the 149 enucleated eyes, 35 had high-risk histopathological features, mostly choroidal invasion; 45 eyes (23.2%) could be salvaged. The 5-year overall survival rate was 90.3%, an improvement compared to the previous study. The 5-year enucleation-free survival rates of Groups A and B, C, D and E were 100%, 83.1%, 36.7% and 16.6% respectively. Factors associated with a lower survival rate were interval from symptom onset to diagnosis >3 months (hazard ratio (HR): 5.8: 95% confidence interval (CI): 1.637, 20.579) and buphthalmos (HR: 12.57: 95% CI: 3.936, 40.153). Factors associated with high-risk features were secondary glaucoma (HR: 11.016: 95% CI: 1.24, 98.10) and pseudohypopyon (HR: 14.110: 95% CI: 2.16, 92.05).

CONCLUSIONS

Survival rates and globe-saving rates appear to have improved; however, advanced-stage presentation remains the major hindrance. Further studies with a larger cohort and longer follow-up are warranted.

Eye Salvage with Intra-Arterial and Intra-Vitreal Chemotherapy in Patients with Retinoblastoma: 8-Year Single-Institution Experience in Colombia

INTRODUCTION

Intra-arterial chemotherapy (IAC) is useful for eye preservation in advanced retinoblastoma (Rb). Intra-vitreal chemotherapy (IvitC) is the latest treatment for vitreous seeds.

METHODS

The present study is a retrospective assessment of 100 eyes, treated with primary or secondary IAC alone or with IvitC. We evaluated demographic and clinical variables, eye salvage, associated adverse events, and patient survival. Data were analyzed using descriptive statistics. Kaplan-Meier survival curves and Cox hazard ratios were utilized to assess the effect of demographic and clinical variables over eye salvage.

RESULTS

Bilateral Rb was observed in 61% of patients, and 57% of eyes received secondary treatment. Forty eyes needed intra-arterial plus IvitC and 62 presented advanced disease (group D and E). Three- and 5-year ocular survival probabilities were 75 and 68%. We found a higher risk in group D and E eyes and those requiring 2 or more routes for ophthalmic artery catheterization. Patients coming from other countries also showed increased risk. Using primary or secondary treatment, or IvitC, did not affect this risk. Overall rates of survival and eye salvages were 98.8 and 73%, and we had a 100% catheterization success and none ophthalmic arterial occlusions.

CONCLUSIONS

In an upper middle-income country such as Colombia, a specialized institution counting with therapeutic alternatives and a multidisciplinary team can reach rates of patient survival and eye salvage similar to those of high-income countries.

Impact of Laterality on Cumulative Survival in Patients Diagnosed with Retinoblastoma: A Retrospective Cohort Analysis of 1925 Cases in the Surveillance, Epidemiology, and End Results (SEER) Program

Background

Retinoblastoma is an intraocular cancer with potentially severe clinical consequences if left untreated. Diagnostic and clinical management guidelines are strictly dependent on nature of laterality. This analysis aims to characterize the influence of laterality on survival in patients diagnosed with retinoblastoma.

Methods

This retrospective cohort analysis utilized the Surveillance, Epidemiology, and End Results (SEER) program for population-based clinical data from 1975 to 2016, a period of 41 years. Univariable and multivariable Cox regression assessed survival with laterality as the primary independent predictor of mortality. Adjustment for demographical and clinical variables was performed.

Results

N = 1925 patients with a valid cause of death classification. Mean±SD age was 2.35±2.020 years (range 0–74). At the time of diagnosis, 819 (42.1%) patients were between 0 and 1 year of age, 469 (24.1%) patients were between 1 and 2 years, 350 (18.0%) patients were between 2 and 3 years, 147 (7.6%) patients were between 3 and 4 years, and 68 (3.5%) patients were between 4 and 5 years of age. The hazard of univariable cause-specific death is 55.6% and 52.9% lower for retinoblastoma patients with left-sided origin and right-sided origin as compared to patients with bilateral origin, respectively (HR = 0.444, CI 0.247–0.800, p = 0.007; HR = 0.471, CI 0.267–0.832, p = 0.009). After adjusting for confounding variables, the hazard of other-cause death for retinoblastoma patients is significantly less for left-sided origin (HR = 0.364, CI 0.140–0.946, p = 0.038) and right-sided origin (HR = 0.190, CI 0.066–0.549, p = 0.002) as compared to patients with retinoblastomas of bilateral origin.

Conclusion

Prognostication of survival is significantly influenced by the nature of laterality in retinoblastoma. Unilateral retinoblastomas showcase increased promise for long-term cause-specific and other-cause survival compared to cases of retinoblastoma arising from bilateral origin.

Long-term risk of subsequent cancer incidence among hereditary and nonhereditary retinoblastoma survivors

BACKGROUND

Increased sarcoma and melanoma risks after hereditary retinoblastoma are well established, whereas less is known about epithelial subsequent malignant neoplasms (SMNs) and risks for multiple (≥2) SMNs.

METHODS

Leveraging long-term follow-up and detailed histologic information, we quantified incident SMN risk among 1128 hereditary and 924 nonhereditary retinoblastoma survivors (diagnosed 1914-2006; follow-up through 2016). Standardised incidence ratios (SIRs) compared cancer risk after retinoblastoma relative to the general population. We estimated cumulative incidence accounting for competing risk of death.

RESULTS

Hereditary survivors had statistically significantly increased SMN risk (N = 239; SIR = 11.9; 95% confidence interval [CI] 10.4-13.5), with SIRs >80-fold for sarcomas, nasal cavity tumours and pineoblastoma. Significantly increased risks were also observed for melanoma and central nervous system, oral cavity and breast SMNs (SIRs = 3.1-17), but not the uterus, kidney, lung, bladder, pancreas or other types. Cumulative incidence 50 years following hereditary retinoblastoma was 33.1% (95% CI 29.0-37.2) for a first SMN and 6.0% (95% CI 3.8-8.2) for a second SMN. SMN risk was not increased after nonhereditary retinoblastoma (N = 25; SIR = 0.8; 95% CI 0.5-1.2).

CONCLUSION

Beyond the established sarcoma and melanoma risks after hereditary retinoblastoma, we demonstrate increased risk for a more limited number of epithelial malignancies than previously suggested. Cumulative incidence estimates emphasise long-term SMN burden after hereditary retinoblastoma.

Outcomes of Intravenous Chemotherapy (Chemoreduction) for Retinoblastoma Based on Patient Age in 964 Eyes of 554 Patients

PURPOSE

To evaluate retinoblastoma control after intravenous chemotherapy (chemoreduction) by patient age at presentation.

DESIGN

Retrospective case series.

METHODS

This study included 964 eyes of 554 patients treated with chemoreduction at Ocular Oncology Service at Wills Eye Hospital. Patients received 6 monthly cycles of standard chemoreduction. Additional therapies for tumor control were performed as needed.

RESULTS

Of 964 eyes, a comparison by age group (<6 months vs. 6-12 months vs. 13-24 months vs. >24 months) revealed more advanced age group with higher frequency of group E tumor (15% vs. 25% vs. 32% vs. 39%, P < 0.001). By treatment outcomes, complete tumor control was achieved with chemoreduction alone more often in less advanced age group (46% vs. 30% vs. 17% vs. 8%, P < 0.001). Additional treatment after chemoreduction was needed more often in more advanced age group with external beam radiotherapy (EBRT; 9% vs. 16% vs. 20% vs. 15%, P = 0.006) or enucleation (12% vs. 18% vs. 26% vs. 37%, P < 0.001). Over time (1994-1998 vs. 1999-2003 vs. 2004-2008 vs. 2009-2013 vs. 2014-2019), the paradigm for additional required treatment after chemoreduction shifted toward less EBRT (27% vs. 24% vs. 14% vs. 7% vs. 2%, P < 0.001) and more intra-arterial (0% vs. 0% vs. 1% vs. 25% vs. 48%, P < 0.001) and intravitreal (0% vs. 0% vs. 3% vs. 10% vs. 20%, P < 0.001) chemotherapy.

CONCLUSIONS

Chemoreduction is a safe and effective treatment method for patients with retinoblastoma, demonstrating the best tumor control in the younger age groups.

Five-year experience in treatment of retinoblastoma with intra-arterial chemotherapy: A single-center analysis

Purpose:

To report our 5-year experience in treating retinoblastoma (RB) with intra-arterial chemotherapy (IAC) as a primary or secondary therapy, without adjuvant intravitreal chemotherapy.

Methods:

A retrospective study was conducted on 70 eyes with intraocular RB that were treated with primary or secondary IAC from December 2010-2015. Demographic characteristics, clinical features, tumor control, and treatment complications were compared and reported.

Results:

Thirty-seven eyes had received IAC as a secondary therapy after failed/incomplete response to systemic chemotherapy, and 33 eyes had received IAC as a primary treatment. The mean age of patients was 25 ± 8.9 months, and the patients were followed for a mean of 24.5 ± 16.26 months. Overall, enucleation rates were significantly higher in advanced tumors (Group D and E) in both groups (both P < 0.05). The main reason for enucleation in this study group was being unresponsive to treatment (27.4%), with 76% of latter patients having vitreous seeds at the time of enucleation. Enucleation rates did not differ significantly between patients receiving primary (18/33, 54%) or secondary IAC (18/37, 48%) (P = 0.06). In addition, recurrence and complication rates did not differ significantly between eyes receiving IAC as their primary or secondary treatment (P > 0.05).

Conclusion:

In primary and secondary treatment of RB with IAC, the main findings that are globe salvage, recurrence, and complication rates were comparable when no adjuvant intravitreal chemotherapy was used.

JQ1, a selective inhibitor of BRD4, suppresses retinoblastoma cell growth by inducing cell cycle arrest and apoptosis

Retinoblastoma (RB) is the most common intraocular cancer in children, and chemotherapy has been the first-line treatment. However, due to the side effects of chemotherapy drugs, novel treatments must be developed. JQ1, a selective inhibitor of BRD4, suppresses cell growth in several cancers in which BRD4 is overexpressed. In the present study, BRD4 was overexpressed in retinoblastoma, and JQ1 effectively inhibited RB cell proliferation and colony formation by inducing cell cycle arrest and promoting apoptosis. Furthermore, the Myc-P21-CDK2 and Myc-cyclinD3/CDK6 pathways were activated in RB cells treated with JQ1, and an animal experiment suggested that JQ1 significantly inhibited tumour growth in vivo. In conclusion, JQ1 may be a potential drug treatment for retinoblastoma.

EPZ015666, a selective protein arginine methyltransferase 5 (PRMT5) inhibitor with an antitumour effect in retinoblastoma

Retinoblastoma (RB) is the most common intraocular malignant tumour in infants, and chemotherapy has been the primary therapy method in recent years. PRMT5 is an important member of the protein arginine methyltransferase family, which plays an important role in various tumours. Our study showed that PRMT5 was overexpressed in retinoblastoma and played an important role in retinoblastoma cell growth. EPZ015666 is a novel PRMT5 inhibitor, and we found that it inhibited retinoblastoma cell proliferation and led to cell cycle arrest at the G1 phase. At the same time, EPZ015666 regulated cell cycle related protein (P53, P21, P27, CDK2) expression. In brief, our study showed that PRMT5 promoted retinoblastoma growth, the PRMT5 inhibitor EPZ015666 inhibited retinoblastoma in vitro by regulating P53-P21/P27-CDK2 signaling pathways and slowed retinoblastoma growth in a xenograft model.

Progressive Preretinal Fibrosis with Late, Ossifying, Proliferative Retinopathy following Treatment for Retinoblastoma

We report a case of retinal atrophy and progressive preretinal fibrosis in an eye previously treated with intravenous and intra-arterial chemotherapy (IAC), which evolved immediately after treatment with intravitreal injection of melphalan. The atrophy and fibrosis progressed later to proliferative retinopathy with dystrophic ossification. The patient was originally diagnosed with bilateral retinoblastoma at 4 months of age and was treated with systemic chemotherapy followed by IAC. New vitreous seeds developed and required treatment with intravitreal chemotherapy. There was resolution of vitreous seeding after 2 doses of intravitreal melphalan, but clinically the eye developed new, widespread retinal atrophy and fibrosis within 1 month of the second injection. This was followed by phthisis and late proliferative retinopathy nearly 1 year later. Retinoblastoma specialists should be aware of this potential complication of combined chemotherapy treatments.