Long-term outcomes of Group D retinoblastoma eyes during the intravitreal melphalan era

Intravitreal Melphalan versus Topotecan for Vitreous Seeds in Retinoblastoma: A Comparative Study of 64 Asian Indian Eyes

PURPOSE

To compare the outcomes of intravitreal melphalan (IVit-M) versus intravitreal topotecan (IVit-T) for vitreous seeds (VS) in retinoblastoma (RB).

DESIGN

Retrospective interventional study.

PARTICIPANTS

Patients of RB with VS receiving intravitreal chemotherapy (IVit-C) between December 2012 and December 2022, at a single quaternary ocular oncology referral center.

INTERVENTION

Intravitreal melphalan injection of 25 μg/0.1 mL in 25 eyes and IVit-T of 30 μg/0.15 mL in 39 eyes.

MAIN OUTCOME MEASURES

Resolution of VS, globe salvage, IVit-C-related complications.

RESULTS

The mean age at presentation was 28 months (median, 24 months; range, 4-144 months) for the IVit-M group and 25 months (median, 24 months; range, 2-60 months) for the IVit-T group. At the time of initiation of intravitreal injection, the VS belonged to type 1 (1 [4%] vs. 1 [3%]), type 2 (9 [36%] vs. 14 [36%]), type 3 (8 [32%] vs. 18 [46%]), or a combination of these (7 [28%] vs. 6 [15%]) in IVit-M and IVit-T groups, respectively. Complete resolution of VS after IVit-C was seen in 22 (92%) and 28 (72%) eyes (P = 0.069) in IVit-M and IVit-T groups, respectively. At a mean follow-up period of 44 months after the first IVit-C injection in the IVit-M group and 19 months in the IVit-T group, globe salvage was higher in the IVit-T group (77%) than in the IVit-M group (60%, P = 0.148), respectively. Posterior segment complications were significantly higher in the IVit-M group than in the IVit-T group (P < 0.001). These included retinal pigment epithelial atrophy (P < 0.001), optic atrophy (P < 0.001), vascular attenuation (P < 0.001), and retinal/subretinal hemorrhages (P = 0.004).

CONCLUSIONS

Intravitreal topotecan is as efficacious as IVit-M for controlling VS in RB, with a better safety profile in pigmented Asian Indian eyes.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Management of Intraocular Retinoblastoma: ICMR Consensus Guidelines

Retinoblastoma (RB) is the most common childhood intraocular malignancy. Delayed presentation due to a lack of awareness and advanced intraocular tumors are a common scenario in low-middle income countries (LMICs). Remarkable treatment advances have been made in the past few decades allowing globe salvage in advanced intraocular RB (IORB) including systemic chemotherapy with focal consolidation and targeted treatments like intraarterial chemotherapy and intravitreal chemotherapy. However, a lack of availability and affordability limits the use of such advances in LMICs. External beam radiotherapy, despite risk of second cancers in RB with germline mutations, still remains useful for recalcitrant RB not responding to any other treatment. When choosing conservative treatment for advanced IORB, the cost and long duration of treatment, morbidity from multiple evaluation under anesthesias (EUAs), side effects of treatment and risk of treatment failure need to be taken into account and discussed with the parents. In this article, the authors discuss the ICMR consensus guidelines on the management of IORB.

Aqueous Humor Liquid Biopsy as a Companion Diagnostic for Retinoblastoma: Implications for Diagnosis, Prognosis, and Therapeutic Options: Five Years of Progress

PURPOSE

To define the prospective use of the aqueous humor (AH) as a molecular diagnostic and prognostic liquid biopsy for retinoblastoma (RB).

METHODS

This is a prospective, observational study wherein an AH liquid biopsy is performed at diagnosis and longitudinally through therapy for patients with RB. Tumor-derived cell-free DNA is isolated and sequenced for single nucleotide variant analysis of the RB1 gene and detection of somatic copy number alterations (SCNAs). The SCNAs are used to determine tumor fraction (TFx). Specific SCNAs, including 6p gain and focal MycN gain, along with TFx, are prospectively correlated with intraocular tumor relapse, response to therapy, and globe salvage.

RESULTS

A total of 26 eyes of 21 patients were included with AH taken at diagnosis. Successful ocular salvage was achieved in 19 of 26 (73.1%) eyes. Mutational analysis of 26 AH samples identified 23 pathogenic RB1 variants and 2 focal RB1 deletions; variant allele fraction ranged from 30.5% to 100% (median 93.2%). At diagnosis, SCNAs were detectable in 17 of 26 (65.4%) AH samples. Eyes with 6p gain and/or focal MycN gain had significantly greater odds of poor therapeutic outcomes (odds ratio = 6.75, 95% CI = 1.06-42.84, P = .04). Higher AH TFx was observed in eyes with vitreal progression (TFx = 46.0% ± 40.4) than regression (22.0 ± 29.1; difference: -24.0; P = .049).

CONCLUSIONS

Establishing an AH liquid biopsy for RB is aimed at addressing (1) our inability to biopsy tumor tissue and (2) the lack of molecular biomarkers for intraocular prognosis. Current management decisions for RB are made based solely on clinical features without objective molecular testing. This prognostic study shows great promise for using AH as a companion diagnostic. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Aqueous VEGF-A Levels as a Liquid Biopsy Biomarker of Retinoblastoma Vitreous Seed Response to Therapy

Purpose

Regression of retinoblastoma vitreous seeds (VS) during intravitreal chemotherapy can be delayed, resulting in supernumerary injections. Similarly, VS relapse may not be clinically evident at first. A predictive biomarker of tumor regression and relapse could help guide real-time clinical decision making. Retinoblastoma is an oxygen-sensitive tumor; paradoxically, VS survive in the hypoxic vitreous. We hypothesized that VS elaborate pro-angiogenic cytokines. The purpose was to determine if pro-angiogenic cytokine signatures from aqueous humor could serve as a biomarker of VS response to treatment.

Methods

Multiplex ELISA was performed on aqueous from rabbit eyes with human retinoblastoma VS xenografts to identify expressed proangiogenic cytokines and changes in aqueous cytokine levels during intravitreal treatment were determined. Confirmatory RNAscope in situ hybridization for VEGF-A was performed on human retinoblastoma tumor sections and VS xenografts from rabbits. For human eyes undergoing intravitreal chemotherapy, serial aqueous VEGF-A levels measured via VEGF-A-specific ELISA were compared to clinical response.

Results

VEGF-A was highly expressed in human retinoblastoma VS in the xenograft model, and was the only proangiogenic cytokine that correlated with VS disease burden. In rabbits, aqueous VEGF-A levels decreased in response to therapy, consistent with quantitative VS reduction. In patients, aqueous VEGF-A levels associated with clinical changes in disease burden (regression, stability, or relapse), with changes in VEGF-A levels correlating with clinical response.

Conclusions

Aqueous VEGF-A levels correlate with extent of retinoblastoma VS, suggesting that aqueous VEGF-A may serve as a predictive molecular biomarker of treatment response.

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.

Primary Subretinal Seeding in Retinoblastoma: Clinical Presentation and Treatment Outcomes

Introduction

The aim of this study was to describe the clinical features and treatment outcomes of primary subretinal seeding (SRS) in patients with intraocular retinoblastoma (RB).

Methods

Descriptive analysis of primary SRS in 47 patients (50 eyes) with RB was performed.

Results

Mean age was 19 months (range, 2-72 months), and 55% (n = 26) of the subjects were male. At presentation, the SRS involved two or more quadrants in 88% of eyes. Most seeds appeared yellowish gray (66%) and round to oval in shape (48%). Two-thirds of SRS were seen posterior to the equator and within 5 mm from the main tumor. Associated features included subretinal fluid in 50 eyes (100%), total retinal detachment in 28 eyes (56%), and vitreous seeds in 20 eyes (40%). Treatment included intravenous chemotherapy (IVC) (n = 47; 94%), enucleation (n = 2; 4%), and intra-arterial chemotherapy (n = 1; 2%). SRS treatment included adjunct use of focal transpupillary thermotherapy and/or cryotherapy (n = 20; 40%). Retinal tumor control was achieved in 36 eyes (76%) with 32 eyes (78%) showing a type 3 regression pattern, while SRS completely regressed in 24 (48%) eyes, partially in 15 (30%) and worsened in 2 (4%) eyes. Over a mean follow-up of 30 months (range, 3-68 months), SRS recurrence was noted in 12 eyes (29%), globe salvage was achieved in 39 eyes (78%), and 1 (4%) patient died of presumed metastasis.

Conclusion

Primary SRS pose a therapeutic challenge during RB treatment. The SRS responds moderately to systemic IVC, with one-third cases showing SRS recurrence and one-fifth ultimately requiring enucleation.

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.

A single-blinded, randomized controlled trial of standard versus higher dose carboplatin-based intravenous chemotherapy for group D and E retinoblastoma

BACKGROUND

Access to intra-arterial chemotherapy for retinoblastoma in low- and middle-income countries (LMICs) is limited. There is a need to optimize the efficacy of systemic chemotherapy for advanced intraocular retinoblastoma, particularly in LMICs. The aim was to compare the efficacy of standard versus higher dose carboplatin-based intravenous chemotherapy for group D and E retinoblastoma.

METHODS

The single-center, single-blinded, randomized study was conducted during 2019-2021. Patients with newly diagnosed group D or E retinoblastoma were randomized to receive vincristine, etoposide, and standard versus higher dose (<36 months: 18.6 vs. 28 mg/kg; ≥36 months: 560 vs. 840 mg/m² ) carboplatin. Examination under anesthesia and ultrasonography was performed at diagnosis and following three cycles of chemotherapy. Group E eyes with poor likelihood of globe/vision salvage at diagnosis were excluded.

RESULTS

Thirty-two eyes of 30 patients were analyzed: 17 group D and 15 group E eyes. The tumor response to chemotherapy with regards to regression pattern (p = .72), tumor shrinkage (diameter: p = .11, height: p = .96), subretinal seeds (p = .91), and vitreous seeds (p = .9) were comparable between the two treatment arms. The globe salvage (group D [82% vs. 67%; p = .58]; group E [12.5% vs. 29%; p = .57]) and salvage of meaningful vision (group D [100% vs. 75%; p = .13]; group E [100% vs. 50%; p = .48]) were comparable between standard and higher dose arms. No excess treatment-related toxicity was observed in the higher dose arm.

CONCLUSIONS

Higher dose carboplatin-based intravenous chemotherapy did not result in superior globe or vision salvage in group D or E retinoblastoma.

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.

Retinoblastoma Survival Following Primary Enucleation by AJCC Staging

Primary enucleation of the eye with retinoblastoma is a widely accessible, life-saving treatment for retinoblastoma. This study evaluated the survival of patients following primary enucleation based on AJCC 8th edition staging. Included were 700 consecutive patients (700 eyes) treated with primary enucleation at 29 Chinese treatment centers between 2006 and 2015. Excluded were patients with less than one year follow-up, bilateral retinoblastoma, clinical evidence of extraocular disease at diagnosis, or prior focal or systemic therapy. The 5-year overall survival was 95.5%, and 5-year disease-specific survival (DSS) was 95.7%. Survival was better when enucleation was <26 days from diagnosis than delayed >26 days (96.1% vs. 86.9%; p = 0.017). Patients with eyes presenting with raised intraocular pressure with neovascularization and/or buphthalmos (cT3c) had worse 5-year DSS (87.1%) than those without (cT2b, 99.1%; cT3b, 98.7%; cT3d, 97.2%) (p < 0.05). The 5-year DSS based on pathological staging was pT1 (99.5%), pT2a (95.5%), pT3a (100%), pT3b (93.0%), pT3c/d (92.3%), and pT4 (40.9%). Patients with pT3 pathology who received six cycles of adjuvant chemotherapy had better 5-year DSS (97.7%) than those with no chemotherapy (88.1%; p = 0.06) and those who underwent 1–3 cycles (86.9%, p = 0.02) or 4–5 cycles (89.3%, p = 0.06). Patients with pT4 pathology who received six cycles of chemotherapy had better 5-year DSS than those with 0–5 cycles (63.6% vs. 16.7%; p = 0.02). Prompt primary enucleation yielded high long-term survival for children with retinoblastoma. The AJCC 8th edition staging is predictive of survival.

Intravitreal HDAC Inhibitor Belinostat Effectively Eradicates Vitreous Seeds Without Retinal Toxicity In Vivo in a Rabbit Retinoblastoma Model

Purpose

Current melphalan-based regimens for intravitreal chemotherapy for retinoblastoma vitreous seeds are effective but toxic to the retina. Thus, alternative agents are needed. Based on the known biology of histone deacetylases (HDACs) in the retinoblastoma pathway, we systematically studied whether the HDAC inhibitor belinostat is a viable, molecularly targeted alternative agent for intravitreal delivery that might provide comparable efficacy, without toxicity.

Methods

In vivo pharmacokinetic experiments in rabbits and in vitro cytotoxicity experiments were performed to determine the 90% inhibitory concentration (IC₉₀). Functional toxicity by electroretinography and structural toxicity by optical coherence tomography (OCT), OCT angiography, and histopathology were evaluated in rabbits following three injections of belinostat 350 µg (2× IC₉₀) or 700 µg (4× IC₉₀), compared with melphalan 12.5 µg (rabbit equivalent of the human dose). The relative efficacy of intravitreal belinostat versus melphalan to treat WERI-Rb1 human cell xenografts in rabbit eyes was directly quantified. RNA sequencing was used to assess belinostat-induced changes in RB cell gene expression.

Results

The maximum nontoxic dose of belinostat was 350 µg, which caused no reductions in electroretinography parameters, retinal microvascular loss on OCT angiography, or retinal degeneration. Melphalan caused severe retinal structural and functional toxicity. Belinostat 350 µg (equivalent to 700 µg in the larger human eye) was equally effective at eradicating vitreous seeds in the rabbit xenograft model compared with melphalan (95.5% reduction for belinostat, P < 0.001; 89.4% reduction for melphalan, P < 0.001; belinostat vs. melphalan, P = 0.10). Even 700 µg belinostat (equivalent to 1400 µg in humans) caused only minimal toxicity. Widespread changes in gene expression resulted.

Conclusions

Molecularly targeted inhibition of HDACs with intravitreal belinostat was equally effective as standard-of-care melphalan but without retinal toxicity. Belinostat may therefore be an attractive agent to pursue clinically for intravitreal treatment of retinoblastoma.

Inter-eye genomic heterogeneity in bilateral retinoblastoma via aqueous humor liquid biopsy

Germline alterations in the RB1 tumor suppressor gene predispose patients to develop retinoblastoma (RB) in both eyes. While similar treatment is given for each eye, there is often a variable therapeutic response between the eyes. Herein, we use the aqueous humor (AH) liquid biopsy to evaluate the cell-free tumor DNA (ctDNA) from each eye in a patient with bilateral RB. Despite the same predisposing germline RB1 mutation, AH analysis identified a different somatic RB1 mutation as well as separate and distinct chromosomal alterations in each eye. The longitudinal alterations in tumor fraction (TFx) corresponded to therapeutic responses in each eye. This case demonstrates that bilateral RB tumors develop separate genomic alterations, which may play a role in tumorigenesis and prognosis for eye salvage. Identifying these inter-eye differences without the need for enucleated tumor tissue may help direct active management of RB, with particular usefulness in bilateral cases.

Natural History of Untreated Retinoblastoma

Treatment abandonment is a leading cause of death in children with retinoblastoma worldwide. We studied children who abandoned treatment upfront at diagnosis to delineate the natural history of untreated retinoblastoma. Studied were children who received no treatment, diagnosed between 2007 and 2017 at 29 Chinese centers. Data were retrospectively collected from medical chart reviews and interviews with each patient's family. During the study period, 44 children received no treatment after diagnosis of retinoblastoma. Clinical or radiologic evidence of orbital extension was available for 25 children, and radiologic evidence of systemic metastasis was available for 12 children. Median times from diagnosis of intraocular tumor to orbital disease was 13.7 months, orbital disease to metastasis was 2.6 months, and metastasis to death was 2.0 months. Children with brain metastasis had shorter survival than those with metastasis to other sites (median 1.0 vs. 3.1 months; p = 0.015). Overall, 36% of patients died within 12 months of diagnosis, 77% within 24 months, 95% within 36 months and 100% within 48 months. While multiple factors influence refusal of treatment, insights into the natural history of retinoblastoma derived from real-world evidence can inform clinicians and parents that retinoblastoma is life-threatening and encourage urgent treatment at diagnosis.

Current Indications of Secondary Enucleation in Retinoblastoma Management: A Position Paper on Behalf of the European Retinoblastoma Group (EURbG)

Simple Summary

Although secondary enucleation (SE) is the treatment of choice for retinoblastoma eyes that did not respond favorably to conservative therapies, clear criteria for its indication are, however, currently missing. In this position paper on behalf of the European Retinoblastoma Group (EURbG), we discuss the available literature on SE, including its influence on metastases rate and survival, and propose guidelines to assist decision-making to interrupt eye-preserving therapies depending on the availabilities of advanced diagnostic and therapeutic modalities. Absolute indications to SE may be restricted to eyes with refractory tumor activity resisting all salvage treatments or eyes under apparent tumor control but no visual potential and irreducible complications. In contrast, eyes with an obscured optic nerve head and/or ocular complications amenable to specific surgical or medical management can be considered relative indications, provided that appropriate follow-up can be implemented and that parents are fully aware of a residual risk.

Abstract

Secondary enucleation (SE) puts an irreversible end to eye-preserving therapies, whenever their prolongation is expected to violate the presumed state of metastatic grace. At present, it must be acknowledged that clear criteria for SE are missing, leading to empiric and subjective indications commonly related to disease progression or relapse, disease persistence masking the optic nerve head or treatment-related complications obscuring the fundus view. This absence of evidence-based consensus regarding SE is explained by the continuously moving frontiers of the conservative management as a result of diagnostic and therapeutic advances, as well as by the lack of studies sufficiently powered to accurately stratify the risk of metastasis in conservatively treated patients. In this position paper of the European Retinoblastoma Group (EURbG), we give an overview of the progressive shift in the indications for SE over the past decades and propose guidelines to assist decision-making with respect to when SE becomes imperative or recommended, with corresponding absolute and relative SE indications. Further studies and validation of biologic markers correlated with the risk of metastasis are expected to set more precisely the frontiers of conservative management and thus consensual criteria for SE in the future.

Intravenous Chemotherapy for Retinoblastoma in the Era of Intravitreal Chemotherapy: A Systematic Review

Purpose

The published data on ocular survival following intravenous chemotherapy of retinoblastoma (RB) seems to be skewed by evolving practice patterns induced by use of intravitreal chemotherapy (iVitc). We aimed to explore potential role of iVitc for vitreous seeding for patients treated with intravenous chemotherapy (IVC).

Methods

A literature search was performed to identify cases of RB treated with primary IVC prior to advent of iVitc by various search engines (PubMed, Medline, and Google) from 1992 to 2018. Studies were excluded if number of cases were less than 40 or lacked data related to type of recurrence and its treatment. Rates and patterns of recurrence and its management were categorized.

Results

Out of 15 studies identified, only 10 studies (797 eyes) met the inclusion criteria. The mean age at presentation was 15.3 months (range 0-192.8 months). Unilateral cases represented 25% of the cohort. The ocular survival rate with primary IVC was 63% (500/797 eyes). Of the 297 eyes (37%) that failed IVC therapy, additional 99 eyes could be salvaged with EBRT (599/797 eyes, 75%). Remaining 198 eyes were enucleated (198/797 eyes 25%). K-M survival analysis could not be done due lack of sufficient data. Recurrences that occurred (mean 12.2 months) after completion of primary IVC included relapse of retinal tumor (143 eyes [48%]), vitreous seeding (73 eyes [25%]), subretinal seeding (49 eyes [16%]), or any combination (103 eyes [35%]). Out of 73 eyes with vitreous seeding, additional 66 eyes (90%) would have been salvaged with iVitc, potentially improving ocular survival rates to 71% (500 + 66/797).

Conclusions

Evolving practice patterns of RB treatment have unfavorably skewed published ocular survival rates following IVC. With incorporation of iVitc, the ocular survival rates with IVC can be potentially improved to be non-inferior to those achieved with intra-arterial chemotherapy.

Evaluation of intravitreal topotecan dose levels, toxicity and efficacy for retinoblastoma vitreous seeds: a preclinical and clinical study

Background

Current melphalan-based intravitreal regimens for retinoblastoma (RB) vitreous seeds cause retinal toxicity. We assessed the efficacy and toxicity of topotecan monotherapy compared with melphalan in our rabbit model and patient cohort.

Methods

Rabbit experiments: empiric pharmacokinetics were determined following topotecan injection. For topotecan (15 μg or 30 µg), melphalan (12.5 µg) or saline, toxicity was evaluated by serial electroretinography (ERG) and histopathology, and efficacy against vitreous seed xenografts was measured by tumour cell reduction and apoptosis induction. Patients: retrospective cohort study of 235 patients receiving 990 intravitreal injections of topotecan or melphalan.

Results

Intravitreal topotecan 30 µg (equals 60 µg in humans) achieved the IC₉₀ across the rabbit vitreous. Three weekly topotecan injections (either 15 µg or 30 µg) caused no retinal toxicity in rabbits, whereas melphalan 12.5 µg (equals 25 µg in humans) reduced ERG amplitudes 42%–79%. Intravitreal topotecan 15 µg was equally effective to melphalan to treat WERI-Rb1 cell xenografts in rabbits (96% reduction for topotecan vs saline (p=0.004), 88% reduction for melphalan vs saline (p=0.004), topotecan vs melphalan, p=0.15). In our clinical study, patients received 881 monotherapy injections (48 topotecan, 833 melphalan). Patients receiving 20 µg or 30 µg topotecan demonstrated no significant ERG reductions; melphalan caused ERG reductions of 7.6 μV for every injection of 25 µg (p=0.03) or 30 µg (p<0.001). Most patients treated with intravitreal topotecan also received intravitreal melphalan at some point during their treatment course. Among those eyes treated exclusively with topotecan monotherapy, all eyes were salvaged.

Conclusions

Taken together, these experiments suggest that intravitreal topotecan monotherapy for the treatment of RB vitreous seeds is non-toxic and effective.

Response criteria for intraocular retinoblastoma: RB-RECIST

Standardized guidelines for assessing tumor response to therapy are essential for designing and conducting clinical trials. The Response Evaluation Criteria In Solid Tumors (RECIST) provide radiological standards for assessment of solid tumors. However, no such guidelines exist for the evaluation of intraocular cancer, and ocular oncology clinical trials have largely relied on indirect measures of therapeutic response-such as progression-free survival-to evaluate the efficacy of treatment agents. Herein, we propose specific criteria for evaluating treatment response of retinoblastoma, the most common pediatric intraocular cancer, and emphasize a multimodal imaging approach for comprehensive assessment of retinoblastoma tumors in clinical trials.

Complete preclinical platform for intravitreal chemotherapy drug discovery for retinoblastoma: Assessment of pharmacokinetics, toxicity and efficacy using a rabbit model

Current melphalan-based intravitreal chemotherapy regimens for retinoblastoma vitreous seeds are effective, but cause significant ocular toxicity. We describe protocols for each step of a drug discovery pipeline for preclinical development of novel drugs to maximize efficacy and minimize toxicity. These protocols include: 1) determination of vitreous pharmacokinetics in vivo, 2) in vitro assessment of drug cytotoxicity against retinoblastoma based on empiric pharmacokinetics, 3) back-calculation of minimum injection dose to achieve therapeutic concentrations, 4) in vivo determination of maximum-tolerable intravitreal dose, using a multimodal, structural and functional toxicity-assessment platform, and 5) in vivo determination of drug efficacy using a rabbit orthotopic xenograft model of retinoblastoma vitreous seeds. We likewise describe our methodology for direct quantitation of vitreous seeds, and the statistical methodology for assessment of toxicity and efficacy in evaluating novel drugs, as well as for comparisons between drugs.•Multi-step pipeline for intravitreal chemotherapy drug discovery for retinoblastoma, using novel rabbit models.•Detailed protocols for determination of vitreous pharmacokinetics, calculation of optimal dose to inject to achieve therapeutic vitreous levels, determination of maximum tolerable dose using a novel complete toxicity-assessment platform, and in vivo efficacy against retinoblastoma using methodology to directly quantify vitreous tumor burden.•Associated statistical methodology is also presented.

Intravitreal melphalan hydrochloride vs propylene glycol-free melphalan for retinoblastoma vitreous seeds: Efficacy, toxicity and stability in rabbits models and patients

The use of intravitreal chemotherapy has revolutionized the treatment of advanced intraocular retinoblastoma, as intravitreal melphalan has enabled difficult-to-treat vitreous tumor seeds to be controlled, leading to many more eyes being saved. However, melphalan hydrochloride (MH) degrades rapidly in solution, increasing logistical complexity with respect to time between medication preparation and administration for intravitreal administration under anesthesia for retinoblastoma. A new propylene glycol-free melphalan (PGFM) formulation has greater stability and could therefore improve access and adoption of intravitreal chemotherapy, allowing more children to retain their eye(s). We compared the efficacy and toxicity of both formulations, using our rabbit xenograft model and clinical patient experience. Three weekly 12.5 μg intravitreal injections of MH or PGFM (right eye), and saline (left eye), were administered to immunosuppressed rabbits harboring human WERI-Rb1 vitreous seed xenografts. Residual live cells were quantified directly, and viability determined by TUNEL staining. Vitreous seeds were reduced 91% by PGFM (p = 0.009), and 88% by MH (p = 0.004; PGFM vs. MH: p = 0.68). All residual cells were TUNEL-positive (non-viable). In separate experiments to assess toxicity, three weekly 12.5 μg injections of MH, PGFM, or saline were administered to non-tumor-bearing rabbits. Serial electroretinography, optical coherence tomography (OCT) and OCT-angiography were performed. PGFM and MH both caused equivalent reductions in electroretinography amplitudes, and loss of retinal microvasculature on OCT-angiography. The pattern of retinal degeneration observed on histopathology suggested that segmental retinal toxicity associated with all melphalan formulations was due to a vitreous concentration gradient-effect. Efficacy and toxicity were assessed for PGFM given immediately (within 1 h of reconstitution) vs. 4 h after reconstitution. Immediate- and delayed-administration of PGFM showed equivalent efficacy and toxicity. In addition, we evaluated efficacy and toxicity in patients (205 eyes) with retinoblastoma vitreous seeds, who were treated with a total of 833 intravitreal injections of either MH or PGFM as standard of care. Of these, we analyzed 118 MH and 131 PGFM monotherapy injections in whom serial ERG measurements were available to model retinal toxicity. Both MH and PGFM caused reductions in electroretinography amplitudes, but with no statistical difference between formulations. Comparing those patient eyes treated exclusively with PGFM versus those treated exclusively with MH, efficacy for tumor control and globe salvage was equivalent (PGFM vs. MH: 96.2% vs. 93.8%, p = 0.56), but PGFM-treated eyes received fewer injections than MH-treated eyes (average 3.2 ± 1.9 vs. 6.4 ± 2.1 injections, p < 0.0001). Taken together, these rabbit experiments and our clinical experience in retinoblastoma patients demonstrate that MH and PGFM have equivalent efficacy and toxicity. PGFM was more stable, with no decreased efficacy or increased toxicity even 4 h after reconstitution. We therefore now use PGFM over traditional MH for our patients for intravitreal treatment of retinoblastoma.

Neonatal Retinoblastoma

Retinoblastoma is the most common ocular malignancy of childhood. With an estimated 300 cases annually in the United States, retinoblastoma is nevertheless considered a rare tumor. Although retinoblastoma primarily affects younger children, diagnosis during the neonatal age range is less common. However, an understanding of patients at risk is critical for appropriate screening. Early detection and treatment by a multidisciplinary specialty team maximizes the chance for survival and ocular/vision salvage while minimizing treatment-related toxicity. Testing for alterations in the RB1 gene has become standard practice, and informs screening and genetic counseling recommendations for patients and their families.

Intravitreal Melphalan for Retinoblastoma: The Impact of Toxicity on Recurrence and Ultimate Globe Salvage

Introduction

Intravitreal melphalan (IVM) has emerged as an efficacious treatment for vitreous seeding in retinoblastoma. Although rarely severe, IVM-related toxicity may be treatment limiting. There is paucity of data on the impact of IVM toxicity on new tumor formation and ultimate globe salvage.

Objectives

To investigate whether the grade of retinal toxicity post-IVM impacts retinal and seeding tumor recurrence, as well as the overall ability to salvage the eye.

Methods

A single-institution retrospective chart review was performed on 47 eyes of 42 patients who received systemic intravenous chemotherapy followed by IVM as salvage treatment for persistent or recurrent vitreous seeding. Chorioretinal toxicity was graded from 0 to 5.

Results

Toxicity grade was inversely associated with the risk of recurrence, where a one-unit increase in toxicity grade correlated with nearly a 54% reduction in the odds of tumor recurrence (OR 0.46 [0.25-0.84], p = 0.01). Similarly, toxicity grade was related to enucleation, where a one-unit increase in toxicity grade was associated with a 31% reduction in the odds of undergoing enucleation (OR 0.69 [0.40-1.18], p = 0.17).

Conclusions

While retinoblastoma therapy aims to limit toxicity, especially visually significant toxicity, eyes with higher grades of post-IVM toxicity are less likely to have retinal and seeding tumor recurrence.

TOXICITY AND EFFICACY OF INTRAVITREAL MELPHALAN FOR RETINOBLASTOMA: 25 µg Versus 30 µg

PURPOSE

To compare retinal toxicity as measured by electroretinogram, ocular, and patient survival in retinoblastoma treated with intravitreal melphalan at two concentrations (25 vs. 30 µg).

METHODS

Single-center, retrospective analysis of retinoblastoma eyes receiving 25-µg or 30-µg intravitreal melphalan from September 2012 to January 2019. Ocular toxicity was measured by electroretinogram of evaluable injections in 449 injections in 136 eyes. A repeated-measures linear mixed model with a random intercept and slope was applied to account for repeated measures for each eye.

RESULTS

Average decline in electroretinogram after each additional injection was -4.9 µV (95% confidence interval -6.3 to -3.4); electroretinogram declined by -4.6 µV (95% confidence interval -7.0 to -2.2) after 25-µg injections and -5.2 µV (95% confidence interval -6.6 to -3.8) after 30-µg injections (P = 0.66). Injection at a new clock site hour was associated with a -3.91-µV lower average (95% confidence interval -7.8 to -0.04).

CONCLUSION

Electroretinogram-measured toxicity in retinoblastoma eyes treated with intravitreal injections was not found to be different across 25-µg and 30-µg injections. There were no cases of extraocular extension or metastatic deaths in our patient population.

Cell-Free DNA Tumor Fraction in the Aqueous Humor Is Associated With Therapeutic Response in Retinoblastoma Patients

Purpose

The aqueous humor (AH) liquid biopsy enables in vivo evaluation of tumor-derived cell-free DNA (cfDNA) from retinoblastoma (RB) eyes. Herein, we test our hypothesis that longitudinal dynamics of AH cfDNA—including tumor fraction (TFx) and somatic copy number alteration (SCNA) amplitude—correspond to therapeutic response.

Methods

Eyes with ≥3 AH extractions during intravitreal chemotherapy (IVM) or at secondary enucleation between 2015 to 2019 were included. AH cfDNA was sequenced to assess RB SCNA amplitude; ichorCNA software was used to estimate TFx. Eyes without SCNAs or with TFx < 0.10 across all samples were excluded. Therapeutic responses for each eye were determined from clinical records. Statistical analyses included Mann-Whitney U and Pearson correlation tests.

Results

Twenty eyes of 20 patients underwent ≥3 AH extractions; 6 eyes lacked SCNAs or had TFx < 0.10 throughout sampling and were excluded. Clinical progression was associated with significantly higher SCNA amplitudes and TFx values than regression (P ≤ 0.04). Relative increases in TFx (ΔTFx 1.86 ± 2.22) were associated with disease progression, whereas relative decreases in TFx (ΔTFx 0.53 ± 0.36) were associated with disease regression (P < 0.00001). A ≥15% increase in TFx relative to baseline during treatment was associated with an over 90-fold increased likelihood of clinical progression (odds ratio = 90.67, 95% confidence interval = 8.30–990.16, P = 0.0002). TFx and SCNA amplitude were significantly positively correlated throughout sampling (P ≤ 0.002).

Conclusions

Longitudinal changes in AH-derived cfDNA TFx and SCNA amplitude are concordant with clinical responses of intraocular RB during active therapy.

Translational Relevance

Longitudinal evaluation of AH cfDNA may provide an objective, quantitative way to monitor therapeutic response and disease burden in RB patients.

Chemotherapy for Retinoblastoma: Impact of Intravitreal Chemotherapy

ABSTRACT

Chemotherapy is now the primary treatment of retinoblastoma in eyes with visual potential or those that are considered not advanced for retinoblastoma. In addition to intravenous chemotherapy (IVC), drugs delivered via alternative routes such as intra-arterial and intravitreal administration have emerged as promising options for management of retinoblastoma. Various studies have shown excellent results in salvaging nearly 100% of groups A-C eyes; however, intra-arterial chemotherapy (IAC) seems to offer superior local control rates as compared with IVC for advanced intraocular retinoblastoma (groups D and E eyes). Intravitreal chemotherapy (IVitC), that delivers the highest concentration of drug in the vitreous cavity while minimizing systemic drug concentration, has emerged in recent years (2012) as an effective treatment for refractory or persistent vitreous seeding. The role of concomitant and subsequent therapies is an important consideration, particularly the use of IVitC in combination with IAC. As IVitC became acceptable during the era of IAC, most of the patients treated previously with IVC did not receive IVitC. Therefore, it is possible that some of the IVC failures could have been avoided with the use of IVitC. We provide our perspective of published data that seems to be skewed by evolving practice patterns that project enhanced efficacy of IAC when compared with historic control rates achieved with IVC. In absence of better-quality data or randomized controlled trials, it is hard to establish superiority of one treatment over the other.

A single-arm study of systemic and sub-Tenon chemotherapy for Groups C and D intraocular retinoblastoma: A Children's Oncology Group study (ARET 0231)

BACKGROUND

Eyes with Group D intraocular retinoblastoma have low salvage rates. A pilot study showed safety and efficacy of sub-Tenon's fascia carboplatin with systemic chemotherapy supporting further study.

METHODS

Children with newly diagnosed bilateral intraocular retinoblastoma with at least one remaining Group C or D eye were treated with six courses of carboplatin/etoposide/vincristine (CEV) with sub-Tenon's fascia carboplatin for Group C/D eyes during courses 2-4. Local ophthalmic therapy started at course 3. The primary study objective was to determine the 1-year failure rate of Group D eyes.

RESULTS

The study closed prematurely due to poor accrual and 22 of 30 patients were evaluable for failure rate, contributing 25 Group D and four Group C eyes. Among the 25 Group D eyes, there were 13 failures within the first year of study enrollment including eight needing external beam radiotherapy (EBR) and five needing enucleation, resulting in 1-year failure rate of 52%. The failure rate was significantly lower than the historical rate of 70% (P = .039). The 1-year eye preservation rate for Group D eyes was 80% (20/25). One-year failure rate for Group C eyes was 25% (1/4); 1-year preservation rate was 100% without need for EBR. Systemic toxicity included Grade 3 hearing loss in two subjects, infections, neutropenia, and thrombocytopenia. Ocular toxicities included periorbital fat atrophy (13/29 = 45% eyes), optic nerve atrophy (1/29 = 3% eyes), and restrictive fibrosis (1/29 = 3% eyes).

CONCLUSIONS

Sub-Tenon's fascia carboplatin plus CEV was partially effective in Group D intraocular retinoblastoma but had unacceptable ocular toxicities.

Retinoblastoma: Etiology, Modeling, and Treatment

Retinoblastoma is a retinal cancer that is initiated in response to biallelic loss of RB1 in almost all cases, together with other genetic/epigenetic changes culminating in the development of cancer. RB1 deficiency makes the retinoblastoma cell-of-origin extremely susceptible to cancerous transformation, and the tumor cell-of-origin appears to depend on the developmental stage and species. These are important to establish reliable preclinical models to study the disease and develop therapies. Although retinoblastoma is the most curable pediatric cancer with a high survival rate, advanced tumors limit globe salvage and are often associated with high-risk histopathological features predictive of dissemination. The advent of chemotherapy has improved treatment outcomes, which is effective for globe preservation with new routes of targeted drug delivery. However, molecularly targeted therapeutics with more effectiveness and less toxicity are needed. Here, we review the current knowledge concerning retinoblastoma genesis with particular attention to the genomic and transcriptomic landscapes with correlations to clinicopathological characteristics, as well as the retinoblastoma cell-of-origin and current disease models. We further discuss current treatments, clinicopathological correlations, which assist in guiding treatment and may facilitate globe preservation, and finally we discuss targeted therapeutics for future treatments.

Chromosome 6p Amplification in Aqueous Humor Cell-Free DNA Is a Prognostic Biomarker for Retinoblastoma Ocular Survival

Aqueous humor contains tumor-derived cell-free DNA (cfDNA) and can serve as a liquid biopsy for retinoblastoma. We previously associated somatic copy-number alteration (SCNA) 6p gain with a 10-fold increased risk of enucleation. Here we provide a 2-year update to further explore 6p gain as a prognostic biomarker for ocular survival. Patients diagnosed with retinoblastoma from December 2014 to July 2019 from whom aqueous humor was sampled were included. cfDNA was extracted and shallow whole-genome sequencing performed to identify highly recurrent retinoblastoma SCNAs (gain of 1q, 2p, 6p, loss of 13q, 16q). 116 aqueous humor samples from 50 eyes of 46 patients were included: 27 eyes were salvaged, 23 were enucleated. Highly recurrent retinoblastoma SCNAs were found in 66% eyes. 6p gain was the most prevalent SCNA (50% eyes). It was particularly more prevalent in enucleated eyes (73.9%) than in salvaged eyes (29.6%; P = 0.004). 6p gain in aqueous humor cfDNA portended nearly 10-fold increased odds of enucleation (OR = 9.87; 95% confidence interval = 1.75-55.65; P = 0.009). In the enucleated eyes, 6p gain was associated with aggressive histopathologic features, including necrosis, higher degrees of anaplasia, and focal invasion of ocular structures. With extended follow-up and nearly double the aqueous humor samples, we continue to demonstrate 6p gain as a potential prognostic biomarker for retinoblastoma. IMPLICATIONS: Aqueous humor is a high-yield source of tumor-derived DNA in retinoblastoma eyes. Detection of 6p gain in the aqueous humor allows for targeted, patient-centered therapies based on this molecular prognostic marker. Prospective, multicenter studies with aqueous humor sampled from all eyes at diagnosis are warranted to validate these findings.

Outcomes of neonatal retinoblastoma in pre-chemotherapy and chemotherapy eras

Purpose

To quantify outcomes for neonatal retinoblastoma patients treated during the pre-chemotherapy (1980-1994) and chemotherapy (1995-2018) eras.

Methods

Retrospective review of retinoblastoma patients diagnosed within the first 28 days of life between 1/1/1980 and 11/30/2018. Student's t-test, Chi-square, and Fisher's exact test were performed to compare treatments and outcomes by era.

Results

There were 68 patients with neonatal retinoblastoma (12% unilateral and 88% bilateral). According to era (pre-chemotherapy vs. chemotherapy), the number of treated patients was 26 (38%) vs. 42 (62%). Primary treatment was external beam radiotherapy (50% vs. 1%,P < 0.001), plaque radiotherapy (17% vs. 0%,P < 0.001), focal treatment (transpupillary thermotherapy or cryotherapy) only (21% vs. 14%,P= 0.33), intravenous chemotherapy (0% vs. 81%,P < 0.001), enucleation (10% vs. 4%,P= 0.26), or exenteration (2% vs. 0%,P= 0.37). Outcomes included tumor control (79% vs. 94%,P= 0.02), globe salvage (75% vs. 91%,P= 0.02), final gross visual acuity for salvaged eyes 20/200 or better (66% vs. 89%,P < 0.01), and death (19% vs. 0%,P < 0.01).

Conclusion

Chemotherapy advancements for neonatal retinoblastoma have improved tumor control, globe salvage, visual acuity, and patient survival.

Retinoblastoma presentation, treatment and outcome in a large referral centre in Tehran: a 10-year retrospective analysis

BACKGROUND/OBJECTIVES

Early diagnosis, care and treatment of retinoblastoma is a challengeable issue for Iranian health system. This study was designed and conducted in a referral multidisciplinary centre in the capital city of Iran to evaluate management, care, prognosis and survival rates of paediatric patients with retinoblastoma.

METHODS

In this retrospective study, a total number of 309 patients younger than 15 years, diagnosed with retinoblastoma, who referred for diagnosis and treatment to MAHAK's Pediatric Cancer Treatment and Research Center (MPCTRC) from 2007 to 2017 were evaluated. All data were analyzed via SPSS version 22 software in regard of parametric and non-parametric data. Survival rates were analyzed using the Kaplan-Meyer method.

RESULTS

The mean age of patients was 20 months and the majority of patients (77%) had leukocoria as a common clinical symptom at the time of diagnosis. Primary treatment methods were systemic chemotherapy (94%), laser (35%) and primary enucleation (28%). Relapses occurred in nearly 42% of cases, and the median time from diagnosis to the first relapse was 9 months. At the time analyzing the data, 11% of patients died. Patients' 5-year OS and RFS rates were 79.6% and 41.5%, respectively.

CONCLUSION

Comparing results with other conducted studies identifies that the recurrence rate was high in our considered patients. Also, OS and RFS rates in our study were not as considerable as other reports. Screening methods, updating protocols and follow-up of patients may lead to improvements in survival rates of patients with retinoblastoma.

Impact of Systemic Chemotherapy and Delayed Enucleation on Survival of Children with Advanced Intraocular Retinoblastoma

PURPOSE

Primary enucleation is a well-established method to achieve cure for advanced intraocular retinoblastoma. Recent treatment advances have induced a trend toward trial eye salvage using chemotherapy or other modalities. We investigated how pre-enucleation/postenucleation systemic chemotherapy and the resulting delayed enucleation affect patient survival after failed trial eye salvage.

DESIGN

Multicenter, retrospective cohort study.

PARTICIPANTS

Children with Group D and E retinoblastoma primarily or secondarily enucleated at 29 Chinese treatment centers.

METHODS

Data reviewed included clinical staging, time from diagnosis to enucleation, numbers of cycles of carboplatin, etoposide/teniposide and vincristine chemotherapy, disease-specific survival (DSS), histopathology, and follow-up.

MAIN OUTCOME MEASURES

Primary outcome was DSS. Secondary outcome was histopathology of enucleated eyes.

RESULTS

Primarily enucleated eyes had significantly shorter delay from diagnosis to enucleation than eyes treated with pre-enucleation chemotherapy (P < 0.001). Delay between diagnosis and enucleation >3.5 months (Group D) and >2 months (Group E) decreased survival (Group D: P = 0.018; Group E: P = 0.017). Compared with primarily enucleated children, children with 1 to 3 cycles of pre-enucleation chemotherapy for Group E eyes had no significant difference in survival (P = 0.74), but those who received ≥4 cycles had worse survival (P = 0.025). After pre-enucleation chemotherapy, more children with Group E (but not Group D) eyes had high-risk histopathology (pT3/pT4) (Group D: P = 0.076; Group E: P < 0.001) and worse survival than those primarily enucleated (P < 0.001). Postenucleation chemotherapy improved survival of children with high-risk histopathology (pT3/pT4) (P = 0.001) but did not change survival of children with low-risk histopathology (pT1/pT2) (P = 0.52).

CONCLUSIONS

We observed that pre-enucleation chemotherapy offered no survival benefit and timely enucleation minimized risk of metastatic death. Postenucleation chemotherapy improved survival of children with high-risk histopathology but was not useful for those with low-risk histopathology. These findings facilitate informed discussion on the risks and benefits of delayed enucleation, the use of systemic chemotherapy for trial salvage of eyes with advanced intraocular retinoblastoma, and the specific children who benefit from postenucleation chemotherapy.

Establishment of a formal program for retinoblastoma: Feasibility of clinical coordination across borders and impact on outcome

Retinoblastoma is an ocular tumor that occurs in young children, in either heritable or sporadic manner. The relative rarity of retinoblastoma, and the need for expensive equipment, anesthesia, and pediatric ophthalmologic expertise, are barriers for effective treatment in developing countries. Also, with an average age-adjusted incidence of two to five cases per million children, patient number limits development of local expertise in countries with small populations. Lebanon is a small country with a population of approximately 4.5 million. In 2012, a comprehensive retinoblastoma program was formalized at the Children's Cancer Institute (CCI) at the American University of Beirut Medical Center, and resources were allocated for efficient interdisciplinary coordination to attract patients from neighboring countries such as Syria and Iraq, where such specialized therapy is also lacking. Through this program, care was coordinated across hospitals and borders such that patients would receive scheduled chemotherapy at their institution, and monthly retinal examinations and focal laser therapy at the CCI in Lebanon. Our results show the feasibility of successful collaboration across borders, with excellent patient and physician adherence to treatment plans. This was accompanied by an increase in patient referrals, which enables continued expertise development. However, the majority of patients presented with advanced intraocular disease, necessitating enucleation in 90% of eyes in unilateral cases, and more than 50% of eyes in bilateral cases. Future efforts need to focus on expanding the program that reaches to additional hospitals in both countries, and promoting early diagnosis, for further improvement of globe salvage rates.

Ocular toxicity of intravitreal melphalan for retinoblastoma in Chinese patients

Background

To evaluate the efficacy, complications, and clinical characteristics, including the ocular toxicity, of intravitreal melphalan(IVM) treatment for vitreous seeding in Chinese retinoblastoma patients.

Methods

This was a retrospective, non-comparative analysis including 30 consecutive eyes of 23 patients with viable persistent or recurrent vitreous seeding following retinoblastoma treatment. All of the eyes received IVM injections (20–33 μg). Vitreous seeding control, determination of the ocular toxicity, and the clinical characteristics of intravitreal melphalan treatments were observed.

Results

The mean patient age at the time of the injection was 28 months (median = 22 months, range = 12–50 months). In total, 80 injections were administered in 30 eyes, the overall enucleation-free survival rate was 83.3% (25/30). The complications included retinal pigment epithelium (RPE) and choroidal atrophy (19/30, 63.3%), pupillary synechiae (13/30, 43.3%), iris atrophy (12/30, 40%), retinal vascular occlusion (12/30, 40.0%), optic atrophy (6/30, 20%), vitreous hemorrhage (3/30, 10%), persistent hypotonia and phthisis bulbi (4/30 13.3%), and cataracts (8/30, 26.6%). Twelve eyes demonstrated grade 3 or greater IVM-associated retinal or anterior segment toxicity post injection. Mean dosage given showed significant difference between the groups. There were no significant differences in the retinal toxicity grades regarding the seed classification or seed regression patterns.

Conclusions

Intravitreal melphalan is an effective treatment for refractory vitreous seeding from retinoblastoma, but exhibits both anterior and posterior segment toxicity in Chinese patients.

Primary Intra-Arterial Chemotherapy for Retinoblastoma in the Intravitreal Chemotherapy Era: Five Years of Experience

Purpose

To report our 5-year experience with intra-arterial chemotherapy (IAC) in the intravitreal chemotherapy (IvitC) era.

Methods

Retrospective review of retinoblastoma treated with primary unilateral IAC in the IvitC era (2012-2017).

Results

There were 34 eyes treated with IAC alone versus 20 eyes treated with IAC plus IvitC for vitreous seeds. IAC (IAC alone vs. IAC plus IvitC) consisted of melphalan (41 vs. 10%) or melphalan plus topotecan (59 vs. 90%, p = 0.03). IvitC consisted of melphalan (60%) or melphalan plus topotecan (40%). Tumor control and globe salvage were achieved in 100% of group B and C eyes without IvitC. Despite more extensive vitreous seeds in the IvitC group (p < 0.01), comparison of IAC alone versus IAC plus IvitC revealed no difference in tumor control for group D (88 vs. 69%, p = 0.36) or group E (67 vs. 100%, p = 0.25) and no difference in globe salvage for group D (88 vs. 69%, p = 0.36) or group E (58 vs. 57%, p = 0.39).

Conclusions

IAC is effective as primary therapy for unilateral group B, C, D, and E retinoblastoma. IvitC is an important adjuvant therapy to achieve comparable globe salvage rates for group D and E eyes with persistent active vitreous seeds.

Genomic cfDNA Analysis of Aqueous Humor in Retinoblastoma Predicts Eye Salvage: The Surrogate Tumor Biopsy for Retinoblastoma

Tumor-derived cell-free DNA (cfDNA) has biomarker potential; therefore, this study aimed to identify cfDNA in the aqueous humor (AH) of retinoblastoma eyes and correlate somatic chromosomal copy-number alterations (SCNA) with clinical outcomes, specifically eye salvage. AH was extracted via paracentesis during intravitreal injection of chemotherapy or enucleation. Shallow whole-genome sequencing was performed using isolated cfDNA to assess for highly recurrent SCNAs in retinoblastoma including gain of 1q, 2p, 6p, loss of 13q, 16q, and focal MYCN amplification. Sixty-three clinical specimens of AH from 29 eyes of 26 patients were evaluated; 13 eyes were enucleated and 16 were salvaged (e.g., saved). The presence of detectable SCNAs was 92% in enucleated eyes versus 38% in salvaged eyes (P = 0.006). Gain of chromosome 6p was the most common SCNA found in 77% of enucleated eyes, compared with 25% of salvaged eyes (P = 0.0092), and associated with a 10-fold increased odds of enucleation (OR, 10; 95% CI, 1.8-55.6). The median amplitude of 6p gain was 1.47 in enucleated versus 1.07 in salvaged eyes (P = 0.001). The presence of AH SCNAs was correlated retrospectively with eye salvage. The probability of ocular salvage was higher in eyes without detectable SCNAs in the AH (P = 0.0028), specifically 6p gain. This is the first study to correlate clinical outcomes with SCNAs in the AH from retinoblastoma eyes, as such these findings indicate that 6p gain in the aqueous humor is a potential prognostic biomarker for poor clinical response to therapy.Implications: The correlation of clinical outcomes and SCNAs in the AH identified in the current study requires prospective studies to validate these finding before SCNAs, like 6p gain, can be used to predict clinical outcomes at diagnosis. Mol Cancer Res; 16(11); 1701-12. ©2018 AACR.

Integrated Treatment during the Intravitreal Melphalan Era: Concurrent Intravitreal Melphalan and Systemic Chemoreduction

Background

Intravitreal injection of melphalan (IVM) is safe and effective for the treatment of seeding in retinoblastoma. Current protocols require weekly injections during examination under anesthesia (EUA). To avoid additional anesthesia exposure for these children, IVM was initiated at the EUA concurrent with the 4th cycle of systemic chemoreduction in a series of 6 patients with persistent seeding.

Methods

A retrospective review was completed to assess treatment response compared to all patients at our center treated with IVM and systemic chemotherapy. Overall, 6 eyes of 6 patients were included; salvage therapy included systemic chemoreduction with vincristine, etoposide, and carboplatin and IVM for persistent seeding.

Results

IVM was initiated in all eyes at cycle 4 of their chemotherapy. Success in eradicating vitreous seeds was 100%; overall salvage rate was 67%. Anterior toxicity was observed in 2 out of 6 eyes and posterior toxicity in 4 out of 6 eyes.

Conclusion

The concurrent chemoreduction and IVM protocol demonstrated a similar efficacy of globe salvage while sparing children additional EUAs. However, the increased rates of observed melphalan-related toxicities for concurrent therapy are concerning. Further clinical experience is necessary to define the best initiation time and dosing schedule for IVM.

Comparison between intravenous chemotherapy and intra-arterial chemotherapy for retinoblastoma: a meta-analysis

Background

Intravenous chemotherapy (IVC) and intra-arterial chemotherapy (IAC) have become the primary treatments for retinoblastoma; however, some controversy remains over which method is more effective. We conducted a meta-analysis to compare the clinical efficacy of IVC and IAC.

Methods

We systematically searched literature published on PubMed, Embase, and Cochrane Library up to May 2017. Studies containing either IAC or IVC that reported on efficacy were included. The effects estimate was expressed as a pooled rate with 95% confidence interval (CI), using a fixed-effects or random-effects model.

Results

Twenty-six studies were identified which included 1541 eyes (IAC: 11 trials, 445 eyes; IVC: 16 trials, 1096 eyes). The mean follow-up times were 49.4 months (range, 13.0–105.3 months) for IVC and 21.7 months (range, 8.8–38.7 months) for IAC. For the International Classification of Intraocular Retinoblastoma (ICRB) grading, the overall success rate was higher with IAC than with IVC (75.7% [95%CI: 65.7%–83.6%] vs. 69.5% [95%CI: 51.9%–82.8%], P < 0.001). The globe salvage with IAC was higher than with IVC in group D eyes (79.5% [95%CI: 71.8%–85.4%] vs. 55.1% [95%CI: 45.6%–64.2%], P < 0.001), but not in groups B (95.8% [95%CI: 57.5%–99.7%] vs. 82.5% [95%CI: 58.9%–94.0%], P = 0.163), C (91.3% [95%CI: 65.9%–98.3%] vs. 89.0% [95%CI: 69.0%–96.7%], P = 0.212), and E eyes (51.2% [95%CI: 37.0%–65.2%] vs. 43.2% [95%CI: 18.3%–72.1%], P = 0.578). IAC and IVC were not significantly different regarding the recurrence and metastasis rates (15.0% vs. 15.4%, P = 0.148 and 2.7% vs. 0.6%, P = 0.194, respectively). For Reese-Ellsworth (RE) grading, IAC had a higher globe salvage in groups IV (90.9% [95%CI: 56.0%–98.7%] vs. 66.3% [95%CI: 32.4%–89.0%], P = 0.047) and V eyes (83.2% [95%CI: 72.0%–90.5%] vs. 59.9% [95%CI: 43.1%–74.6%], P = 0.003), but not in group I-III eyes (88.6% [95%CI: 58.3%–97.7%] vs. 88.1% [95%CI: 76.6%–94.4%], P = 0.244). The overall success rate was higher in IAC than in IVC (87.1% [95%CI: 78.1%–92.7%] vs. 77.3% [95%CI: 68.1%–84.4%], P = 0.033).

Conclusions

IAC may be superior to IVC for the treatment of retinoblastoma, with a higher overall success rate and higher globe salvage in group D or groups IV and V eyes.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4406-6) contains supplementary material, which is available to authorized users.

Metastatic retinoblastoma of the parotid and submandibular glands: a rare case report

Background

Retinoblastoma is the most common intraocular malignancy occurring in children. It can metastasize to the regional lymph nodes, central nervous system and distant organs usually the bones and bone marrow and very rarely to the soft tissue. Here, we report a case of unilateral retinoblastoma in a 4-year-old girl accompanied by a large metastasis of the parotid and submandibular glands that developed about 6 months previously and gradually increased in size 5 months after enucleation of the left eye.

Case presentation

A 4-year-old girl with a history of unilateral retinoblastoma presented with a large, painful and worsening mass (about 20 × 23 cm) of the left side of the neck. Following surgery, the orbital tumour was completely resected, and the large tumour invasion range in the left side of the neck was not resected completely. Histopathological examination revealed retinoblastoma of the orbit and the parotid and submandibular glands. After chemotherapy and additional local radiotherapy on the parotid and submandibular glands, the tumour was inactive and stable.

Conclusions

Delayed detection and inappropriate management contribute to poor outcomes. Fundus examinations, education regarding the early signs of RB, and optimization of the therapeutic strategy for RB may play important roles in ocular health.