Orbital retinoblastoma: An update

Evolving criteria for group E retinoblastoma: impact on outcomes

OBJECTIVE

To assess the impact of evolving criteria for group E retinoblastoma on ocular survival outcomes.

DESIGN

A retrospective observational study.

METHODS

Single-institution consecutive case series of patients with advanced intraocular retinoblastoma (groups D and E) were classified based on International Intraocular Retinoblastoma Classification (IIRC) and International Classification of Retinoblastoma (ICRB) criteria. The main outcomes measured were ocular survival, frequency of histopathologic risk factors (HRF), and the need for adjuvant therapy.

RESULTS

A total of 332 eyes of 298 patients were classified into group D (150, 45%) and E eyes (182, 55%) based on IIRC criteria. ICRB classification resulted in upstaging of 57 group D eyes (17%) to group E. Eyes that were upstaged to group E from D in the ICRB classification (E1) differed significantly, with a greater proportion undergoing primary enucleation (17 of 57, 30%) than those that were not (10 of 93, 11%) (p = 0.003). Similar significant differences were observed between group E2 and E3 eyes (p < 0.0001). Ocular survival according to Kaplan-Meier estimates at 12 months of 79%, 59%, 49%, and 1% differed significantly between all groups (ICRB D, E1, E2, and E3, respectively).

CONCLUSION

Proposed new subgrouping of group E eyes into E1, E2, and E3 based on clinical criteria is based upon natural history of tumor progression and is predictive of ocular survival. Preservation of the existing lower boundaries for group E by ICRB and IIRC offers the possibility of reanalyzing existing published data.

Recent progress in retinoblastoma: Pathogenesis, presentation, diagnosis and management

Retinoblastoma, the primary ocular malignancy in pediatric patients, poses a substantial threat to mortality without prompt and effective management. The prognosis for survival and preservation of visual acuity hinges upon the disease severity at the time of initial diagnosis. Notably, retinoblastoma has played a crucial role in unraveling the genetic foundations of oncogenesis. The process of tumorigenesis commonly begins with the occurrence of biallelic mutation in the RB1 tumor suppressor gene, which is then followed by a cascade of genetic and epigenetic alterations that correspond to the clinical stage and pathological features of the tumor. The RB1 gene, recognized as a tumor suppressor, encodes the retinoblastoma protein, which plays a vital role in governing cellular replication through interactions with E2F transcription factors and chromatin remodeling proteins. The diagnosis and treatment of retinoblastoma necessitate consideration of numerous factors, including disease staging, germline mutation status, family psychosocial factors, and the resources available within the institution. This review has systematically compiled and categorized the latest developments in the diagnosis and treatment of retinoblastoma which enhanced the quality of care for this pediatric malignancy.

The Potential of Aqueous Humor Sampling in Diagnosis, Prognosis, and Treatment of Retinoblastoma

Retinoblastoma (RB) is a rare malignant tumor that arises in the developing retina in one or both eyes of children. Pathogenic variants of the RB1 tumor suppressor gene drive the majority of germline and sporadic RB tumors. Considering the risk of tumor spread, the biopsy of RB tumor tissue is contraindicated. Advancement of chemotherapy has led to preservation of more eye globes. However, this has reduced access to tumor material from enucleation specimens. Recently, liquid biopsy of aqueous humor (AH) has advanced the RB tumor- or eye-specific genetic analysis. In particular, nucleic acid analysis of AH demonstrates the genomic copy number profiles and RB1 pathogenic variants akin to that of enucleated RB eye tissue. This advance reduces the previous limitation that genetic assessment of the primary tumor could be done only after enucleation of the eye. Additionally, nucleic acid evaluation of AH allows the exploration of the genomic landscape of RB tumors at diagnosis and during and after treatment. This review explores how AH sampling and AH nucleic acid analysis in RB patients assist in diagnosis, prognosis, and comprehending the pathophysiology of RB, which will ultimately benefit individualized treatment decisions to carefully manage this ocular cancer in children.

Clinical and Histopathologic Predictors of Survival Among Children With Retinoblastoma From Two Tertiary Health Facilities in Uganda

BACKGROUND

Retinoblastoma (RB) is a malignant tumour that develops from the immature cells of the retina. It is the most frequent type of paediatric intraocular cancer and is curable. Clinical and histological findings after enucleation of the affected eye dictate not only the patient's secondary care but also their prognosis. We assessed the clinical and histopathologic predictors of survival among children with RB from two tertiary health facilities in Uganda.

METHODS

This retrospective research utilized archived formalin fixed and paraffin-embedded blocks of eye specimens enucleated between 2014 and 2016 at Mbarara University of Science and Technology (MUST) Pathology Department and Ruharo Eye Centre (REC) in Mbarara, Uganda. The specimens were then processed and stained with haematoxylin and eosin. The confirmation of RB was made to include the histologic stage and features of the tumor. Biographic data of the patients and clinical features, such as leukocoria, proptosis, phthisis, staphyloma and buphthalmos, were retrieved from the records.

RESULTS

Males (55.1%, n=43) dominated the study population (N=78). The median age was 31 months. The most common clinical sign was leukocoria (69.2%, n=52), and the most predominant histopathological stage was stage 1 (41%, n=32). Optic nerve (ON) invasion was seen in 38.5% (n=30), choroidal invasion in 29.5% (n=23), scleral invasion in 7.7% (n=6) and orbital extension in 16.7% (n=13) of the cases. Flexner-Wintersteiner rosettes were seen in 34.6% (n=27). Necrosis was a prominent feature (71.8%, n=56). The two-year survival was estimated to be 61.5% (n=48). Leukocoria (risk ratio (RR) 1.1), female gender (RR 1.4), intralaminar ON invasion (RR 7.6) and a lack of orbital extension (RR 7) were significant predictors of survival.

CONCLUSION

Leukocoria and proptosis are noticeable clinical signs of RB. Most patients present while in stage one although stage four presentation is also common. Leukocoria, ON invasion, orbital extension and gender are significant factors predictive of survival in patients with RB.

Pharmacokinetics of Orbital Topotecan After Ophthalmic Artery Chemosurgery and Intravenous Infusion in the Swine Model

Purpose

Surgery, multiagent systemic chemotherapy, and radiation are used for patients with orbital retinoblastoma but are associated with unacceptable short- and long-term toxicity (including death). We studied orbital and systemic exposure of topotecan in the swine model after ophthalmic artery chemosurgery (OAC) and intravenous (IV) delivery.

Methods

Landrace pigs (n = 3) underwent 30-minute OAC of topotecan (4 mg), and samples were serially obtained from the femoral artery and from a microdialysis probe inserted into the lateral rectus muscle sheath of the infused eye as a surrogate of the orbital irrigation. Animals were recovered, and, after a wash-out period, plasma and microdialysate samples from the contralateral eye were collected after a 30-minute IV infusion of topotecan (4 mg). Samples were quantified by high-performance liquid chromatography, and population pharmacokinetic analysis was conducted using MonolixSuite.

Results

After OAC, median topotecan exposure in the orbit was 5624 ng × h/mL (range 3922-12531) compared to 23 ng × h/mL (range 18-75) after IV infusion. Thus, topotecan exposure in the orbit was 218-fold (range 75-540) higher after OAC than after IV infusion despite comparable systemic exposure (AUCpl) between routes (AUCpl, OAC: 141 ng × h/mL [127-191] versus AUCpl, IV: 139 ng × h/mL [126-186]). OAC was more selective to target the orbit because the median (range) orbital-to-plasma exposure ratio was 44 (28-65) after OAC compared to 0.18 (0.13-0.40) after IV infusion.

Conclusions

OAC of topotecan resulted in higher orbital exposure than after IV infusion and was a more selective route for local drug delivery. Patients with orbital retinoblastoma may benefit from a multimodal treatment strategy including OAC therapy.

Utility of bone marrow examination in retinoblastoma and their correlation with hematological features

Retinoblastoma makes up about 3% of all childhood malignancies. The frequency of metastatic retinoblastoma ranges from 4.8 to 11%. Assessing the bone marrow status of newly diagnosed patients is crucial because of the advantages of autologous bone marrow transplants for high-risk patients. This study aimed to determine the utility of bone marrow examination in cases of retinoblastoma and its correlation with hematological findings. This retrospective study was conducted at the Department of Pathology, King George's Medical University, Lucknow, India. A total of 34 cases of retinoblastoma with bone marrow examination were included in the study. Bone marrow infiltration was present in 17.65% (6/34) cases of retinoblastoma. Bone marrow aspirate myelogram showed that marrow metastasis in retinoblastoma was significantly linked with a reduced percentage of total myeloid cells (p=0.001) and segmented cells (p=0.006). The present study demonstrated that 15% (3/20) of retinoblastoma patients previously classified as nonmetastatic before bone marrow examination (stages I to III based on histology, imaging, and bone scan) had bone marrow metastases following bone marrow examination and were upgraded to stage IV. To conclude, a diligent and exhaustive search for metastatic cells in bone marrow is advised if the myelogram shows a reduced percentage of total myeloid and segmented cells. All stage II and stage III cases of retinoblastoma must undergo bone marrow examination for early metastasis detection, as it may result in an upgrade to stage IV disease, impacting the prognosis and necessitating distinct treatment modalities.

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.

Magnolol regulates miR-200c-3p to inhibit epithelial-mesenchymal transition and retinoblastoma progression by modulating the ZEB1/E-cadherin axis in vitro and in vivo

BACKGROUND

Retinoblastoma, the most common pediatric intraocular malignancy, can develop during embryogenesis, with most children being diagnosed at 3-4 years of age. Multimodal therapies are typically associated with high levels of cytotoxicity and side effects. Therefore, the development of novel treatments with minimal side effects is crucial. Magnolol has a significant anti-tumor effect on various cancers. However, its antitumor effect on retinoblastoma remains unclear.

PURPOSE

The study aimed to determine the effects of magnolol on the regulation of EMT, migration, invasion, and cancer progression in retinoblastoma and the modulation of miR-200c-3p expression and the Wnt/ zinc finger E-box binding homeobox 1 (ZEB1)/E-cadherin axis in vivo and in vitro.

METHODS

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay was used to evaluate magnolol-induced cell toxicity in the Y79 retinoblastoma cell line. Flow cytometry and immunostaining assays were performed to investigate the magnolol-regulated mitochondrial membrane potential and the intracellular and mitochondrial reactive oxygen species levels in Y79 retinoblastoma cells. Orthotopic and subcutaneous xenograft experiments were performed in eight-week-old male null mice to study retinoblastoma progression and metastasis. In situ hybridization and quantitative reverse transcription polymerase chain reaction (RT-qPCR) assays were performed to evaluate the level of the anti-cancer miRNA miR-200c-3p. The mRNA and protein levels of E-cadherin, β-catenin, α-smooth muscle actin (α-SMA), fibronectin-1, and ZEB1 were analyzed using RT-qPCR, immunoblot, immunocytochemistry, and immunohistochemistry assays in vitro and in vivo.

RESULTS

Magnolol increased E-cadherin levels and reduced the activation of the EMT signaling pathway, EMT, tumor growth, metastasis, and cancer progression in the Y79 retinoblastoma cell line as well as in the orthotopic and subcutaneous xenograft animal models. Furthermore, magnolol increased the expression of miR-200c-3p. Our results demonstrate that miRNA-200c-3p inhibits EMT progression through the Wnt16/β-catenin/ZEB1/E-cadherin axis, and the ZEB1 silencing response shows that miR-200c-3p regulates ZEB1-mediated EMT in retinoblastoma.

CONCLUSION

Magnolol has an antitumor effect by increasing E-cadherin and miRNA-200c-3p expression to regulate ZEB1-mediated EMT and cancer progression in retinoblastoma. The anti-tumor effect of magnolol by increasing E-cadherin and miRNA-200c-3p expression to regulate ZEB1-mediated EMT and cancer progression in retinoblastoma has been elucidated for the first time.

Title: Clinico-pathological and survival profiles of orbito-ocular tumors in Enugu Nigeria. Is there an emerging trend?

Background

Orbito-ocular tumors are rare, but they cause significant morbidity and mortality. There are reported variations in their pattern of presentation and frequency of occurrence.

Objective

To evaluate the occurrence, clinico-pathologic spectrum, and patterns of orbito-ocular neoplasms as well as the treatment and outcome profiles.

Methods

A 5-year retrospective analysis of consecutive patients treated for orbito-ocular tumors. We evaluated patterns of occurrence, clinic-pathological concordance, and outcome of treatment. Associations were evaluated with chi square and confidence interval. Data analysis was performed using SPSS for windows version 23 and inferences were judged using the 95% level of significance.

Results

Among 100 patients with orbito-ocular masses, 62 were histologically confirmed. The female to male ratio (F:M) was 1.0. Their ages ranged from 7 months to 93 years, mean = 33.4 ± 2.7 years. There was an age variation among tumor types. Patients with squamous cell carcinoma (SCC) had a mean age of 46.4 years, while for retinoblastoma the mean age was 3.09 years. All patients with retinoblastoma had proven macroscopic orbital extension. SCC was the most common tumor type (n = 19), however, among children, retinoblastoma (n = 11) was more common. Melanocytic nevus, sebaceous gland carcinoma, and adenocarcinoma of lacrimal gland (n = 6, n = 5, n = 5), respectively, among other tumors were treated. Concordance between clinical and histopathological diagnoses was obtained among 30 (48.3%) cases. 1-year and 3-year survival for retinoblastoma was 90% and 72.9%, respectively, and 78.9% and 68.4% for SCC.

Conclusion

SCC is currently the most common orbito-ocular tumor in our setting.

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.

Clinical, Genomic, and Pharmacological Study of MYCN-Amplified RB1 Wild-Type Metastatic Retinoblastoma

An uncommon subgroup of unilateral retinoblastomas with highly aggressive histological features, lacking aberrations in RB1 gene with high-level amplification of MYCN (MCYNamplRB1+/+) has only been described as intra-ocular cases treated with initial enucleation. Here, we present a comprehensive clinical, genomic, and pharmacological analysis of two cases of MCYNamplRB1+/+ with orbital and cervical lymph node involvement, but no central nervous system spread, rapidly progressing to fatal disease due to chemoresistance. Both patients showed in common MYCN high amplification and chromosome 16q and 17p loss. A somatic mutation in TP53, in homozygosis by LOH, and high chromosomal instability leading to aneuploidy was identified in the primary ocular tumor and sites of dissemination of one patient. High-throughput pharmacological screening was performed in a primary cell line derived from the lymph node dissemination of one case. This cell line showed resistance to broad spectrum chemotherapy consistent with the patient's poor response but sensitivity to the synergistic effects of panobinostat-bortezomib and carboplatin-panobinostat associations. From these cells we established a cell line derived xenograft model that closely recapitulated the tumor dissemination pattern of the patient and served to evaluate whether triple chemotherapy significantly prolonged survival of the animals. We report novel genomic alterations in two cases of metastatic MCYNamplRB1+/+ that may be associated with chemotherapy resistance and in vitro/in vivo models that serve as basis for tailoring therapy in these cases.

Unusual presentation of Retinoblastoma

Most cases of retinoblastoma are diagnosed before the age of 5 years. The cases in older age groups can have variable presentations leading to misdiagnosis and management challenges. We report a case of retinoblastoma in an 8-year-old female who was primarily referred as a case of sympathetic ophthalmia due to a co-incidental misleading history of penetrating eye injury to other eye 3 weeks prior. The patient complained of decreased vision in the left eye after 3 weeks of repair of the corneo-scleral laceration in the right eye. Visual acuity in the right and left eye was 3/60 and light perception respectively. The anterior segment examination showed moderate sized keratic precipitates, intense inflammatory cellular reaction with large fluffy cells, hypopyon and dense vitreous exudates. Ultrasonography showed abundant hyperechoic contents within the vitreous cavity in the left globe. The retino-choroid was thickened. The possibility of endophthalmitis and sympathetic ophthalmia was considered. Diagnostic vitrectomy was planned. Intraoperatively, after clearing the exudates, a yellowish white mass lesion was seen superiorly. Post- operatively contrast-enhanced MRI scan confirmed the presence of an enhancing mass lesion in the globe consistent with the diagnosis of intraocular retinoblastoma. Enucleation of left globe was done after chemotherapy. Thus, a high risk of suspicion has to be kept for this malignant tumour in children with unexplained visual loss.

Regional Anesthesia for Pediatric Ophthalmic Surgery: A Review of the Literature

Ophthalmic pediatric regional anesthesia has been widely described, but infrequently used. This review summarizes the available evidence supporting the use of conduction anesthesia in pediatric ophthalmic surgery. Key anatomic differences in axial length, intraocular pressure, and available orbital space between young children and adults impact conduct of ophthalmic regional anesthesia. The eye is near adult size at birth and completes its growth rapidly while the orbit does not. This results in significantly diminished extraocular orbital volumes for local anesthetic deposition. Needle-based blocks are categorized by relation of the needle to the extraocular muscle cone (ie, intraconal or extraconal) and in the cannula-based block, by description of the potential space deep to the Tenon capsule. In children, blocks are placed after induction of anesthesia by a pediatric anesthesiologist or ophthalmologist, via anatomic landmarks or under ultrasonography. Ocular conduction anesthesia confers several advantages for eye surgery including analgesia, akinesia, ablation of the oculocardiac reflex, and reduction of postoperative nausea and vomiting. Short (16 mm), blunt-tip needles are preferred because of altered globe-to-orbit ratios in children. Soft-tip cannulae of varying length have been demonstrated as safe in sub-Tenon blockade. Ultrasound technology facilitates direct, real-time visualization of needle position and local anesthetic spread and reduces inadvertent intraconal needle placement. The developing eye is vulnerable to thermal and mechanical insults, so ocular-rated transducers are mandated. The adjuvant hyaluronidase improves ocular akinesia, decreases local anesthetic dosage requirements, and improves initial block success; meanwhile, dexmedetomidine increases local anesthetic potency and prolongs duration of analgesia without an increase in adverse events. Intraconal blockade is a relative contraindication in neonates and infants, retinoblastoma surgery, and in the presence of posterior staphylomas and buphthalmos. Specific considerations include pertinent pediatric ophthalmologic topics, block placement in the syndromic child, and potential adverse effects associated with each technique. Recommendations based on our experience at a busy academic ophthalmologic tertiary referral center are provided.

PET/CT and PET/MRI in ophthalmic oncology (Review)

Orbital and ocular anatomy is quite complex, consisting of several tissues, which can give rise to both benign and malignant tumors, while several primary neoplasms can metastasize to the orbital and ocular space. Early detection, accurate staging and re-staging, efficient monitoring of treatment response, non-invasive differentiation between benign and malignant lesions, and accurate planning of external radiation treatment, are of utmost importance for the optimal and individualized management of ophthalmic oncology patients. Addressing these challenges requires the employment of several diagnostic imaging techniques, such as high-definition digital fundus photography, ultrasound imaging, optical coherence tomography, optical coherence tomography (OCT)-angiography, computed tomography (CT) and magnetic resonance imaging (MRI). In recent years, technological advances have enabled the development of hybrid positron emission tomography (PET)/CT and PET/MRI systems, setting new standards in cancer diagnosis and treatment. The capability of simultaneously targeting several cancer-related biochemical procedures using positron emitting-radiopharmaceuticals, while morphologically characterizing lesions by CT or MRI, together with the intrinsic quantitative capabilities of PET-imaging, provide incremental diagnostic information, enabling accurate, highly efficient and personalized treatment strategies. Aim of the current review is to discuss the current applications of hybrid PET/CT and PET/MRI imaging in the management of patients presenting with the most commonly encountered orbital and ocular tumors.

Minimally disseminated disease and outcome in overt orbital retinoblastoma

In this retrospective study of patients with overt orbital retinoblastoma, we evaluated minimally disseminated disease (MDD) in bone marrow and cerebrospinal fluid (CSF) using CRX and/or GD2 synthase as markers. Ten patients were evaluated-five (50%) at diagnosis and five upon relapse. MDD was detected in four cases (one in the bone marrow, two in the CSF, and in one case in both sites). All patients received chemotherapy and four received orbital radiotherapy. Seven patients relapsed or progressed and all of them died. Three patients remain in complete remission. There was no apparent correlation between MDD and the outcome.

Retinoblastoma in Asia

Asia-Pacific region bears a significant global burden of retinoblastoma (RB), therefore understanding RB in Asia-Pacific region is important. Based on the year 2013 population estimates, 43% (3452 of 8099 children) of the global burden of RB lives in 6 countries of Asia-Pacific region: 1486 children in India, 1103 children in China, 277 children in Indonesia, 260 children in Pakistan, 184 children in Bangladesh, 142 children in Philippines. There exists a wide disparity, technological and socio-economical, within countries in this region resulting in a varied pattern of clinical presentation and survival varies. Challenges in developing nations are not just technological, but also social. Opportunities emerge for research to study and understand the socio-economical aspects of the disease to develop interventions that are relevant culturally and feasible economically. Possible steps include disease education and counselling, universal screening, highly subsidized/free of cost treatment for low socioeconomic strata, raising funds through the government and non-governmental organizations, sensitization and training of man-power in screening, diagnosis and treatment, and developing new specialized centers with tele-ophthalmology services.