Tylectomy Safety in Salvage of Eyes with Retinoblastoma

Retinoblastoma - A comprehensive review, update and recent advances

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

Retinoblastoma in Asia: Clinical Presentation and Treatment Outcomes in 2112 Patients from 33 Countries

PURPOSE

To describe the clinical presentation and treatment outcomes of children who received a diagnosis of retinoblastoma in 2017 throughout Asia.

DESIGN

Multinational, prospective study including treatment-naïve patients in Asia who received a diagnosis of retinoblastoma in 2017 and were followed up thereafter.

PARTICIPANTS

A total of 2112 patients (2797 eyes) from 96 retinoblastoma treatment centers in 33 Asian countries.

INTERVENTIONS

Chemotherapy, radiotherapy, enucleation, and orbital exenteration.

MAIN OUTCOME MEASURES

Enucleation and death.

RESULTS

Within the cohort, 1021 patients (48%) were from South Asia (SA), 503 patients (24%) were from East Asia (EA), 310 patients (15%) were from Southeast Asia (SEA), 218 patients (10%) were from West Asia (WA), and 60 patients (3%) were from Central Asia (CA). Mean age at presentation was 27 months (median, 23 months; range, < 1-261 months). The cohort included 1195 male patients (57%) and 917 female patients (43%). The most common presenting symptoms were leukocoria (72%) and strabismus (13%). Using the American Joint Committee on Cancer Staging Manual, Eighth Edition, classification, tumors were staged as cT1 (n = 441 [16%]), cT2 (n = 951 [34%]), cT3 (n = 1136 [41%]), cT4 (n = 267 [10%]), N1 (n = 48 [2%]), and M1 (n = 129 [6%]) at presentation. Retinoblastoma was treated with intravenous chemotherapy in 1450 eyes (52%) and 857 eyes (31%) underwent primary enucleation. Three-year Kaplan-Meier estimates for enucleation and death were 33% and 13% for CA, 18% and 4% for EA, 27% and 15% for SA, 32% and 22% for SEA, and 20% and 11% for WA (P < 0.0001 and P < 0.0001), respectively.

CONCLUSIONS

At the conclusion of this study, significant heterogeneity was found in treatment outcomes of retinoblastoma among the regions of Asia. East Asia displayed better outcomes with higher rates of globe and life salvage, whereas Southeast Asia showed poorer outcomes compared with the rest of Asia.

FINANCIAL DISCLOSURE(S)

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

Comparative study on genomic and epigenomic profiles of retinoblastoma or tuberous sclerosis complex via nanopore sequencing and a joint screening framework

Recurrence and extraocular metastasis in advanced intraocular retinoblastoma (RB) are still major obstacles for successful treatment of Chinese children. Tuberous sclerosis complex (TSC) is a very rare, multisystemic genetic disorder characterized by hamartomatous growth. In this study, we aimed to compare genomic and epigenomic profiles with human RB or TSC using recently developed nanopore sequencing, and to identify disease-associated variations or genes. Peripheral blood samples were collected from either RB or RB/TSC patients plus their normal siblings, followed by nanopore sequencing and identification of disease-specific structural variations (SVs) and differentially methylated regions (DMRs) by a systematic biology strategy named as multiomics-based joint screening framework. In total, 316 RB- and 1295 TSC-unique SVs were identified, as well as 1072 RB- and 1114 TSC-associated DMRs, respectively. We eventually identified 6 key genes for RB for further functional validation. Knockdown of CDK19 with specific siRNAs significantly inhibited Y79 cellular proliferation and increased sensitivity to carboplatin, whereas downregulation of AHNAK2 promoted the cell growth as well as drug resistance. Those two genes might serve as potential diagnostic markers or therapeutic targets of RB. The systematic biology strategy combined with functional validation might be an effective approach for rare pediatric malignances with limited samples and challenging collection process.

Management of retinoblastoma: are we there yet?

Since the introduction of intraarterial chemotherapy (IAC) in the last decade, there has been a paradigm shift in the management of retinoblastoma (RB), especially in developed countries. Despite improved globe salvage outcomes with IAC compared with systemic intravenous chemotherapy, IAC has certain limitations, such as poor accessibility and affordability, especially for middle- and low-income countries; the need for expertise; local ocular complications; and possible increased risk of systemic metastasis. This review discusses the important limitations of the current treatment strategy of using IAC, as well as the prospects of new therapeutic targets or routes of drug delivery that may lead to further improvements in the management of RB.

Adjuvant Chemotherapy Improves Survival for Children With Massive Choroidal Invasion of Retinoblastoma

Purpose

The purpose of this study was to investigate the effect of adjuvant chemotherapy on outcomes of children with massive choroidal invasion (MCI).

Methods

In this study, we reviewed the 5-year relapse-free survival (RFS) and overall survival (OS) of children diagnosed with MCI, managed with or without adjuvant chemotherapy. Excluded were children with additional other high-risk features (post-laminar optic nerve invasion, scleral invasion, or overt extraocular disease).

Results

Of 3566 children diagnosed with retinoblastoma, 2023 had enucleation, and 60 eyes of 60 children had pathology showing MCI without concomitant high-risk features. Enucleation was primary (22, 37%), or secondary (38, 63%) after failed eye salvage. Adjuvant systemic chemotherapy (median = 4, range = 1-8 cycles) was given to 48 of 60 (80%) children; 12 of 60 (20%) children had no adjuvant therapy. Five-year RFS was 88.5% (95% confidence interval [CI] = 79.7%-97.3%) and 5-year OS was 90.1% (95% CI = 81.7%-98.5%). Pre-enucleation chemotherapy did not affect RFS (89.7% vs. 75.0%; P = 0.657). Adjuvant chemotherapy improved RFS (97.2% vs. 55.6%; P < 0.001) and OS (97.2% vs. 66.7%; P < 0.001). In subgroup analysis, adjuvant chemotherapy improved RFS for both primarily enucleated (5-year RFS 100% vs. 50.0%; P = 0.002) and secondarily enucleated children (5-year RFS 95.8% vs. 60.0%; P = 0.005). The number of children treated with adjuvant chemotherapy to prevent one post-enucleation systemic relapse or death is three.

Conclusions

Adjuvant chemotherapy significantly decreased the risk of tumor relapse and death for children with pathological MCI. For every three children treated with adjuvant chemotherapy, one systemic relapse or death could be prevented.

Survival trends for patients with retinoblastoma between 2000 and 2018: What has changed?

INTRODUCTION

Retinoblastoma (RB) is the most common primary intraocular cancer of childhood. Over the last few decades, a variety of techniques and treatment modalities emerged that improved the survival and ocular salvage rate of patients with RB. We investigated the relative survival trends of patients with RB from 2000 to 2018 by using the Surveillance, Epidemiology, and End Results (SEER) database.

DESIGN

Retrospective database review.

METHODS

We extracted data from SEER 18 from 2000 to 2018. All patients with clinically diagnosed RB during the study period were included. We utilized SEER*Stat 8.3.9 and JPSurv software to estimate relative 5- and 10-year survival rates and trends and generated descriptive analyses with IBM SPSS.

MAIN OUTCOME MEASURES

Patient survival rates at 5- and 10-year after RB diagnosis.

RESULTS

RB was diagnosed in 1479 patients within the SEER 18 Program during our study period. The cohort comprised 776 (52.5%) males, 615 (41.6%) non-Hispanic whites, 487(32.9%) Hispanics, 1030 (69.6%) patients with unilateral disease, and 1087 (73.5%) patients with localized disease. Relative survival trends at 5- and 10-year significantly declined over the study periods (-0.42%, and -0.50% annually, respectively) but the decline was not significant in unilateral and bilateral RB cases separately.

CONCLUSIONS

Five- and ten-year relative survival trends declined from 2000 to 2018 and were significantly decreasing. Further studies that include more patients are needed to identify the factors contributing to reduced survival of patients with RB over time.

Pediatric Cataract Surgery Following Treatment for Retinoblastoma: A Case Series and Systematic Review

PURPOSE

To determine the visual and refractive outcomes and the ocular and systemic complications of cataract surgery in eyes treated for retinoblastoma.

DESIGN

Retrospective consecutive case series and systematic review.

METHODS

Children <18 years of age with retinoblastoma who underwent surgery for secondary cataract between 2000 and 2020 were reviewed. Medline (OVID), Embase, Web of Science, and the Cochrane database were searched from inception to August 2020.

RESULTS

A total of 15 eyes of 15 children were included. The mean age at retinoblastoma diagnosis was 12 months (median, 14; interquartile range [IQR], 4-19). Cataract developed at a mean age of 39 months (median, 31; IQR, 20-52), secondary to multiple treatments (n = 7), pars-plana vitrectomy (n = 3), external-beam radiotherapy (n = 2), laser (n = 2), and retinal detachment (n = 1). The mean preoperative quiescent interval was 44 months (median, 28; IQR, 15-64). Primary intraocular lens implantation was performed in 93%, posterior capsulotomy in 40%, and anterior vitrectomy in 33% of participants. Postoperatively, 100% had improved fundus visibility and 73% had improved vision. Complications included visual axis opacification (11 of 15), capsular phimosis (5 of 15), and zonulopathy (3 of 15). No patient developed intraocular recurrence, extraocular extension, or metastasis at a mean of 76 months (median, 78; IQR, 29-128) follow-up. The systematic review identified 852 studies, with 18 meeting inclusion criteria. Across all studies (n = 220 children), intraocular recurrence occurred in 6%, globe salvage in 91%, and extraocular extension and metastasis in <1%.

CONCLUSIONS

Modern retinoblastoma therapies, including intravitreal chemotherapy and vitrectomy, cause secondary cataract. Following cataract surgery, intraocular recurrence risk is low and extraocular spread is rare. Although surgery improves tumor visualization, visual prognosis may be limited by several factors. Challenges include biometry limitations and a high incidence of zonulopathy.