Results of a prospective study for the treatment of unilateral retinoblastoma

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.

Twenty-Year Retrospective Study of Post-Enucleation Chemotherapy in High-Risk Patients with Unilateral Retinoblastoma

Primary enucleation is a life-saving treatment for advanced intraocular retinoblastoma, particularly in patients with poor visual potential and functional contralateral eyes. This single-center study presents the treatment outcomes of patients with unilateral retinoblastoma who received primary enucleation and adjuvant chemotherapy with cyclophosphamide, vincristine, doxorubicin, and intrathecal methotrexate (CVDM) between 2000 and 2020. Twenty patients were enrolled in the study. The median age at diagnosis was 26 months (range, 1-45). Eighteen patients (90%) were in group E and two (10%) were in group D, according to the intraocular classification of retinoblastoma guidelines. Excluding one patient with an inadequate specimen, 19 patients (95%) had optic nerve involvement (ONI) at least up to the lamina cribrosa. Eight patients (40%) had choroidal invasion in addition to ONI. Two patients (10%) were surgical resection margin positive. The overall and event-free survival rates were 100% and 95%, respectively, for a median follow-up duration of 102.24 months (range 24.2-202.9). There were no relapses or deaths due to any cause, but one patient developed secondary rhabdomyosarcoma 99.6 months after chemotherapy. Treatment was well tolerated, with minimal hematotoxicity and hepatotoxicity. CVDM as a post-enucleation chemotherapy for advanced intraocular retinoblastoma has excellent outcomes with tolerable toxicity. However, in line with updated treatment trends, further risk stratification and lowering the treatment intensity should be considered. Continued long-term follow-up is required to further determine late effects.

Advanced Therapy and Clinical Trials to Treat Patients with Optic Nerve Diseases

Optic nerve diseases include a wide variety of pathogenic conditions triggering injury or dysfunction of the optic nerves that lead to visual impairment or blindness in one or both eyes. Despite their pathogenic variety, most of them proceed through common mechanisms that allow them to investigate together. Nevertheless, roles of the cells, tissues, genes, growth factors, and proteins, and all underlying pathophysiological mechanisms need to be studied fully for better management of each optic nerve disease. This review presents a collection of information regarding ongoing and completed clinical trials (CT) of advanced therapies that deliver stem cell and gene therapy treatments as drugs to patients with optic nerve diseases as well as successes and failures achieved in treating these patients in the last few years. These drugs seem safe from creating neurotoxicity. It describes outcomes of a bibliographic search for stem cell therapy, gene therapy, and neuroprotection-based CT registered in the International ClinicalTrials.gov, the European EudraCT, and the Spanish REEC database, and related papers published in the PUBMED database by applying different search terminologies. This review overall informs the patients of optic neurodiseases that advanced therapies are progressing successfully in search of effective and safe treatments for them.

Zebrafish as an Orthotopic Tumor Model for Retinoblastoma Mimicking Routes of Human Metastasis

BACKGROUND

Retinoblastoma (RB) is the most common eye cancer in children that has a high mortality rate when left untreated. Mouse models for retinoblastoma have been established but are time- and cost-intensive. The aim of this work was to evaluate an orthotopic transplantation model of retinoblastoma in zebrafish that also allows for tracking migratory routes and to explore advantages and disadvantages with respect to drug testing.

METHODS

Three fluorescence-labeled retinoblastoma cell lines (RB355, WERI-RB-1, Y79) were injected into the left eye of two-day-old zebrafish, while the un-injected right eye served as control. The migratory trajectories of injected retinoblastoma cells were observed until 8 days post injection (dpi), both in lateral and dorsal view, and measuring fluorescence intensity of injected cells was done for RB355 cells.

RESULTS

Time until the onset of migration and routes for all three retinoblastoma cell lines were comparable and resulted in migration into the brain and ventricles of the forebrain, midbrain and hindbrain. Involvement of the optic nerve was observed in 10% of injections with the RB355 cell line, 15% with Y79 cells and 5% with WERI-RB-1 cells. Fluorescence intensity of injected RB355 cells showed an initial increase until five dpi, but then decreased with high variability until the end of observation.

CONCLUSION

The zebrafish eye is well suited for the analysis of migratory routes in retinoblastoma and closely mirrors patterns of retinoblastoma metastases in humans.

The COVID-19 pandemic: A rapid global response for children with cancer from SIOP, COG, SIOP-E, SIOP-PODC, IPSO, PROS, CCI, and St Jude Global

The COVID-19 pandemic is one of the most serious global challenges to delivering affordable and equitable treatment to children with cancer we have witnessed in the last few decades. This Special Report aims to summarize general principles for continuing multidisciplinary care during the SARS-CoV-2 (COVID-19) pandemic. With contributions from the leadership of the International Society for Pediatric Oncology (SIOP), Children's Oncology Group (COG), St Jude Global program, and Childhood Cancer International, we have sought to provide a framework for healthcare teams caring for children with cancer during the pandemic. We anticipate the burden will fall particularly heavily on children, their families, and cancer services in low- and middle-income countries. Therefore, we have brought together the relevant clinical leads from SIOP Europe, COG, and SIOP-PODC (Pediatric Oncology in Developing Countries) to focus on the six most curable cancers that are part of the WHO Global Initiative in Childhood Cancer. We provide some practical advice for adapting diagnostic and treatment protocols for children with cancer during the pandemic, the measures taken to contain it (e.g., extreme social distancing), and how to prepare for the anticipated recovery period.

Treatment of Nonmetastatic Unilateral Retinoblastoma in Children

Importance

Multi-institutional collaborative studies that include large patient populations for the management of retinoblastoma with histopathological risk factors could provide important information for patient management.

Objective

To evaluate the implementation of a strategy for the management of nonmetastatic unilateral retinoblastoma in children based on standardized diagnostic and treatment criteria.

Design, Setting, and Participants

This single-arm prospective study applied a strategy based on a single-center experience. The setting was a multicenter study in Latin America (Grupo de America Latina de Oncologia Pediatrica [GALOP]). Participants were children with nonmetastatic unilateral retinoblastoma (staged with the International Retinoblastoma Staging System). The study opened on July 1, 2008, and closed on December 31, 2014. Follow-up was updated until June 30, 2017.

Interventions

Stage 0 patients (without enucleation) were given conservative therapy without a protocol. Stage I patients (with enucleation and no residual tumor) were divided into a high-risk group (retrolaminar invasion and/or scleral invasion) and a low-risk group (all remaining patients). High-risk children received adjuvant chemotherapy with 4 alternating cycles of regimen 1 (cyclophosphamide [65 mg/kg/d] [plus sodium-2-mercaptoethane sulfonate], idarubicin hydrochloride [10 mg/m2/d], and vincristine sulfate [0.05 mg/kg/d]) and 4 cycles of regimen 2 (carboplatin [500 mg/m2/d, days 1 and 2] and etoposide [100 mg/m2/d, days 1-3]). Low-risk children did not receive adjuvant therapy. Children with buphthalmia received neoadjuvant and adjuvant chemotherapy for a total of 8 cycles.

Main Outcomes and Measures

Probability of event-free survival (extraocular relapse and death from any cause were considered events).

Results

Among 187 children registered in the study, 175 were evaluable (92 [52.5%] female; median age, 22 months; age range, 3-100 months). Forty-two were stage 0 children, 84 were stage I low-risk children, and 42 were stage I high-risk children; there were 7 children in the buphthalmia group. With a median follow-up of 46 months, the 3-year probability of event-free survival was 0.97 (95% CI, 0.94-0.99), and the probability of overall survival was 0.98 (95% CI, 0.94-1.00). Stage 0 patients had no events, stage I low-risk patients had 1 event (orbital relapse treated with second-line therapy), stage I high-risk patients had 2 events (1 central nervous system relapse and 1 death from sepsis), and the buphthalmia group had 1 event (orbital relapse, followed by central nervous relapse and death).

Conclusions and Relevance

Adjuvant therapy may be effective for high-risk unilateral retinoblastoma but is toxic, and neoadjuvant chemotherapy for buphthalmus appears feasible.

Study of Unilateral Retinoblastoma With and Without Histopathologic High-Risk Features and the Role of Adjuvant Chemotherapy: A Children's Oncology Group Study

PURPOSE

To prospectively determine the prevalence of high-risk histopathologic features (HRFs) in patients with unilateral retinoblastoma who undergo enucleation and to evaluate the role of chemotherapy in preventing recurrences.

PATIENTS AND METHODS

Children newly diagnosed with enucleated unilateral retinoblastoma were enrolled prospectively. After central histopathology review, patients with specific HRFs received chemotherapy; others were observed. Primary end points were event-free survivals (EFS).

RESULTS

Of the 331 patients enrolled during 2005 to 2010, 321 eligible patients had central histopathologic review. Discordance between central review and contributing institutions occurred in 23% of patients with HRFs and in 17% of patients without HRFs. Postlaminar optic nerve involvement was present in 53 patients; 42 had massive posterior uveal invasion (≥ 3 mm); 15 had concomitant peripapillary 3 mm or greater choroid and postlaminar optic nerve involvement; and 15 had focal (< 3 mm) choroidal concomitant with lamina or prelamina optic nerve involvement. Two-year EFS for patients with HRFs requiring adjuvant chemotherapy was 0.96 (95% CI, 0.89 to 0.98), and 2-year EFS for patients without HRFs for which observation was indicated was 0.99 (95% CI, 0.96 to 1.0). The 2-year EFS for all patients was 0.98 (95% CI, 0.96 to 0.99).

CONCLUSION

Adequate handling and interpretation of histopathology of eyes with retinoblastoma is necessary to assign metastatic risk. Concomitant less than 3 mm choroidal and any prelaminar/laminar optic nerve invasion show no recurrence and may warrant no adjuvant chemotherapy. In contrast, concomitant greater than 3 mm peripapillary choroidal invasion and 1.5 mm or greater of postlaminar optic nerve invasion have the poorest outcomes, supporting the need for a more intensive adjuvant chemotherapy regimen for this subgroup. Strict criteria for adjuvant therapy may improve outcomes of children who undergo enucleation at diagnosis and may avoid unnecessary adjuvant chemotherapy for those who are not at risk for recurrence.

Clinical presentation and treatment outcome of retinoblastoma in children of South Western China

To study the clinical presentation and treatment outcome among children in South Western China with retinoblastoma (RB) and to determine factors predictive of poor outcome.A retrospective review of children diagnosed with RB from 2006 to 2015 at West China Hospital was undertaken. Demographic and clinical characteristics and treatment outcomes were studied.A total of 253 patients (unilateral 80.2%, bilateral 19.8%) were studied. Twenty six patients (10.3%) were from minority ethnic groups of China. The median onset age was 21 months. Leukocoria was the most common presenting sign (71%). Tumors were intraocular in 91.3% cases, extraocular in 8.7% cases. Extraocular RB patients had a longer median lag period than intraocular patients (9 months vs 2 months, P < 0.0001). In the intraocular group, 89.5% were advanced group D or E diseases. Enucleation was the major treatment for intraocular RB. However, over 10 years, the enucleation rate decreased constantly while more patients received chemotherapy. The Kaplan-Meier survival probability was 87.8%, 81.4%, and 74.8% at 3 years, 5 years, and 10 years, respectively. On Cox regression analysis, extraocular RB (P = 0.0008) and treatment abandonment (P < 0.0001) were associated with poor outcome; bilateral RB (P = 0.0116) and advanced pathological grade pT4 (P = 0.0011) were associated with poor outcome of intraocular RB.Most RB patients from South Western China were diagnosed at advanced clinical stage. Delayed presentation is related to extraocular RB which is a risk factor for poor outcome. Chemotherapy increased the eye salvage but had no effects to overall survival. Education for parents and general physicians for the early signs of RB (such as leukocoria), therapeutic strategy and treatment outcomes of RB may promote early diagnosis, improve the compliance, and outcome.

Retinoblastoma

Retinoblastoma is a rare cancer of the infant retina that is diagnosed in approximately 8,000 children each year worldwide. It forms when both retinoblastoma gene (RB1) alleles are mutated in a susceptible retinal cell, probably a cone photoreceptor precursor. Loss of the tumour-suppressive functions of the retinoblastoma protein (pRB) leads to uncontrolled cell division and recurrent genomic changes during tumour progression. Although pRB is expressed in almost all tissues, cone precursors have biochemical and molecular features that may sensitize them to RB1 loss and enable tumorigenesis. Patient survival is >95% in high-income countries but <30% globally. However, outcomes are improving owing to increased disease awareness for earlier diagnosis, application of new guidelines and sharing of expertise. Intra-arterial and intravitreal chemotherapy have emerged as promising methods to salvage eyes that with conventional treatment might have been lost. Ongoing international collaborations will replace the multiple different classifications of eye involvement with standardized definitions to consistently assess the eligibility, efficacy and safety of treatment options. Life-long follow-up is warranted, as survivors of heritable retinoblastoma are at risk for developing second cancers. Defining the molecular consequences of RB1 loss in diverse tissues may open new avenues for treatment and prevention of retinoblastoma, as well as second cancers, in patients with germline RB1 mutations.

Pathologic risk-based adjuvant chemotherapy for unilateral retinoblastoma following enucleation

BACKGROUND

There are no standardized diagnostic or treatment guidelines for patients with advanced unilateral retinoblastoma.

MATERIALS AND METHODS

Patients with advanced unilateral retinoblastoma were prospectively treated after enucleation using a risk-based protocol. Patients were assigned to low risk (LR), intermediate risk (IR), or high risk (HR) based on pathology. LR patients underwent observation. IR patients received 4 courses of chemotherapy with vincristine, doxorubicin, and cyclophosphamide (VDC). In the HR group, patients received 3 courses of VDC alternating with 3 courses of vincristine, carboplatin, and etoposide (VCE) and irradiation when indicated.

RESULTS

Fifty patients with advanced unilateral retinoblastoma were treated (LR, n=36; IR, n=7; HR, n=7). All eyes were Reese-Ellsworth group V. All bone scans (n=81), lumbar punctures (n=16), and bone marrow aspirates (n=16) were negative. Chemotherapy was well tolerated. Grades 3/4 hematologic toxicities were seen in all patients; grades 3/4 nonhematologic toxicities were seen in half the patients. Only one patient in the HR group received radiation therapy. All patients were alive at the time of analysis with no signs of disease recurrence. Median follow-up was 3.4 years (range, 0.8 to 6.4 y).

CONCLUSIONS

Patients with nonmetastatic unilateral retinoblastoma undergoing primary enucleation can be cured with a graduated intensity approach based on pathology.

Diagnostic delay and sociodemographic predictors of stage at diagnosis and mortality in unilateral and bilateral retinoblastoma

BACKGROUND

More invasive retinoblastoma, characterized by increased morbidity and mortality, with lower rates of eye salvage and higher rates of extraocular dissemination, seems more prevalent in resource-poor countries. The relationship of diagnostic delay (lag time) and sociodemographic factors on the extent of disease at diagnosis has not been examined separately for unilateral and bilateral retinoblastoma.

METHODS

At diagnosis, consenting parents of 179 Mexican children with retinoblastoma were interviewed about initial symptoms and household demographic characteristics. Clinical presentation was classified using St. Jude's, International Staging System (ISS), and International Intraocular Retinoblastoma Classification (IIRC) criteria. Lag time (delay between noting symptoms and diagnosis) and sociodemographic factors were examined as predictors for higher stage at diagnosis and overall survival (OS).

RESULTS

In bilateral disease, lag time predicts stage at diagnosis using St. Jude's, and ISS criteria (P < 0.005 in multivariate regression), and OS (P < 0.05, Cox hazards), but not extent of intraocular disease (by IIRC). In unilateral disease, lag time predicts neither extent of disease (using ISS, St Jude's, and IIRC), nor OS. Indicators of prenatal poverty, including lower maternal education and the presence of dirt flooring in the home, predict more advanced disease by IIRC for bilateral retinoblastoma, and for unilateral by ISS, and St Jude's (P < 0.001) as well as OS (P < 0.05).

CONCLUSION

These results suggest unilateral and bilateral retinoblastoma differs in factors governing progression and extraretinal extension, possibly reflecting underlying biologic heterogeneity.

IMPACT

This demonstrates differing effect of social factors on extent of intra- and extraocular disease depending on laterality with implications for screening strategies.

Retinoblastoma: Recent trends A mini review based on published literature

Retinoblastoma (RB) is the most common intraocular malignancy in children. Recently, there have been significant advances made in the molecular pathology and the management of the disease. Last decade has witnessed better understanding of the genetics of RB, the discovery of new tumor markers expressed by the RB tumors, the identification of high-risk histopathological factors following enucleation, and newer methods of treatment including periocular chemotherapy and superselective intraarterial chemotherapy. All these advances have translated in improved survival rates for the affected children, improved rates of eye salvage, and improved visual outcomes. This article briefly reviews these advances.Method of Literature Search: Literature on the Medline database was searched using the PubMed interface. The search strategy included MeSH and natural language terms using the keywords mentioned. Reference lists in retrieved articles and textbooks were also searched for relevant references.