Management of advanced retinoblastoma

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.

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.

Update on chemotherapy modalities for retinoblastoma: Progress and challenges

Retinoblastoma stands as a paradigm of success in treating malignancies among pediatric patients. Over recent decades, the approach to managing retinoblastoma has evolved significantly, transitioning from the preservation of patients' lives to the preservation of eyes and vision while minimizing treatment-related complications. Chemotherapy, administered through diverse routes, has solidified its role as the cornerstone of retinoblastoma treatment. In addition to intravenous chemotherapy (IVC), alternative administration routes, including intraarterial (IAC), intravitreal, intracameral, and periocular delivery, have emerged as promising modalities for retinoblastoma management. Numerous studies have demonstrated outstanding outcomes, achieving nearly 100% salvage rates for eyes classified under groups A-C. However, for advanced intraocular retinoblastoma (groups D and E eyes), IAC appears to offer superior local control rates compared to IVC. Intravitreal injection of chemotherapeutic agents, when administered in a controlled and secure manner, holds promise in averting the need for enucleation and radiotherapy in advanced retinoblastoma cases presenting with vitreous seeds. The optimal chemotherapy strategy remains meticulously tailored based on numerous factors. This review provides a comprehensive update on chemotherapy across various routes, encompassing key considerations, dosages, administration methods, treatment outcomes, and potential complications. Furthermore, it explores emerging potential treatments and outlines future directions aimed at enhancing treatment outcomes.

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

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

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.

Piperlongumine inhibits proliferation and oncogenic MYCN expression in chemoresistant metastatic retinoblastoma cells directly and through extracellular vesicles

Ocular retinoblastoma malignancies, which develop into metastatic phenotypes, result in poor prognosis and survival for infant and child patients. To improve the prognosis of metastatic retinoblastoma, it is important to identify novel compounds with less toxic side effects and higher therapeutic efficacy compared to existing chemotherapeutics. Piperlongumine (PL), a neuroprotective, plant-derived compound has been explored for its anticancer activities both in vitro and in vivo. Here, we analyze the potential efficacy of PL for metastatic retinoblastoma cell treatment. Our data reveal that PL treatment significantly inhibits cell proliferation in metastatic retinoblastoma Y79 cells compared to the commonly used retinoblastoma chemotherapeutic drugs carboplatin, etoposide, and vincristine. PL treatment also significantly increases cell death compared to treatment with other chemotherapeutic drugs. PL-induced cell-death signaling was associated with significantly higher caspase 3/7 activities and greater loss of mitochondrial membrane potential. PL was also internalized into Y79 cells with an estimated concentration of 0.310pM and expression analysis revealed reduced MYCN oncogene levels. We next examined extracellular vesicles derived from PL-treated Y79 cells. Extracellular vesicles in other cancers are pro-oncogenic, mediating systemic toxicities via the encapsulation of chemotherapeutic drugs. Within metastatic Y79 EV samples, an estimated PL concentration of 0.026pM was detected. PL treatment significantly downregulated Y79 EV cargo of the oncogene MYCN transcript. Interestingly, non-PL-treated Y79 cells incubated with EVs from PL-treated cells exhibited significantly reduced cell growth. These findings indicate that in metastatic Y79 cells, PL exhibits potent anti-proliferation effects and oncogene downregulation. Importantly, PL is also incorporated into extracellular vesicles released from treated metastatic cells with measurable anti-cancer effects on target cells at a distance from the site of primary treatment. The use of PL in the treatment of metastatic retinoblastoma may reduce primary tumor proliferation and inhibit metastatic cancer activity systemically via extracellular vesicle circulation.

TGF-β Superfamily Signaling in the Eye: Implications for Ocular Pathologies

The TGF-β signaling pathway plays a crucial role in several key aspects of development and tissue homeostasis. TGF-β ligands and their mediators have been shown to be important regulators of ocular physiology and their dysregulation has been described in several eye pathologies. TGF-β signaling participates in regulating several key developmental processes in the eye, including angiogenesis and neurogenesis. Inadequate TGF-β signaling has been associated with defective angiogenesis, vascular barrier function, unfavorable inflammatory responses, and tissue fibrosis. In addition, experimental models of corneal neovascularization, diabetic retinopathy, proliferative vitreoretinopathy, glaucoma, or corneal injury suggest that aberrant TGF-β signaling may contribute to the pathological features of these conditions, showing the potential of modulating TGF-β signaling to treat eye diseases. This review highlights the key roles of TGF-β family members in ocular physiology and in eye diseases, and reviews approaches targeting the TGF-β signaling as potential treatment options.

High-Risk Histopathologic Features of Retinoblastoma Treated at a Tertiary Hospital in West Java, Indonesia

Purpose

To evaluate the histopathological characteristics of clinically advanced retinoblastoma (RB) and its relationship with tumor differentiation.

Methods

This was a cross-sectional study of primary enucleated group D/E intraocular RB using medical records from 2017 to 2020 in a tertiary referral hospital. Cases with incomplete histopathological results were excluded. Tumors were classified into well, moderately, and poorly differentiated and undifferentiated. High-risk histopathological features were classified as per Thaung and Karaa [Community Eye Health. 2018;31(101):17-3].

Results

This study included 121 patients (129 eyes), of which 32.2% were diagnosed at 25-36 months. High-risk features (HRFs) were found in 100/129 eyes, and of 73 complete histopathological results, the 2 most common HRFs were postlaminar optic nerve invasion and massive choroidal invasion. RB was poorly differentiated in 69.9% and well differentiated in 12.3% of eyes. There was no statistically significant association between any HRFs and tumor differentiation, with age >2 years associated with tumor differentiation (p < 0.05).

Conclusion

The frequency of HRFs is 77.5% of primary enucleated eyes, mainly poorly and undifferentiated cells, particularly in children aged >2 years old.

Management and Outcomes of Unilateral Group D Tumors in Retinoblastoma

Purpose

Retinoblastoma presents most commonly as advanced unilateral disease, particularly in developing countries for which primary enucleation has been the preferred method of treatment. However, with the evolution of newer treatment modalities including intravitreal chemotherapy, intra-arterial chemotherapy and newer chemotherapeutic combinations, a trend towards more conservative approaches is being observed. Our aim is to evaluate outcomes of group D eyes following conservative and non-conservative treatment options.

Patients and Methods

The ocular oncology database was used to identify eyes with unilateral retinoblastoma that fulfilled the International Intraocular Retinoblastoma Classification (IIRC) group D criteria from August 2010 to August 2018 and these were retrospectively reviewed. Overall, 39 eyes were identified.

Results

Nineteen (49%) eyes underwent primary enucleation and 20 (51%) received eye-conserving treatment. Eye salvage was possible in 15 (75%) eyes in the attempted salvage group. None of the patient revealed signs of metastasis. All eyes received conventional chemotherapy (carboplatin, vincristine, etoposide) and focal laser therapy. Additional treatment modalities offered included intravitreal chemotherapy, intra-arterial chemotherapy and topotecan. Three (11%) eyes in the primary enucleation group showed high-risk features on histopathology and none developed metastasis.

Conclusion

The results of the study seem promising and conservative measures can be adopted in selected unilateral group D eyes.

Clinical Presentations and Outcomes of Retinoblastoma Patients in relation to the Advent of New Multimodal Treatments: A 12-Year Report from Single Tertiary Referral Institute in Thailand

PURPOSE

To investigate the clinical presentations and outcomes of retinoblastoma in relation to the advent of new multimodal treatments in Thailand. Patients and Methods. Retrospective case series. We evaluated the clinical presentation, staging, details of treatment, and treatment outcomes of retinoblastoma patients who were treated at Ramathibodi Hospital, Bangkok, Thailand, between January 1, 2007, and December 31, 2018. The log-rank test was used to explore clinical characteristics and treatment modalities that affected globe salvage and survival curves.

RESULTS

This study included 124 eyes of 81 patients with retinoblastoma. Forty-three patients (53.1%) had bilateral retinoblastoma. The median age at diagnosis was 8 months (range, 1-48 months). Of 124 eyes, 9 eyes (7.3%) had extraocular retinoblastoma and 115 eyes (92.7%) had intraocular retinoblastoma, which were classified by the International Classification of Retinoblastoma (ICRB) as group A, 4 eyes (3.5%); group B, 19 eyes (16.5%); group C, 6 eyes (5.2%); group D, 31 eyes (27%); and group E, 56 eyes (47.8%). Treatment included systemic chemotherapy, intra-arterial chemotherapy, ruthenium-106 plaque brachytherapy, external beam radiation therapy, cryotherapy, transpupillary thermotherapy, subtenon chemotherapy, and intravitreal chemotherapy. At the median follow-up period of 38.4 months (range, 0.2-148.2 months), the overall globe salvage rate of intraocular retinoblastoma was 51.7%. For unilateral retinoblastoma, globe salvage rate was 37.5% (group B, 100%; group C, 100%; group D, 50%; and group E, 18.8%). For bilateral intraocular retinoblastoma, the globe salvage rate was 57.8% (group A, 100 %; group B, 94.4%; group C, 100%; group D, 64.7%; and group E, 28.2%). The overall survival rate was 93.8%.

CONCLUSIONS

Recent advanced treatment modalities have improved the probability of globe salvage. However, enucleation remains an important life-saving intervention in many advanced cases.

Delayed metastasis in patients with intraocular retinoblastoma: A review of three cases

PURPOSE

To discuss the clinical presentation, management, and outcome of delayed metastasis in retinoblastoma (RB).

METHODS

Retrospective case series of three patients.

RESULTS

Mean age at diagnosis of RB was 29 months (median, 28 months; range, 11-48 months). All were males with non-familial bilateral intraocular RB. Primary treatment for RB included intravenous chemotherapy in all three cases. Secondary treatment included transpupillary thermotherapy/cryotherapy (n = 6 eyes), periocular chemotherapy (n = 2 eyes), intravitreal chemotherapy (n = 1 eye), intra-arterial chemotherapy (n = 1 eye), external beam radiotherapy (EBRT; n = 2 eyes), and enucleation (n = 2 eyes). Primary tumor regression was achieved in all cases and remained status quo at the time of diagnosis of distant metastasis. Two patients developed bone metastasis (ulna; tibia) and one developed soft tissue metastasis (temporal fossa) over a mean follow-up period of 6 years (median, 7 years; range, 5-8 years) from diagnosis of RB. Mean age of detection of metastatic disease was 8 years (median, 8 years; range, 7-9 years). All the lesions were solitary and the diagnosis of metastatic retinoblastoma was confirmed by tissue biopsy. Metastatic disease was treated with surgical excision (n = 1), chemotherapy (n = 2), and EBRT (n = 2). All patients are alive, with two patients free of disease over a mean follow-up period of 23 months (median, 23 months; range, 12-33 months); and 1 in remission 7 months after completion of EBRT.

CONCLUSION

Long-term follow-up of RB cases is mandatory. In spite of intraocular tumor regression, metastasis can still occur many years after treatment of RB.

ACVR1C/SMAD2 signaling promotes invasion and growth in retinoblastoma

Retinoblastoma is the most common intraocular cancer in children. While the primary tumor can often be treated by local or systemic chemotherapy, metastatic dissemination is generally resistant to therapy and remains a leading cause of pediatric cancer death in much of the world. In order to identify new therapeutic targets in aggressive tumors, we sequenced RNA transcripts in five snap frozen retinoblastomas which invaded the optic nerve and five which did not. A three-fold increase was noted in mRNA levels of ACVR1C/ALK7, a type I receptor of the TGF-β family, in invasive retinoblastomas, while downregulation of DACT2 and LEFTY2, negative modulators of the ACVR1C signaling, was observed in most invasive tumors. A two- to three-fold increase in ACVR1C mRNA was also found in invasive WERI Rb1 and Y79 cells as compared to non-invasive cells in vitro. Transcripts of ACVR1C receptor and its ligands (Nodal, Activin A/B, and GDF3) were expressed in six retinoblastoma lines, and evidence of downstream SMAD2 signaling was present in all these lines. Pharmacological inhibition of ACVR1C signaling using SB505124, or genetic downregulation of the receptor using shRNA potently suppressed invasion, growth, survival, and reduced the protein levels of the mesenchymal markers ZEB1 and Snail. The inhibitory effects on invasion, growth, and proliferation were recapitulated by knocking down SMAD2, but not SMAD3. Finally, in an orthotopic zebrafish model of retinoblastoma, a 55% decrease in tumor spread was noted (p=0.0026) when larvae were treated with 3 μM of SB505124, as compared to DMSO. Similarly, knockdown of ACVR1C in injected tumor cells using shRNA also resulted in a 54% reduction in tumor dissemination in the zebrafish eye as compared to scrambled shRNA control (p=0.0005). Our data support a role for the ACVR1C/SMAD2 pathway in promoting invasion and growth of retinoblastoma.

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.

Orbital retinoblastoma: An update

Orbital extension is a major cause of death in children with retinoblastoma in the developing countries. Delayed detection and inappropriate management contribute to poor outcome. Conventional treatment including primary orbital exenteration or chemotherapy or radiotherapy alone result in mortality as high as 70%. The recent understanding on the role of sequential multimodal therapy with a combination of high-dose chemotherapy, followed by appropriate surgery, radiotherapy, and additional adjuvant chemotherapy has helped dramatically improve life salvage.

Recent advances and challenges in the management of retinoblastoma

The treatment of retinoblastoma (Rb) has improved significantly in recent times. Worldwide, there is an increasing trend to use conservative treatment modalities that aim to preserve the globe as well as vision with minimum morbidity. Recently, the use of targeted delivery of chemotherapy to the eye in the form of selective intra-arterial and intravitreal chemotherapy has shown promising results. Radiotherapy is beneficial in selected cases, either in the form of plaque brachytherapy or as external beam radiotherapy. Orbital disease carries a poor prognosis for survival. However, a multimodal treatment protocol has improved survival in children with extraocular disease. Nevertheless, challenges remain, especially for the developing world. This review aims to highlight recent advances in the management of Rb that have contributed towards improving treatment outcomes and also discuss the challenges ahead, with special reference to the Indian scenario.

Clinical Presentation and Outcomes of Stage III or Stage IV Retinoblastoma in 80 Asian Indian Patients

PURPOSE

To describe the clinical features and outcomes of patients with stage III or IV retinoblastoma.

METHODS

This was a retrospective study of 80 patients.

RESULTS

Based on the International Retinoblastoma Staging System (IRSS), the tumors (n = 81) belonged to stage IIIa (n = 38, 47%), IIIb (n = 1, 1%), IVa2 (n = 10, 12%), IVb1 (n = 14, 17%), and IVb3 (n = 18, 22%). Of 80 patients, 42 (53%) were compliant to treatment and 38 (47%) were non-compliant. All 38 patients who were non-compliant to treatment died of the disease at a mean duration of 13 months from diagnosis. Of the 42 patients compliant to treatment, 22 (52%) died before completion of treatment. Twenty patients with stage III disease (25%) could complete the multimodal treatment and 17 (71%) were alive and well at a median follow-up duration of 77 months.

CONCLUSIONS

Compliant multimodality treatment is beneficial in patients with IRSS stage III disease. IRSS stage IV retinoblastoma has poor prognosis despite treatment. [J Pediatr Ophthalmol Strabismus. 2017;54(3):177-184.].

Retinoblastoma: achieving new standards with methods of chemotherapy

The management of retinoblastoma (RB) has dramatically changed over the past two decades from previous radiotherapy methods to current chemotherapy strategies. RB is a remarkably chemotherapy-sensitive tumor. Chemotherapy is currently used as a first-line approach for children with this malignancy and can be delivered by intravenous, intra-arterial, periocular, and intravitreal routes. The choice of route for chemotherapy administration depends upon the tumor laterality and tumor staging. Intravenous chemotherapy (IVC) is used most often in bilateral cases, orbital RB, and as an adjuvant treatment in high-risk RB. Intra-arterial chemotherapy (IAC) is used in cases with group C or D RB and selected cases of group E tumor. Periocular chemotherapy is used as an adjunct treatment in eyes with group D and E RB and those with persistent/recurrent vitreous seeds. Intravitreal chemotherapy is reserved for eyes with persistent/recurrent vitreous seeds. In this review, we describe the various forms of chemotherapy used in the management of RB. A database search was performed on PubMed, using the terms “RB,” and “treatment,” “chemotherapy,” “systemic chemotherapy,” “IVC,” “IAC,” “periocular chemotherapy,” or “intravitreal chemotherapy.” Relevant English language articles were extracted, reviewed, and referenced appropriately.

Multimodal Therapy for Stage III Retinoblastoma (International Retinoblastoma Staging System): A Prospective Comparative Study

PURPOSE

To compare the efficacy of 2 chemotherapeutic drug combinations as part of multimodal therapy for orbital retinoblastoma.

DESIGN

Prospective, comparative, study.

PARTICIPANTS

Patients with stage III retinoblastoma (International Retinoblastoma Staging System).

METHODS

Demographic and clinical features were recorded at presentation. Treatment consisted of a multimodal protocol with neoadjuvant chemotherapy, enucleation, orbital external-beam radiotherapy, and adjuvant chemotherapy. For chemotherapy, patients were randomized into 2 groups: group A patients were treated with vincristine, etoposide, and carboplatin (VEC) and group B patients were treated with carboplatin and etoposide, alternating with cyclophosphamide, idarubicin, and vincristine. Treatment outcomes and adverse effects were recorded. Efficacy parameters were compared between the groups.

MAIN OUTCOME MEASURES

Survival probability, cause of death, and chemotherapy-related toxicity.

RESULTS

A total of 54 children were recruited (27 in each group). The mean ± SD follow-up was 21.3±11.34 months. The overall Kaplan-Meier survival probability was 80% (95% confidence interval [CI], 0.67-0.89) and 42% (95% CI, 0.24-0.59) at 1 year and 4 years, respectively. There were 9 deaths in group A and 15 deaths in group B. The Kaplan-Meier survival probability at 1 year was similar between the groups: 81% (95% CI, 0.60-0.91) and 79% (95% CI, 0.58-0.9) for groups A and B, respectively. At 4 years, the survival probability for group A was higher (63% [95% CI, 0.41-0.79] vs. 25% [95% CI, 0.08-0.46] for groups A and B, respectively), with a strong trend of better survival in group A over time (P = 0.05). The major cause of death was central nervous system relapse (8 patients in group A and 7 patients in group B). Two patients in group B died of sepsis after febrile neutropenia. Grade 3 and grade 4 hematologic toxicities were more common in group B, with a significant difference in grade 4 neutropenia (P = 0.002).

CONCLUSIONS

This study compared the outcomes of VEC chemotherapy with a 5-drug combination of etoposide and carboplatin, alternating with cyclophosphamide, idarubicin, and vincristine, for stage III retinoblastoma. The VEC combination was found to be more effective and may be recommended as neoadjuvant and adjuvant chemotherapy.

Chemotherapy in Retinoblastoma: Current Approaches

Retinoblastoma (RB) is the most common childhood malignant intraocular tumor. Although enucleation and external beam radiotherapy have been historically used, today the most commonly used eye-sparing approach is chemotherapy. Chemotherapy can be used in both intraocular and extraocular RB cases. Chemotherapeutic agents may be applied in different ways, including systemic, subconjunctival, intra-arterial and intravitreal routes. The main purposes of application of systemic therapy are to reduce the tumor size for local treatment (chemoreduction), or to reduce the risk of metastasis after enucleation surgery (adjuvant therapy). Intra-arterial chemotherapy with the current name “super-selective intra-arterial infusion therapy” could be applied as primary therapy in tumors confined to the retina or as a secondary method in tumor recurrence. The most important advantage of intra-arterial therapy is the prevention of systemic chemotherapy complications. Intravitreal chemotherapy is administered in the presence of persistent or recurrent vitreous seeding. The term “extraocular RB” includes orbital invasion and metastatic disease. Current treatment for orbital invasion is neoadjuvant chemotherapy followed by surgical enucleation and adjuvant chemotherapy and radiotherapy after surgery. In metastatic disease, regional lymph node involvement, distant metastases, and/or central nervous system (CNS) involvement may occur. Among them, CNS involvement has the worst prognosis, remaining at almost 100% mortality. In metastatic disease, high-dose salvage chemotherapy and autologous hematopoietic stem cell rescue therapy are the possible treatment options; radiotherapy could also be added to the protocol according to the side of involvement.

Retinoblastoma: An overview

Retinoblastoma is the most common intraocular malignancy in children, with a reported incidence ranging from 1 in 15,000 to 1 in 18,000 live births. It is second only to uveal melanoma in the frequency of occurrence of malignant intraocular tumors. Pawius described retinoblastoma as early as in 1597 referred to the tumor as fungus hematodes and suggested enucleation as the primary mode of management. The discovery of ophthalmoloscope in 1851 facilitated recognition of specific clinical features of retinoblastoma. Initially thought to be derived from the glial cells, it was called a glioma of the retina by Virchow (1864). Flexner (1891) and Wintersteiner (1897) believed it to be a neuroepithelioma because of the presence of rosettes. Later, there was a consensus that the tumor originated from the retinoblasts and the American Ophthalmological Society officially accepted the term retinoblastoma in 1926. Retinoblastoma was associated with near certain death just over a century ago. There has been a dramatic change in the overall management of retinoblastoma in the last decade. Specific genetic protocols have been able to make pre natal diagnosis of retinoblastoma. Early diagnosis and advancements in focal therapy have resulted in improved eye and vision salvage. This article explains the complexity of retinoblastoma, genetic association, clinical features, management and prognosis.

Retinoblastoma and treatment: A current evaluation of advanced therapy

Retinoblastoma is the most common primary childhood ocular tumor, affecting nearly 3.5 per million children worldwide. A mutation in the RB1 gene, which presents as either germline or sporadic, along with additional mutational events, promote neoplastic growth in the retina. Fortunately, current treatment protocols result in success rates approaching 99% at specialized centers, with many children maintaining useful vision. Overall, treatment is guided by aggressiveness and size, and is classified by systems such as the Reese-Ellsworth System and the International Classification of Retinoblastoma. Due to advances in chemotherapy protocols combined with use of focal laser consolidation, treatment paradigms have shifted from enucleation to external beam radiation therapy to chemotherapy as globe-salvaging therapies. Smaller, less complex tumors may be controlled by plaque radiotherapy or focal laser ablative therapy. However, larger and more complex tumors, such as those that have vitreous or subretinal seeding, require methods of chemoreduction combined with focal consolidation to yield better outcomes. Standard chemotherapy protocols utilize vincristine, etoposide, and carboplatin with or without cyclophosphamide. Finally, there has been a recent push in local treatments for retinoblastoma to minimize systemic toxicities. These modalities include intravitreal or subconjunctival injections and more recently, direct chemotherapy administration into the ophthalmic artery. As a result, enucleation is used less often, but remains an important treatment for the most aggressive, refractory cases. The advancement of retinoblastoma treatment looks promising; however, worldwide access to these treatments and the lack of long-term follow-up of new local treatment modalities constitute current and future challenges.

Distant metastatic retinoblastoma without central nervous system involvement

Retinoblastoma is the most common intraocular malignancy in children, with a reported incidence ranging from 1 in 15,000 to 1 in 18,000 live births. Metastatic retinoblastoma is rare in developed countries, with a reported range from 4.8% in the United States to 5.8% in the United Kingdom. However, the frequency reported from developing countries varies from 9 to 11% at presentation. The mortality is very high owing to late presentations, delayed diagnosis compounded by socio-economic factors. The management of metastatic retinoblastoma is evolving, but it is still a challenge in pediatric oncology. We present a case of an extensive skeletal metastasis that initially presented as a massive orbital retinoblastoma.

First-year experience of chemotherapy for advanced retinoblastoma in Tanzania: disease profile, outcomes, and challenges in 2008

PURPOSE

To examine the profile of retinoblastoma in a national tertiary referral center in Tanzania and to report first-year outcomes of its treatment using chemotherapy.

METHODS

All patients with retinoblastoma referred in 2008 were included. Disease was classified on clinical grounds as ocular, orbital, or metastatic. Those with ocular and orbital disease received chemotherapy. Remission was the main outcome measure and defined as absence of disease at the end of treatment.

RESULTS

In 2008, 37 patients (20 males and 17 females) with retinoblastoma were referred to Ocean Road Cancer Institute. The mean delay from the first sign of disease to presentation at hospital was 10.4 ± 8.7 months. Disease was ocular in 32% (12 of 37), orbital in 57% (21 of 37), and metastatic in 11% (4 of 37). Of those with ocular disease, 67% (8 of 12) completed chemotherapy and all (8 of 8) achieved remission. In contrast, 48% (10 of 21) with orbital disease completed chemotherapy and only 50% (5 of 10) achieved remission. The difference in outcome between the groups was statistically significant (P = .001, Fisher exact test).

CONCLUSION

The profile of retinoblastoma in Tanzania is skewed toward severe invasive disease. Despite the introduction of chemotherapy, further improvements in mortality and morbidity can only be achieved through emphasis on early detection.

Outcome, pathologic findings, and compliance in orbital retinoblastoma (International Retinoblastoma Staging System stage III) treated with neoadjuvant chemotherapy: a prospective study

PURPOSE

The present study prospectively evaluated outcome, pathologic findings, and compliance in orbital retinoblastoma patients (International Retinoblastoma Staging System [IRSS] stage III).

DESIGN

Prospective study and case series.

PARTICIPANTS

Twenty-eight consecutive IRSS stage III retinoblastoma patients were enrolled prospectively in the study after ethics committee approval and written informed consent.

METHODS

Planned therapy for patients included treatment with a uniform protocol consisting of neoadjuvant chemotherapy followed by enucleation, adjuvant radiotherapy, and chemotherapy. Prospective computerized data entry and telephone contact were undertaken to improve compliance, a major issue in treatment of orbital retinoblastoma.

MAIN OUTCOME MEASURES

Event-free survival (EFS) and overall survival (OS) were calculated using Kaplan-Meier survival analysis. The difference between groups was analyzed using the log-rank test.

RESULTS

Median follow-up was 14.75 months (range, 2.23-26.3 months). The OS for all patients was 40.4% and the EFS was 33.33% at a follow-up of 26.3 months. The median EFS and OS were 10.37 months and 15.73 months, respectively. At baseline, bilateral retinoblastoma predicted inferior EFS (P = 0.0006) and OS (P = 0.0081). Twenty-two of 28 patients underwent enucleation, and viable tumor was present in 21 of 22 enucleated specimens (95%). Neoadjuvant chemotherapy prevented orbital exenterations. Presence of tumor in the cut end of the optic nerve significantly correlated with inferior EFS (P = 0.012) and OS (P = 0.0098). Central nervous system metastasis was the most common site of relapse and death. The overall rate of compliance with treatment was 67.8% (19/28), which was twice the compliance rate at the authors' center before initiation of the present study.

CONCLUSIONS

There is a paucity of information in the literature on outcomes and pathologic findings after neoadjuvant chemotherapy in IRSS stage III retinoblastoma treated with a uniform treatment protocol, and as far as the authors are aware, there has been no prospective study. Neoadjuvant chemotherapy was able to avoid exenteration in all operated patients; however, residual viable tumor was present in 95% of enucleated specimens. Bilaterality and tumor in the optic nerve cut end after neoadjuvant chemotherapy were associated with inferior outcome. Compliance could be improved with computerized data entry and regular telephone contact.

Orbital retinoblastoma: Present status and future challenges - A review

Orbital retinoblastoma is a catastrophic event traditionally carrying a dismal prognosis. Although its incidence is less in the developed countries it continues to be one of the major diagnosis at presentation in the developing world. Orbital retinoblastoma encompasses a wide range of distinct clinical entities with varying tumor load. There are no standard treatment protocols as of now but the current preferred management is multimodal with a combination of initial high-dose chemotherapy, surgery, external beam radiotherapy and prolonged chemotherapy for twelve cycles. In spite of progress on all fronts including surgical, medical, diagnostic, genetic and rehabilitative with improving survival rates, however, lack of access to medical facilities, lack of education about the need for early medical attention and cultural resistance to enucleation continue to contribute to an epidemic of extra ocular disease at diagnosis in the developing world. This review introduces the various terminologies used in the spectrum of orbital retinoblastoma, discusses in details the clinical aspects and management protocols, current status and the future directions.

In vitro evaluation of a targeted and sustained release system for retinoblastoma cells using Doxorubicin as a model drug

PURPOSE

The objective of this study was to develop a novel folate receptor-targeted drug delivery system for retinoblastoma cells using doxorubicin (DOX) as a model drug.

METHODS

Biodegradable DOX-loaded poly(d,l-lactide-co-glycolide)-poly(ethylene glycol)-folate (PLGA-PEG-FOL) micelles (DOXM) were prepared with various solvents (dimethylsulfoxide, acetone, and dimethylformamide). The effects of solvents on entrapment efficiency, particle size, and polydispersity were examined. The effects of thermosensitive gel structure on the release of DOX from the DOXM were also studied. Qualitative and quantitative uptake studies of DOX and DOXM were carried out in Y-79 cell line. Cytotoxicity studies of DOXM were performed on Y-79 cells.

RESULTS

Based on size, polydispersity, and entrapment efficiency, dimethylformamide was found to be the most suitable solvent for the preparation of DOXM. Dispersion of DOXM in PLGA-PEG-PLGA gel sustained drug release for a period of 2 weeks. Uptake of DOX was ∼4 times higher with DOXM than DOX in Y-79 cells overexpressing folate receptors. This was further confirmed from the quantitative uptake studies. DOXM exhibited higher cytotoxicity in Y-79 cells when compared with pure DOX.

CONCLUSION

These polymeric micellar systems suspended in thermosensitive gels may provide sustained and targeted delivery of anticancer agents to retinoblastoma cells following intravitreal administration.

Retinoblastoma - current treatment and future direction

Retinoblastoma is the commonest primary ocular malignancy of childhood. There are two forms - heritable and non heritable. Heritable retinoblastoma is a cancer susceptibility syndrome. Presentation is in the first few years of life, sometimes in the neonatal period. Early detection and prompt treatment can give cure rates up to 95% for intraocular tumours, but extraocular disease carries a very high mortality. The diagnosis is essentially clinical and biopsy is contraindicated due to the risk of extraocular spread. Treatment requires significant multidisciplinary input, with local ophthalmic treatment, systemic chemotherapy and external beam or plaque radiotherapy, or surgery to remove the affected eye. Screening of family members is essential for early detection. Lifelong surveillance of mutation carriers is needed due to the risk of second cancers. Newer treatment modalities including intra-arterial chemotherapy have been added to the therapeutic armamentarium in recent years.

Treatment and outcome of nonmetastatic extraocular retinoblastoma with a uniform chemotherapy protocol

Nonmetastatic extraocular retinoblastoma is a common entity in South-East Asia. We did a retrospective study of patients treated for isolated extraocular retinoblastoma, that is, International retinoblastoma staging system stages II and III, using a uniform chemotherapy protocol at our oncology center, between June 2003 and June 2008. Out of the 25 patients having nonmetastatic extraocular retinoblastoma, 6 were in stage II, and 19 in stage III. The probability of event-free survival was 0.54 at 18 months of follow-up with no significant difference between the 2 stages and the presence of optic nerve involvement; 11 out of 13 relapses were systemic. This is the largest case series of nonmetastatic extraocular retinoblastoma from South-East Asia.

Histopathologic risk factors in retinoblastoma in India

CONTEXT

The presence of histopathologic risk factors is associated with development of metastasis in a patient with retinoblastoma. Adjuvant chemotherapy administered to such patients decreases the risk of metastasis.

OBJECTIVE

To analyze the incidence of histopathologic risk factors in our patient population and the clinical predictors of such risk factors.

DESIGN

This is a retrospective case series, with review of clinical data and histopathologic slides, in 142 consecutive eyes enucleated for retinoblastoma between 1996 and 2002.

RESULTS

Histopathologic risk factors were present in 54.2% of 142 eyes enucleated for retinoblastoma and included infiltration of iris (7%), ciliary body (9%), choroid (40%), optic nerve lamina cribrosa (11%), retrolaminar optic nerve (17%), optic nerve to the line of transection (8%), sclera (9%), and extrascleral structures (6%). On univariate analysis, histopathologic risk factors correlated with age greater than 24 months at presentation and with glaucoma and iris neovascularization at presentation. On multivariate logistic regression analysis, age greater than 24 months and iris neovascularization correlated with infiltration of the choroid, while iris neovascularization correlated with infiltration of the retrolaminar optic nerve.

CONCLUSION

Histopathologic risk factors are present in a significant proportion of patients enucleated for retinoblastoma and have identifiable clinical predictors.

Outcomes of a two-drug chemotherapy regimen for intraocular retinoblastoma

BACKGROUND

Retinoblastoma is the most common intraocular tumor of childhood. Vision salvage rates in advanced cases are less than ideal, and the optimal treatment for intraocular retinoblastoma has not been established. We report the results of an institutional retinoblastoma treatment trial to determine the vision salvage rates and toxicity of a regimen combining carboplatin and etoposide with focal retinal therapy.

PROCEDURE

Twenty-nine patients diagnosed with retinoblastoma in 48 eyes were treated between 1992 and 2004 with at least six cycles of carboplatin and etoposide combined with focal retinal therapy.

RESULTS

The response rate of eyes after six cycles of chemotherapy was 85.4%. Twenty-two eyes were enucleated, but only seven eyes received EBRT. The vision salvage rate without EBRT was 82.6% for eyes with Reese-Ellsworth (R-E) groups I-IV tumors and 20% for eyes with R-E group V tumors. The vision salvage rate without EBRT for eyes with Murphree groups A and B tumors was 77.3% but was only 26.9% for eyes with groups C and D tumors. Acute side effects were minimal.

CONCLUSIONS

The combination of carboplatin and etoposide with focal therapy is a well-tolerated regimen that has acceptable vision salvage rates for R-E groups I-IV and Murphree groups A and B retinoblastoma. This combination avoids the use of EBRT and the toxicity of additional chemotherapy agents. However, patients with R-E group V and Murphree groups C and D retinoblastoma have poorer outcomes and require more intensive therapy.

Systemic metastasis following hyphema drainage in an unsuspected retinoblastoma

A 6-year-old girl had total hyphema and elevated left intraocular pressure following trivial trauma. B-scan with vector A-scan revealed vitreous opacities consistent with hemorrhage. The drained hyphema did not recur. A left vascular conjunctival mass and massive cervical lymphadenopathy occurred 7 months later. Biopsy revealed extraocular retinoblastoma and lymph node metastasis. Computed tomography showed an intraocular mass with intracranial extension. She died of metastatic disease despite intensive chemotherapy. Retinoblastoma should be suspected in a child with hyphema following trivial trauma.