Treatment results in patients with retinoblastoma and invasion to the cut end of the optic nerve

Outcomes of five cases of retinoblastoma with optic nerve invasion on imaging

PURPOSE

To investigate the timing of enucleation, treatment course, and outcome for retinoblastoma (RB) with optic nerve (ON) invasion on imaging.

STUDY DESIGN

Retrospective clinical study.

METHODS

Of the 160 patients with RB who presented to the National Center for Child Health and Development in Japan between 2005 and 2022, ON invasion on imaging at the initial presentation was seen in five patients. The clinical, computed tomography (CT), and magnetic resonance imaging (MRI) findings, and treatment courses were reviewed retrospectively.

RESULTS

MRI showed ON invasion in all five patients (three with unilateral RB, 2 with bilateral RB); in two patients CT detected no invasion. Enucleation was performed in four patients, three of whom underwent neoadjuvant therapy and one had a positive ON resection margin following the enucleation as initial treatment. One patient did not undergo enucleation due to cerebrospinal fluid dissemination. All enucleated patients underwent adjuvant chemotherapy. Four patients underwent radiotherapy. During follow-up (mean, 89.4 months), four patients survived and one died.

CONCLUSION

MRI is recommended to evaluate ON invasion and determine the timing of enucleation for RB. The appropriate choice of neoadjuvant or adjuvant therapy would be helpful to avoid radiotherapy for RB with ON invasion on imaging.

Retinoblastoma Outcomes Based on the 8th Edition American Joint Committee on Cancer Pathological Classification in 1411 Patients

PURPOSE

To evaluate the outcomes of retinoblastoma (RB) based on the 8th edition of the American Joint Committee on Cancer (AJCC) pathological classification in a global cohort of patients.

DESIGN

Retrospective, multicenter, intercontinental, collaborative study.

PARTICIPANTS

A total of 1411 patients.

INTERVENTION

Primary enucleation with or without adjuvant chemotherapy or radiotherapy.

MAIN OUTCOME MEASURES

Orbital tumor recurrence, tumor-related metastasis, and tumor-related death.

RESULTS

According to the 8th edition AJCC pathological classification, 645 eyes (46%) belonged to pathological T (pT)1, 164 (11%) to pT2, 493 (35%) to pT3, and 109 (8%) to pT4 categories. At a mean follow-up of 38 months (median, 35 months; < 1-149 months), orbital tumor recurrence was seen in 8 (1%), 5 (3%), 22 (4%), and 25 (23%) of pT1, pT2, pT3, and pT4 (P < 0.001) categories, respectively; tumor-related metastasis was seen in 7 (1%), 5 (3%), 40 (8%), and 46 (43%) of pT1, pT2, pT3, and pT4 (P < 0.001) categories, respectively; tumor-related death was seen in 12 (2%), 7 (4%), 64 (13%), and 64 (59%) of pT1, pT2, pT3, and pT4 (P < 0.001) categories, respectively. Multivariate Cox proportional hazards analysis of outcomes revealed pT category and adjuvant therapy as independent predictors of outcomes. Categories pT3b (P = 0.005), pT3c (P < 0.001), pT3d (P < 0.001), and pT4 (P < 0.001) had a greater hazard for orbital recurrence; categories pT2a (P = 0.015), pT3a (P < 0.001), pT3b (P < 0.001), pT3c (P < 0.001), pT3d (P < 0.001), and pT4 (P < 0.001) had a greater hazard for tumor-related metastasis; and categories pT2a (P = 0.068), pT2b (P = 0.004), pT3a (P < 0.001), pT3b (P < 0.001), pT3c (P < 0.001), pT3d (P < 0.001), and pT4 (P < 0.001) had a greater hazard for tumor-related death when compared with the pT1 category. Patients who did not receive adjuvant therapy had greater hazards of orbital tumor recurrence in categories pT3b (P = 0.005), pT3c (P = 0.003), and pT4 (P = 0.002); greater hazards of tumor-related metastasis in categories pT3a (P = 0.001), pT3b (P = 0.01), pT3c (P = 0.001), and pT4 (P = 0.007); and tumor-related death in categories pT3a (P < 0.001), pT3b (P = 0.009), pT3c (P = 0.018), and pT4 (P < 0.001) when compared with those who received adjuvant therapy.

CONCLUSIONS

The 8th edition AJCC pathological classification predicts outcomes in patients undergoing primary enucleation for RB, and adjuvant therapy is associated with a lower risk of orbital recurrence, tumor-related metastasis, and tumor-related death in the pT3 and pT4 categories.

FINANCIAL DISCLOSURE(S)

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

Evidence in Focus: The Sparse Landscape of Randomized Trials on Retinoblastoma Treatment

Background

Retinoblastoma, although rare, is one of the most common intraocular malignancies worldwide. Its prognosis has improved significantly in the past few decades, thanks to modern treatments, like systemic, intra-arterial, and intravitreal chemotherapy. However, regarding survival, there are significant differences between high- and low-income countries, eye salvage is still a challenge worldwide, and treatment-related toxicity needs to be carefully and sufficiently managed.

Summary

To appraise the strength of supporting evidence, we performed a systematic review of randomized controlled trials investigating any therapeutic protocol for retinoblastoma. Four trials with 174 participants (188 eyes) were eligible, all pertaining to different intravenous chemotherapy regimens. Vincristine, etoposide, and carboplatin (VEC) appear superior to a 5-drug combination for stage III retinoblastoma. Moreover, etoposide and carboplatin as neoadjuvant chemotherapy followed by thermochemotherapy seem to offer better local control than vincristine and carboplatin. However, increasing carboplatin dose in the VEC protocol failed to improve treatment efficacy.

Key Messages

Retinoblastoma is a success story of modern medicine. However, only intravenous chemotherapy has been studied through randomized trials, while evidence for the most novel retinoblastoma treatments has mainly stemmed from observational studies. International collaborations for multicenter randomized trials could overcome difficulties and increase certainty and precision in the field.

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.

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.

Long-term efficacy of enucleation combined with primary orbital implantation in children with retinoblastoma histopathological invasion of optic nerve

Objective

This study aimed to observe the long-term effect of enucleation combined with primary orbital implantation in children with histopathologic optic nerve invasive retinoblastoma (RB).

Methods

We retrospectively analyzed the clinical data and outcomes of children with RB optic nerve invasion confirmed by histopathology who underwent enucleation combined with primary orbital implantation between March 2010 and April 2014 in Beijing Tongren Hospital. The follow-up time ranged from 81 to 129 months, with a mean follow-up of 96 ± 14 months.

Results

A total of 59 children were included in this study. There were 32 males and 27 females; 52 children were affected in one eye and seven children in both eyes. The time from onset of symptoms to visit was between 3 days and 16 months, with a mean of 2.2 ± 2.8 months. The age at the of surgery was between 2 and 65 months, with an average of 24 ± 13 months. Patients were classified based on the degree of optic nerve invasion into four grades: grade 1 (invasion of prelaminar) in 28 cases, grade 2 (invasion of laminar) in 14 cases, grade 3 (invasion of retrolaminar but not reaching the optic nerve transection) in 16 cases, and grade 4 (invasion of the optic nerve transection) in 1 case. Post-operatively, all children were treated with 0–9 cycles of intravenous chemotherapy based on histopathology results from the removed eye. Of the 59 children, 13 had postoperative complications, and one died from recurrence. The survival rate was 98% (58/59). There was one case of orbital implant exposure, one of orbital cellulitis, six of enophthalmos and superior sulcus deformity, two of blepharoptosis, one of granuloma complicated with blepharoptosis, and one with a subconjunctival cyst.

Conclusion

For children with RB histopathologic invasion of the optic nerve, enucleation combined with primary orbital implantation reveals future potential treatment options when combined with a full course of intravenous chemotherapy.

Full-width postlaminar optic nerve tumor invasion of retinoblastoma as risk-factor for leptomeningeal spread of retinoblastoma. A case report and review of the literature

We present a 6-year-old boy with unilateral retinoblastoma of the left eye. MRI showed an intraocular tumor that extended into the optic nerve beyond the lamina cribrosa. The affected eye was enucleated and the optic nerve resection margin proved to be free. Following protocol, this patient received six courses of adjuvant systemic chemotherapy. Unfortunately, after 5 months this patient returned with the leptomeningeal spread of the tumor and died quickly thereafter.Histopathologic analysis of the enucleated eye and distal optic nerve revealed that the postlaminar tumor cells occupied the entire width of the optic nerve, extending all the way up to the pia mater, whereas, more often the tumor invasion is restricted to the center of the optic nerve. This was also visible on the MR images where contrast enhancement occupied the entire nerve width. A resection margin with tumor cells is recognized as a risk factor for metastasis, but perhaps the proximity of tumor cells to the leptomeninges should also be judged with caution as a potential increased risk for metastatic spread.

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

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

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.

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.

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.

How Eye-Preserving Therapy Affects Long-Term Overall Survival in Heritable Retinoblastoma Survivors

Purpose

Intraocular retinoblastoma is curable, but survivors with a heritable predisposition are at high risk for second malignancies. Because second malignancies are associated with high mortality, prognostic factors for second malignancy influence long-term overall survival. This study investigates the impact of all types of eye-preserving therapies on long-term survival in the complete German cohort of patients with heritable retinoblastoma.

Patients and Methods

Overall survival, disease staging using international scales, time period of diagnosis, and treatment type were analyzed in the 633 German children treated at the national reference center for heritable retinoblastoma.

Results

The 5-year overall survival of children diagnosed in Germany with heritable retinoblastoma between 1940 and 2008 was 93.2% (95% CI, 91.2% to 95.1%), but long-term mortality was increased compared with patients with nonheritable disease. Overall survival correlated with tumor staging, and 92% of patients were diagnosed with a favorable tumor stage (International Retinoblastoma Staging System stage 0 or I). Despite a 5-year overall survival of 97.4% (95% CI, 96.0% to 98.8%) in patients with stage 0 or I, only 79.5% (95% CI, 74.2% to 84.8%) of these patients survived 40 years after diagnosis. Long-term overall survival was reduced in children treated with eye-preserving radiotherapy compared with enucleation alone, and adding chemotherapy aggravated this effect.

Conclusion

The benefits of preserving vision must be balanced with the impact of eye-preserving treatments on long-term survival in heritable retinoblastoma, and the genetic background of the patient influences choice of eye-preserving treatment. Germline RB1 genetic analysis is important to identify heritable retinoblastoma among unilateral retinoblastoma cases. Eye-preserving radiotherapy should be carefully considered in patients with germline RB1 mutations. Life-long oncologic follow-up is crucial for all retinoblastoma survivors, and less detrimental eye-preserving therapies must be developed.

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.

Topotecan Delivery to the Optic Nerve after Ophthalmic Artery Chemosurgery

Extraocular retinoblastoma is a major challenge worldwide, especially in developing countries. Current treatment involves the administration of systemic chemotherapy combined with radiation, but there is a clear need for improvement of chemotherapy bioavailability in the optic nerve. Our aim was to study the ophthalmic artery chemosurgery (OAC) local route for drug delivery assessing ocular and optic nerve exposure to chemotherapy and to compare it to exposure after intravenous infusion (IV) of the same dose in an animal model. Topotecan was used as a prototype drug that is active in retinoblastoma and based on the extensive knowledge of its pharmacokinetics in preclinical and clinical settings. Five Landrace pigs received 4mg of topotecan via OAC as performed in retinoblastoma patients. At the end of the infusion, the eyes were enucleated, the optic nerve and retina were dissected, and the vitreous and plasma were separated. After recovery and a wash-out period, the animals received a 30-min IV infusion of topotecan (4 mg). The remaining eye was enucleated and tissues and fluids were separated. All samples were stored until quantitation using HPLC. A significantly higher concentration of topotecan in the optic nerve, vitreous, and retina was obtained in eyes after OAC compared to IV infusion (p<0.05). The median (range) ratio between topotecan concentration attained after OAC to IV infusion in the optic nerve, retina and vitreous was 84(54-668), 143(49-200) and 246(56-687), respectively. However, topotecan systemic exposure after OAC and IV infusion remained comparable (p>0.05). The median optic nerve-to-plasma ratio after OAC and IV was 44 and 0.35, respectively. Topotecan OAC delivery attained an 80-fold higher concentration in the optic nerve compared to the systemic infusion of the same dose with similar plasma concentrations in a swine model. Patients with retinoblastoma extension into the optic nerve may benefit from OAC for tumor burden by increased chemotherapy bioavailability in the optic nerve without increasing systemic exposure or toxicity.

Favorable outcome of alternate systemic and intra-arterial chemotherapy for retinoblastoma

The recent trend of treatment for retinoblastoma is to salvage the eye globes as well as achieving patients' survival. Intra-arterial chemotherapy (IAC) is one of the current standard treatment; however, it cannot exclude the risk of occult micrometastases in the central nervous system in advanced-stage retinoblastoma. Alternate fashion of intravenous chemotherapy (IVC) and IAC strategy was developed to increase the eye salvage rate and to reduce the metastatic risk. Between January 2012 and December 2014, 13 eyes of 12 patients with newly diagnosed retinoblastoma received alternate chemotherapy using IVC and IAC in Yonsei Cancer Center. Eye salvage rate was assessed by the eye preservation time, which was defined as the duration from the diagnosis to the time of enucleation. Total 13 eyes were classified according to the International Classification of Retinoblastoma (ICRB) as group B (n = 1, 7.7%), group C (n = 2, 15.4%), group D (n = 5, 38.5%), or group E (n = 5, 38.5%). IAC was performed, 3 to 5 times (median: 4 times) for each eye, total 54 times. Five to 15 courses (median: 8 courses) of systemic chemotherapy were performed in the patients. During the median follow-up period of 30.4 months, overall eye salvage rate was 63.9 ± 14.7%. All patients survived. The treatment was tolerable without significant complications. These results showed that primary alternate IVC-IAC was tolerable and effective for retinoblastoma.

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.

Management of retinoblastoma in children: current status

In recent years, there have been dramatic changes in the management of intraocular retinoblastoma. Intraocular retinoblastoma is a highly curable malignancy and current treatments are aimed to preserve vision while reducing the late effects such as treatment-induced secondary malignancies. The advent of intra-arterial chemotherapy changed the treatment paradigm from systemic treatment with chemotherapy to local treatment, and new questions emerged. While intra-arterial chemotherapy achieved encouraging results, only experience from major referral centers is reported, so its indications, advantages and risks are still to be elucidated. Many factors should be considered when choosing the appropriate conservative therapy. When the disease has extended outside the eye, the chances of cure are significantly lower and treatment should be tailored by the presence of pathology risk factors such as invasion of the choroid, the optic nerve, and the sclera. Adjuvant therapy is decided upon this information. Children with overt extraocular disease are treated with higher dose neoadjuvant therapy followed by delayed enucleation and adjuvant therapy.

Immunoreactivity of the 14F7 Mab raised against N-Glycolyl GM3 Ganglioside in retinoblastoma tumours

INTRODUCTION

The identification of molecules expressed selectively on the surface of retinoblastoma cells would allow applying targeted therapies. The Ganglioside, N-Glycolyl-GM3 (NeuGc-GM3), is an attractive candidate, as it has been detected in other paediatric neuroectodermic tumours, and it is not expressed in human normal tissues. The 14F7 antibody recognizes specifically the ganglioside NeuGc-GM3.

PURPOSE

To characterize the expression of NeuGc-GM3 in retinoblastoma cell lines and in retinoblastoma tumours using the 14F7 monoclonal antibody.

METHODS

We studied WERI-Rb1 and Y79 cell lines, 24 retinoblastoma primary tumours from unilateral and bilateral cases and two bone marrow biopsies from metastatic retinoblastoma. Tumours were classified into three groups: non-invasive (n = 13), invasive (n = 9) and metastatic (n = 2). Three eyes enucleated because of non-tumoural conditions were used as controls. Cell lines and tumour sections were studied by immunohistochemistry using the 14F7 antibody. NeuGc-GM3 expression was evaluated by analysing the percentage of positive tumoural cells and the staining intensity. These parameters were analysed comparatively among the three groups.

RESULTS

Both retinoblastoma cell lines showed immunoreactivity to NeuGc-GM3 but WERI-Rb1 presented higher intensity than Y79. All the tumours studied showed strong immunoreactivity to NeuGc-GM3 with no significant differences among groups. In both bone marrow specimens, NeuGc-GM3 immunoreactivity was observed in retinoblastoma cells. In bilaterally enucleated cases, NeuGc-GM3 immunoreactivity was not altered before and after chemotherapy. Non-tumoural retinas were negative.

CONCLUSIONS

NeuGc-GM3 is highly expressed in retinoblastoma cell lines, tumours and metastatic cells to the bone marrow, and it is not detectable in control eyes. There were no significant differences in the immunoreactivity to 14F7 among tumours from different disease stages. Its immunoreactivity did not change after chemotherapy.

Intraoperative sub-tenon injection increases optic nerve length transection during enucleation

PURPOSE

To determine the effect of sub-Tenon injection on the length of optic nerve resected during enucleation.

METHODS

Case-control laboratory study on 22 orbits of 11 unpreserved, fresh-frozen human cadavers. Each cadaver underwent a conventional enucleation technique on one side and an otherwise identical technique on the contralateral side that included sub-Tenon injection of 2.5 ml normal saline in each oblique quadrant. Resected optic nerve lengths were measured and compared using Student t tests.

RESULTS

The mean optic nerve length was 15.2 mm (range, 5.0-21.0 mm) in the sub-Tenon injection group and 11.3 mm (range, 5.0-19.0 mm) in control group (p = 0.015).

CONCLUSIONS

Sub-Tenon injection during enucleation allows for significantly longer optic nerve resection lengths in unpreserved, fresh-frozen human cadavers.

Long-term medical outcomes in survivors of extra-ocular retinoblastoma: the Memorial Sloan-Kettering Cancer Center (MSKCC) experience

BACKGROUND

Data on long-term outcomes of survivors of extra-ocular retinoblastoma are lacking. The authors sought to provide the first report characterizing long-term outcomes among survivors of extra-ocular retinoblastoma.

PROCEDURE

Retrospective analysis of long-term medical outcomes in 19 survivors of extra-ocular retinoblastoma treated between 1992 and 2009. Severity of outcomes was graded using Common Terminology Criteria for Adverse Events. All patients received intensive multimodality therapy for their extra-ocular disease after management of their primary intra-ocular disease, including conventional chemotherapy (n = 19, 100%), radiotherapy (n = 15, 69%), and/or high-dose chemotherapy with autologous stem cell transplant (n = 17, 89%).

RESULTS

The median follow-up was 7.8 years from diagnosis of extra-ocular retinoblastoma (range 2-17.8 years). The most common long-term non-visual outcomes were hearing loss (n = 15, 79%), short stature (n = 7, 37%), and secondary malignancies [SMN] (n = 6, 31%). Sixty-eight percent of survivors exhibited ≥2 non-visual long-term outcomes of any grade. Except short stature, which was not graded for severity, Grade 3-4 outcomes were limited to: ototoxicity (n = 8; n = 4 require hearing aids), SMNs (n = 6), and unequal limb length (n = 1). Five patients who developed SMNs carried a known RB1 mutation. SMNs developed at a median of 11.1 years after initial diagnosis; two patients died of their SMN. Long-term cardiac, pulmonary, hepatobiliary, or renal conditions were not identified in any survivors.

CONCLUSION

Long-term outcomes are commonly seen in extra-ocular retinoblastoma survivors but the majority are mild-moderate in their severity. Longer comprehensive follow-up is needed to fully assess treatment-related outcomes but the information collected to date may affect management decisions for children with extra-ocular disease.

Current therapy and recent advances in the management of retinoblastoma

Retinoblastoma is the most common intraocular malignancy in children. The survival of retinoblastoma patients and visual outcome has improved dramatically in the developed world. This can be attributed to early tumor recognition and advances in the management of retinoblastoma. Chemoreduction followed by adjuvant consolidative treatment has replaced external beam radiotherapy as the primary modality of treatment for intraocular retinoblastoma. Further, histopathological high-risk factors have been identified in enucleated eyes, allowing use of prophylactic chemotherapy to take care of possible micrometastasis. The survival in case of extraocular retinoblastoma is still low, and the reported survival rate ranges between 50% and 70%. In developing countries, the overall survival of retinoblastoma patients remains low, primarily due to a delayed presentation, resulting in larger proportions of extraocular disease compared with the developed world, where majority of the disease is intraocular. Greater efforts need to be directed toward early tumor recognition in order to improve the survival of retinoblastoma patients in the developing world. In this article, we provide an overview of the current clinical management of retinoblastoma.

"Retinoblastoma survival disparity": The expanding horizon in developing countries

The patients' survival for the most common intraocular tumor in children, retinoblastoma, has a wide spectrum among the world countries. This study was conducted to provide an overview of the retinoblastoma survival disparity worldwide by discussing the trends of patients' survival, as well as recent advances in the management of retinoblastoma. The design of this study was literature review and commentary. Selected articles from PubMed (except one) including both developing and developed countries regarding the patients' survival in retinoblastoma were considered and reviewed critically. An analysis of 47 articles was performed. In conclusion, in spite of an obvious contrast of retinoblastoma survival disparity in the world, the expanding horizons in developing countries are promising and continuing on all fronts and results are hope-inspiring.

Clinical presentation of retinoblastoma in a middle-income country

The presenting features of retinoblastoma in developing countries and their correlation with disease stage and patient survival are poorly known and they may be useful as background information for planning early diagnosis initiatives. Therefore, we undertook a retrospective review of 508 patients (467 evaluable, 296 unilateral) treated in Argentina from 1988 to 2008. Patients presented at an older age than reported from high-income countries [mean age 24 mo (range, 0 to 165 mo), 31 mo for unilateral (range, 0 to 165 mo), and 13.3 mo (range, 0 to 62 mo) for bilateral disease]. Leukocoria was the most common presenting sign (n=402, 86%). Strabismus was the only complaint in 25 (5.3%) patients. Forty-two patients (9%) presented with an enlarged eyeball and 37 (7.9%) with a red eye. Retinoblastoma was diagnosed in 22 (4.7%) asymptomatic children. These patients and those with strabismus alone were significantly younger and had a significantly better survival. Children presenting with enlarged eyeballs were significantly older and had significantly lower survival. In multivariable analysis older age and presentation with enlarged eyeballs were independently associated to advanced stage and mortality (P<0.001). Retinoblastoma is diagnosed in later stages in our setting and presentation with eye enlargement and increasing age at diagnosis correlate with worse outcome.

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.

Guidelines for imaging retinoblastoma: imaging principles and MRI standardization

Retinoblastoma is the most common intraocular tumor in children. The diagnosis is usually established by the ophthalmologist on the basis of fundoscopy and US. Together with US, high-resolution MRI has emerged as an important imaging modality for pretreatment assessment, i.e. for diagnostic confirmation, detection of local tumor extent, detection of associated developmental malformation of the brain and detection of associated intracranial primitive neuroectodermal tumor (trilateral retinoblastoma). Minimum requirements for pretreatment diagnostic evaluation of retinoblastoma or mimicking lesions are presented, based on consensus among members of the European Retinoblastoma Imaging Collaboration (ERIC). The most appropriate techniques for imaging in a child with leukocoria are reviewed. CT is no longer recommended. Implementation of a standardized MRI protocol for retinoblastoma in clinical practice may benefit children worldwide, especially those with hereditary retinoblastoma, since a decreased use of CT reduces the exposure to ionizing radiation.

Strategies to manage retinoblastoma in developing countries

Survival of retinoblastoma is >90% in developed countries but there are significant differences with developing countries in stage at presentation, available treatment options, family compliance, and survival. In low-income countries (LICs), children present with advanced disease, and the reasons are socioeconomic and cultural. In middle-income countries (MICs), survival rates are better (>70%), but there is a high prevalence of microscopically disseminated extraocular disease. Programs for eye preservation have been developed, but toxicity-related mortality is higher. Although effective treatment of microscopically extraocular disease improved the outcome, worldwide survival will be increased only by earlier diagnosis and better treatment adherence.

Results of a prospective study for the treatment of unilateral retinoblastoma

BACKGROUND

Few prospective studies about the management of unilateral retinoblastoma with pathology risk factors (PRFs) have been published.

METHODS

Patients (n = 114) were divided into four groups: Group 1 (initial chemoreduction) (n = 17). Groups 2 and 3, included patients initially enucleated with no, or lower risk PRFs: (n = 65) and with higher risk PRFs (n = 30), respectively. The later included postlaminar optic nerve involvement (PLONI) (n = 23), tumor at resection margin of optic nerve (n = 5) or isolated scleral invasion (n = 2). Group 3 received adjuvant chemotherapy including a total eight cycles of carboplatin and etoposide, alternating with cyclophosphamide, idarubicin, and vincristine. Orbital radiotherapy (45 Gy) was given to patients with invasion to the resection margin. Group 4 included patients with metastatic disease (n = 2). They were given neoadjuvant therapy followed by surgery and high-dose chemotherapy and autologous stem cell rescue.

RESULTS

Five-year event-free survival is 0.94 (1 for Group 1, 0.94 for Group 2, 0.96 for Group 3, and 0 for Group 4). Events included. Group 2: Systemic relapse (n = 2) and combined orbital and CNS relapse (n = 1). Relapsing patients had PLONI (n = 2) and isolated focal choroidal invasion (n = 1). Group 3: CNS relapse (n = 1) in a patient with tumor at the resection margin of optic nerve. Group 4: CNS relapse (n = 2). Only one relapsed patient survived. Eight of 17 eyes treated conservatively were preserved.

CONCLUSIONS

The survival of patients with unilateral retinoblastoma was excellent and 60% were spared from adjuvant treatment. Our intensive regimen was likely to be effective for prevention of metastasis in patients with higher risk PRFs.

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.