Treatment of retinoblastoma: Current status and future perspectives

Investigating druggable kinases for targeted therapy in retinoblastoma

Retinoblastoma (RB) is a childhood retinal neoplasm and commonly treated with cytotoxic chemotherapeutic agents. However, these therapeutic approaches often lead to diverse adverse effects. A precise molecular therapy will alleviate these side effects and offer better treatment outcomes. Over the years, kinases have become potential drug targets in cancer therapy. Hence, we aimed to investigate genetic alterations of putative kinase drug targets in RB. Targeted exome sequencing was performed on 35 RB tumors with paired blood samples using a gene panel consisting of 29 FDA-approved kinase genes. Single nucleotide variants were analyzed for pathogenicity using an in-house pipeline and copy number variations (CNVs) were detected by a depth of coverage and CNVPanelizer. The correlation between genetic changes and clinicopathological features was assessed using GraphPad Prism. Three somatic mutations, two in ERBB4 and one in EGFR were identified. Two of these mutations (ERBB4 c.C3836A & EGFR c.A1196T) were not reported earlier. CNV analysis revealed recurrent gains of ALK, MAP2K2, SRC, STK11, and FGFR3 as well as frequent losses of ATM, PI3KCA and ERBB4. Notably, nonresponsive tumors had a higher incidence of amplifications in clinically actionable genes such as ALK. Moreover, ALK gain and ATM loss were strongly correlated with optic nerve head invasion. In conclusion, our study revealed genetic alterations of druggable kinases in RB, providing preliminary insights for the exploration of kinase-targeted therapy in RB.

Retinoblastoma: An update on genetic origin, classification, conventional to next-generation treatment strategies

The most prevalent paediatric vision-threatening medical condition, retinoblastoma (RB), has been a global concern for a long time. Several conventional therapies, such as systemic chemotherapy and focal therapy, have been used for curative purposes; however, the search for tumour eradication with the least impact on surrounding tissues is still ongoing. This review focuses on the genetic origin, classification, conventional treatment modalities, and their combination with nano-scale delivery systems for active tumour targeting. In addition, the review also delves into ongoing clinical trials and patents, as well as emerging therapies such as gene therapy and immunotherapy for the treatment of RB. Understanding the role of genetics in the development of RB has refined its treatment strategy according to the genetic type. New approaches such as nanostructured drug delivery systems, galenic preparations, nutlin-3a, histone deacetylase inhibitors, N-MYC inhibitors, pentoxifylline, immunotherapy, gene therapy, etc. discussed in this review, have the potential to circumvent the limitations of conventional therapies and improve treatment outcomes for RB. In summary, this review highlights the importance and need for novel approaches as alternative therapies that would ultimately displace the shortcomings associated with conventional therapies and reduce the enucleation rate, thereby preserving global vision in the affected paediatric population.

Association of Neighborhood Opportunity With Severity of Retinoblastoma at Presentation

PURPOSE

To examine the relationship between the Child Opportunity Index (COI) and severity of retinoblastoma at presentation.

DESIGN

Cross-sectional study.

METHODS

Children (age <18 years) treated for retinoblastoma at a tertiary care center between January 2000 and May 2023 were included. Residential census tract was used to determine the overall and domain-specific COI score for each child. Collected variables included age, sex, race/ethnicity, insurance type, and the International Classification of Retinoblastoma (ICRB) Group at initial examination. The primary outcome was Group D or E retinoblastoma at presentation. Mixed effects regression models were used to estimate the association of COI scores with disease severity at presentation.

RESULTS

This study included 125 children (51.2% male). Median age at diagnosis was 13 months (IQR, 5-24 months). One hundred nine (87.2%) children presented with Group D or E retinoblastoma and 33 (26.4%) resided in low or very low opportunity neighborhoods. Children residing in neighborhoods with low overall COI scores (OR, 1.62; 95% CI, 1.01-2.58; P = .044) and low education COI scores (OR, 1.77; 95% CI, 1.13-2.79; P = .013) were at increased odds of presenting with ICRB Group D or E retinoblastoma after adjusting for individual-level socioeconomic factors.

CONCLUSION

Children residing in low opportunity neighborhoods-particularly low education opportunity-more often presented with advanced stage retinoblastoma than children residing in neighborhoods with higher opportunity scores. Efforts to improve preventative vision care and access to eye specialty care for children residing in low-resource areas are needed to reduce existing disparities in retinoblastoma.

Advancements in the diagnosis, prognosis, and treatment of retinoblastoma

Retinoblastoma (RB) is a prevalent primitive intraocular malignancy in children, particularly in those younger than age 3 years. RB is caused by mutations in the RB1 gene. In developing countries, mortality rates for this type of cancer are still high, whereas industrialized countries have achieved a survival rate of >95%-98%. Untreated, the condition can be fatal, underscoring the importance of early diagnosis. The existing treatments primarily consist of surgery, radiotherapy, and chemotherapy. The detrimental effects of radiation and chemotherapeutic drugs have been documented as factors that contribute to increased mortality rates and negatively affect the quality of life for patients. MicroRNA (miRNA), a type of noncoding RNA, exerts a substantial influence on RB development and the emergence of treatment resistance by regulating diverse cellular processes. This review highlights recent developments in the involvement of miRNAs in RB. This encompasses the clinical significance of miRNAs in the diagnosis, prognosis, and treatment of RB. Additionally, this paper examines the regulatory mechanisms of miRNAs in RB and explores potential therapeutic interventions. This paper provides an overview of the current and emerging treatment options for RB, focusing on recent studies investigating the application of different types of nanoparticles for the diagnosis and treatment of this condition.

The survival analysis and feasibility study of Pars Plana Vitrectomy (PPV) in the treatment of retinoblastoma

PURPOSE

To analyze the safety and efficacy of Pars Plana Vitrectomy (PPV) as a treatment for retinoblastoma patients and to evaluate the feasibility.

METHODS AND PATIENTS

We collected 342 eyes who had PPV after systemic chemotherapy in our retrospective study, then analyze the 5-year overall survival and 5-year event-free survival rate, recurrence rate, and metastasis rate. The above data were used to evaluate the feasibility of PPV in the treatment of retinoblastoma.

RESULTS

The mean value of follow-up time was 62.9 months from PPV. Of all 342 eyes, 18% eyes underwent enucleation of the eyeball. Excluding Non-PPV related deaths eyes, the 5-year overall survival rates and event-free survival were 95% and 80%; the tumor recurrence rate and metastasis rate were approximately 26% and 1.2%, respectively; the mortality was 3.9%. And the incidence of high-risk pathological factors of enucleated eyes after PPV was 32%.

CONCLUSION

Our results suggest that Pars Plana Vitrectomy as a new approach to preserve the eyeball of RB children is feasible, especially for those patients who cannot be completely controlled by systemic chemotherapy or the tumors with vitreous seeds. Although the outcomes in our study are very optimistic, we also recommend an experienced eye surgeon to perform the operation and strictly control the indications for PPV surgery. And enough systemic chemotherapy is very important before and after surgery.

LEVEL OF EVIDENCE

Treatment study (Retrospective comparative study), III.

Therapeutic Targeting PLK1 by ON-01910.Na Is Effective in Local Treatment of Retinoblastoma

Cell cycle deregulation is involved in the pathogenesis of many cancers and is often associated with protein kinase aberrations, including the polo-like kinase 1 (PLK1). We used retinoblastoma, an intraocular malignancy that lacks targeted therapy, as a disease model and set out to reveal targetability of PLK1 with a small molecular inhibitor ON-01910.Na. First, transcriptomic analysis on patient retinoblastoma tissues suggested that cell cycle progression was deregulated and confirmed that PLK1 pathway was upregulated. Next, antitumor activity of ON-01910.Na was investigated in both cellular and animal levels. Cytotoxicity induced by ON-01910.Na was tumor specific and dose dependent in retinoblastoma cells, while nontumor cells were minimally affected. In three-dimensional culture, ON-01910.Na demonstrated efficient drug penetrability with multilayer cell death. Posttreatment transcriptomic findings revealed that cell cycle arrest and MAPK cascade activation were induced following PLK1 inhibition and eventually resulted in apoptotic cell death. In Balb/c nude mice, a safe threshold of 0.8 nmol intravitreal dosage of ON-01910.Na was established for intraocular safety, which was demonstrated by structural integrity and functional preservation. Furthermore, intraocular and subcutaneous xenograft were significantly reduced with ON-01910.Na treatments. For the first time, we demonstrated targetability of PLK1 in retinoblastoma by efficiently causing cell cycle arrest and apoptosis. Our study is supportive that local treatment of ON-01910.Na may be a novel, effective modality benefiting patients with PLK1-aberrant tumors.

Successful Treatment of Late Isolated Bone Metastasis in a Patient with Bilateral Retinoblastoma Using an Unconventional Method

Though survival in bilateral retinoblastoma (RB) has improved due to advancement in diagnostics and treatment modalities, children require long-term follow-ups for recurrence and second malignancies. We report a case of bilateral RB in a 7-month-old baby who was treated with chemotherapy, transpupillary thermotherapy, and periocular carboplatin for both eyes following which there was complete regression of tumour. Six and a half years after treatment, the child presented with metastatic recurrence of tumour in the left ulna. He was treated successfully with chemotherapy, extracorporeal radiation and reimplantation therapy. A less aggressive treatment approach for isolated bone relapse may be considered in selected cases.

Unilateral retinoblastoma; natural history and an age-based protocol in 248 patients

OBJECTIVES

We aimed to study the clinical state and prognosis of patients with unilateral retinoblastoma who were being treated at a paediatric comprehensive cancer centre in a limited-resource country, to assess the different phases of treatment and the success of different, more complex real-life models.

SUBJECTS

In this retrospective study, we created a snapshot of our retinoblastoma database for the period between 2007 and 2015. Patients whose data were included in the study were followed up until 2016. Out of a total of 744 screened patients, we included data of 248 patients who had been diagnosed with unilateral retinoblastoma.

RESULTS

As classified as per the International Retinoblastoma Classification, 1 patient presented with group A, 21 with group B, 39 with group C, 104 with group D and 83 with group E retinoblastoma. Chemotherapy was the initial line of treatment in 115 patients and enucleation in 133 others. Later, 141 patients (56.9%) required further management. Patients had a mean ocular survival time of 20.8 months. Nine patients developed extraocular disease at a later stage of management: five after upfront enucleation and four after neoadjuvant chemotherapy. Mean overall survival time stood at 90.2 months. Four and three deaths were recorded in groups D and E, respectively. A single patient died in the initial chemotherapy arm, while six passed away in the initial enucleation arm.

CONCLUSION

Our study highlights the importance of initial chemotherapy and close follow-up after enucleation of classes D and E affected eyes even in absence of germline mutations.

Update on the Treatment of Retinoblastoma

Retinoblastoma (Rb) is the most common pediatric ocular malignancy and accounts for 2% of all childhood cancers. Rb is initiated by a mutation of the RB1 tumor suppressor gene and occurs in 2 forms: 1) unilateral and unifocal, characterized by a single tumor in 1 eye, and 2) bilateral or unilateral, multifocal Rb with multiple tumor foci in 1 or both eyes. Rb is a disease of young children and if left untreated can result in visual morbidity as well as systemic mortality. Fortunately, because of the greater availability of genetic testing and earlier diagnosis, novel targeted therapies, and multimodal treatment approaches, disease-free survival rates and visual prognoses have improved dramatically. Current efforts to expand the accessibility of the newest Rb treatments aim to improve Rb outcomes worldwide. In this article, we will review the clinical presentation, diagnosis, and management of Rb, with a focus on the newest treatment approaches.

Characteristics and Survival Outcomes of Second Primary Cancers in Long-term Retinoblastoma Survivors

PURPOSE

Retinoblastoma (RB) is the most common intraocular cancer and is associated with lifelong risks of developing a second primary cancer, especially in patients with hereditary RB and/or childhood exposure to radiotherapy.

METHODS

The study included all consecutive patients with a history of RB treated for a second primary cancer during 1994-2018. Patient demographics and characteristics of the primary RB and second primary cancer were examined. The associations among radiation or chemotherapy exposure as a treatment for RB, unilateral versus bilateral status, types and multiplicity of second primary cancers, and survival after diagnosis of second primary cancer were analyzed.

RESULTS

A wide spectrum of second primary cancer types was identified from 62 eligible patients (30 males and 32 females), including sarcoma, breast cancer, various skin cancers, gastrointestinal and genitourinary cancers, and endocrine cancers. Of all patients who had second primary cancers, 40 patients (65%) had bilateral RB and 17 patients (27%) had unilateral RB. Thirty-five patients (56%) who developed second primary cancers received radiation therapy during childhood as the treatment of RB, and 17 patients (27%) received chemotherapy for the treatment of RB. The 5-year and 10-year survival rates for RB patients diagnosed with a second primary cancer were 54.0% and 36.0%, respectively. The median age of onset of second primary cancer among RB survivors was 36.6 years.

CONCLUSIONS

In contrast to previous studies, we found a broader spectrum of second primary cancer types. All RB survivors, regardless of unilateral or bilateral status, should undergo strict cancer surveillance particularly as they approach the fourth decade of life.

lncRNA FEZF1‑AS1 promotes migration, invasion and epithelial‑mesenchymal transition of retinoblastoma cells by targeting miR‑1236‑3p

Long non-coding RNAs (lncRNAs) and microRNAs (miRs) have been reported to regulate disease progression in numerous types of disease, including retinoblastoma (Rb). Therefore, the present study aimed to investigate the effects of the lncRNA FEZ family zinc finger 1 antisense RNA 1 (FEZF1-AS1) on Rb and to determine its possible mechanism of action. Reverse transcription-quantitative PCR and western blot analysis were conducted to detect the gene or protein expression. Cell Counting Kit-8, wound healing and transwell invasion assays were performed to estimate the capabilities of cell viability, invasion and migration. The potential association between FEZF1-AS1 and miR-1236-3p in Y79 cells was measured via dual-luciferase reporter assay. The results of the present study revealed that the levels of FEZF1-AS1 were significantly upregulated in different Rb cell lines, with the most prominent upregulation observed in Y79 cells. In addition, the cell viability, invasive and migratory abilities, and the ability to undergo epithelial-mesenchymal transition (EMT), were significantly inhibited following the transfection of short hairpin RNA (shRNA)-FEZF1-AS1 into Y79 cells. Further experimental validation confirmed that miR-1236-3p may be a direct target of FEZF1-AS1. Notably, the miR-1236-3p inhibitor was discovered to reverse the inhibitory effects of shRNA-FEZF1-AS1 on cell viability, invasion, migration and EMT. In conclusion, the findings of the present study suggested that lncRNA-FEZF1-AS1 may promote the viability, migration, invasion and EMT of Rb cells by modulating miR-1236-3p.

HSV‑TK/GCV can induce cytotoxicity of retinoblastoma cells through autophagy inhibition by activating MAPK/ERK

Retinoblastoma is an severe ophthalmic disease and the most common type intraocular malignant tumor, particularly in infants. Currently, few drugs and therapies are available. Gene therapy has been considered to be a potential treatment to cure cancer effectively and Herpes simplex virus type 1 thymidine kinase/ganciclovir (HSV-TK/GCV) is one type of suicide gene therapy that has been extensively studied. Numerous in vitro and in vivo studied have shown that this system can kill tumor cells, including liver and lung cancer cells. GCV is used as an antiviral drug, and the thymidine kinase, HSV-TK can phosphorylate GCV to GCV-TP, a competitive inhibitor of DNA synthesis, instead of guanine-5′-triphosphate in the process of DNA synthesis. This process prevents DNA chain elongation causing cell death via apoptosis. However, the toxic effects of HSV-TK/GCV on retinoblastoma cells remain unknown, and the molecular mechanisms of its therapeutic effects have not been fully elucidated. Our results suggest that HSV-TK/GCV can significantly cause the death of retinoblastoma cell lines, HXO-RB44 and Y79. Further studies have reported that this cell death is induced by the inhibition of autophagy by activating the MAPK/ERK (mitogen-activated protein kinase/ERK) signaling pathway. The mTOR inhibitor Torin1 can partially block the toxic effects of HSV-TK/GCV on HXO-RB44 cells. The above results demonstrate that the mechanism undertaken by HSV-TK/GCV to exhibit therapeutic effects mechanism may inhibit autophagy by activating MAPK/ERK. The findings of the present study may provide novel insight for the exploration of HSV-TK/GCV in the treatment of retinoblastoma.

Ovarian tissue cryopreservation in young females through the Oncofertility Consortium's National Physicians Cooperative

AIM

To characterize the clinical indications of females (<15 years old) undergoing ovarian tissue cryopreservation (OTC) through the Oncofertility Consortium's National Physicians Cooperative (OC-NPC).

PATIENTS & METHODS

The clinical indications of 114 females who underwent OTC were classified, and their incidence was compared with childhood cancer databases.

RESULTS

Leukemias/myeloproliferative diseases/myelodysplastic diseases and hemoglobinopathies were the most prevalent oncologic and nononcologic indications for OTC, respectively. The frequencies of malignant bone tumors and soft tissue and other extraosseous sarcomas were higher in the OC-NPC cohort relative to the general population, while CNS/intracranial/intraspinal neoplasms, retinoblastoma and hepatic tumors were lower.

CONCLUSION

Those opting for OTC through the OC-NPC are at highest fertility risk, indicating that the appropriate patient populations are being identified. [Formula: see text].

Retinoblastoma in a pediatric oncology reference center in Southern Brazil

Background

Retinoblastoma (Rb) is the most common intraocular tumor diagnosed in children in Brazil. However, detailed information is lacking regarding patient clinical demographics. This study aimed to determine the clinical profile of patients with Rb who were treated in a public university hospital in southern Brazil from 1983 to 2012. Methods: Patients’ medical records were reviewed to retrospectively identify patients with a principal diagnosis of Rb. Rb was classified as hereditary or non-hereditary. Clinical staging was reviewed by an ophthalmologist. Statistical analysis was performed using SPSS.

Results

Of 165 patients with a diagnosis of Rb during this period, 140 were included in the study. Disease was unilateral in 65.0 % of patients, bilateral in 32.9 %, and trilateral in 2.1 %. The mean age at onset of the first sign/symptom was 18.1 month, and 35.7 % of patients were diagnosed during the first year of life. The most common presenting signs were leukocoria (73.6 %) and strabismus (20.7 %). The mean age at diagnosis was 23.5 months, and time to diagnosis was 5.4 months. In patients with clinical features of hereditary Rb, both onset of the first sign/symptom and diagnosis were at an earlier age than in patients without these features (12.3 vs 21.6 months [P = 0.001] and 15.9 vs 28.0 months [P < 0.001], respectively). However, there was no significant difference in overall survival between the two groups. Ocular stage at diagnosis was advanced in 76.5 % (Reese V) and 78.1 % (International Classification D or E). Of patients with unilateral and bilateral disease, 35.2 % and 34.8 %, respectively, had extraocular disease at diagnosis; 10.7 % had metastatic disease at diagnosis. Enucleation was observed in 88.1 % and exenteration in 11.9 % of patients; 93.6 % patients were followed until 2012, and 22.9 % relapsed. Overall survival was 86.4 %.

Conclusions

Most Rb diagnoses are still diagnosed in advanced stages of the disease, considerably reducing overall survival time and the rate of eye and vision preservation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0579-9) contains supplementary material, which is available to authorized users.

The Evolution of Radiation Therapy for Retinoblastoma: The MD Anderson Cancer Center Experience

Purpose

The role of radiation therapy (RT) for retinoblastoma (Rb) has significantly evolved from first-line to salvage therapy. The objectives of our study were to evaluate efficacy of proton RT (PRT) and other advanced RT techniques for Rb and to observe evolving trends in RT use.

Materials and Methods

An analysis of patients with Rb who received RT between 1990 and 2012 was conducted. Thirty-nine patients with 70 affected eyes were identified. Of these, 47 eyes were treated with RT with photon or electron RT (ERT), PRT, or brachytherapy (BRT). The clinical history, treatment details, and tumor outcomes were reviewed for all patients.

Results

Radiation therapy was first-line treatment in 14 eyes, second-line in 4, postoperative in 4, and salvage in 25. Median length of follow-up was 8 years for all patients, and 10, 3, and 5 years for ERT, PRT, and BRT, respectively. Overall survival was 97.4%. In total, 16 (34.0%) eyes required enucleation after RT. Median PRT dose was 36 Gy (RBE) (range, 36-45 Gy [RBE]), ERT dose was 45 Gy (range, 36-46 Gy), and BRT dose was 45 Gy (range, 36-45 Gy). A higher proportion of PRT patients (93.8%) than ERT patients (51.9%) were treated in the salvage setting (P < .01). Among patients with International Classification for Intraocular Retinoblastoma stage D and E disease, 6 of 11 (54.5%) ERT patients required enucleation and 5 of 13 (38.5%) PRT patients required enucleation.

Conclusion

This study represents a large series of patients treated with PRT, ERT, and BRT for Rb and reports favorable efficacy and toxicity. Patients treated with salvage PRT are typically heavily pretreated and have advanced disease. Despite more advanced disease, patients treated with PRT with lower RT doses achieve comparable salvage and enucleation-free rates to ERT. Chemoreduction followed by focal treatments should be standard of care when clinically feasible, with PRT considered in the salvage setting.

Spatiotemporal Patterns of Tumor Occurrence in Children with Intraocular Retinoblastoma

PURPOSE

To accurately map the retinal area covered by tumor in a prospectively enrolled cohort of children diagnosed with retinoblastoma.

METHODS

Orbital MRI in 106 consecutive retinoblastoma patients (44 bilateral) was analyzed. For MRI-visible tumors, the polar angle and angle of eccentricity of points defining tumor perimeter on the retina were determined by triangulation from images in three orthogonal planes. The centroid of the mapped area was calculated to approximate tumor origin, and the location and cumulative tumor burden were analyzed in relation to mutation type (germline vs. somatic), tumor area, and patient age at diagnosis. Location of small tumors undetected by MRI was approximated with fundoscopic images.

RESULTS

Mapping was successful for 129 tumors in 91 eyes from 67 patients (39 bilateral, 43 germline mutation). Cumulative tumor burden was highest within the macula and posterior pole and was asymmetrically higher within the inferonasal periphery. Tumor incidence was lowest in the superotemporal periphery. Tumor location varied with age at diagnosis in a complex pattern. Tumor location was concentrated in the macula and superonasal periphery in patients <5.6 months, in the inferotemporal quadrant of the posterior pole in patients 5.6-8.8 months, in the inferonasal quadrant in patients 8.8-13.2 months, and in the nasal and superotemporal periphery in patients >13.2 months. The distribution of MRI-invisible tumors was consistent with the asymmetry of mapped tumors.

CONCLUSIONS

MRI-based mapping revealed a previously unrecognized pattern of retinoblastoma localization that evolves with age at diagnosis. The structured spatiotemporal distribution of tumors may provide valuable clues about cellular or molecular events associated with tumorigenesis in the developing retina.

Retinoblastoma

Retinoblastoma is the most common neoplasm of the eye in childhood, and represents 3% of all childhood malignancies. Retinoblastoma is a cancer of the very young; two-thirds are diagnosed before 2 years of age and 95% before 5 years. Retinoblastoma presents in 2 distinct clinical forms: (1) a bilateral or multifocal, heritable form (25% of all cases), characterized by the presence of germline mutations of the RB1 gene; and (2) a unilateral or unifocal form (75% of all cases), 90% of which are nonhereditary. The treatment of retinoblastoma is multidisciplinary and is designed primarily to save life and preserve vision.

Cognitive function and social attainment in adult survivors of retinoblastoma: a report from the St. Jude Lifetime Cohort Study

BACKGROUND

Retinoblastoma has a 5-year survival rate exceeding 95%, yet little is known about long-term functional outcomes for these patients.

METHODS

Sixty-nine adult survivors of retinoblastoma (mean age, 33 years; mean years post-diagnosis, 31) who had enrolled in the St. Jude Lifetime Cohort Study completed clinical cognitive evaluations and questionnaires assessing adult social attainment. Scores on all cognitive measures were converted to z-scores (M = 0, SD = 1) using age-adjusted normative data. Multivariable linear regression analyses, adjusted for age at diagnosis and disease laterality, were used to examine associations between disease and treatment exposures and cognitive outcomes.

RESULTS

Retinoblastoma survivors performed within normative expectations across most cognitive domains. In multivariable models, adjusted for disease laterality, survivors diagnosed at ≤1 year of age performed significantly better on measures of short-term verbal memory (β = 0.87, P<.01), long-term verbal memory (β = 0.66, P = .02), verbal learning (β = 0.67, P = .02), and verbal reasoning abilities (β = 0.79, P<.01) compared with survivors diagnosed at >1 year of age. In multivariable models, restricted to bilateral survivors and adjusted for age at diagnosis, whole brain radiation exposure was significantly associated with poorer performance on tasks of short-term verbal memory (β = -0.003, P = .03) and long-term verbal memory (β = -0.003, P = .01). Reported social attainment was consistent with adult developmental expectations.

CONCLUSIONS

Adult survivors of retinoblastoma demonstrate few cognitive or social attainment deficits decades following diagnosis and treatment. Findings suggest the potential for neural reorganization following early insult to the visual system as well as vulnerability of the developing brain to low dose radiation exposure. Early intervention and rehabilitation will be important for these patients.

The modern role of radiation therapy in treating advanced-stage retinoblastoma: long-term outcomes and racial differences

PURPOSE/OBJECTIVE(S)

To evaluate the effects of various patient characteristics and radiation therapy treatment variables on outcomes in advanced-stage retinoblastoma.

METHODS AND MATERIALS

This was a retrospective review of 41 eyes of 30 patients treated with external beam radiation therapy between June 1, 1992, and March 31, 2012, with a median follow-up time of 133 months (11 years). Outcome measures included overall survival, progression-free survival, local control, eye preservation rate, and toxicity.

RESULTS

Over 90% of the eyes were stage V. Definitive external beam radiation therapy (EBRT) was delivered in 43.9% of eyes, adjuvant EBRT in 22% of eyes, and second-line/salvage EBRT in 34.1% of eyes. A relative lens sparing (RLS) technique was used in 68.3% of eyes and modified lens sparing (MLS) in 24.4% of eyes. Three eyes were treated with other techniques. Doses ≥45 Gy were used in 68.3% of eyes. Chemotherapy was a component of treatment in 53.7% of eyes. The 10-year overall survival was 87.7%, progression-free survival was 80.5%, and local control was 87.8%. White patients had significantly better overall survival than did African-American patients in univariate analysis (hazard ratio 0.09; 95% confidence interval 0.01-0.84; P=.035). Toxicity was seen in 68.3% of eyes, including 24.3% with isolated acute dermatitis.

CONCLUSIONS

External beam radiation therapy continues to be an effective treatment modality for advanced retinoblastoma, achieving excellent long-term local control and survival with low rates of treatment-related toxicity and secondary malignancy.

Proton radiation therapy for the treatment of retinoblastoma

PURPOSE

To investigate long-term disease and toxicity outcomes for pediatric retinoblastoma patients treated with proton radiation therapy (PRT).

METHODS AND MATERIALS

This is a retrospective analysis of 49 retinoblastoma patients (60 eyes) treated with PRT between 1986 and 2012.

RESULTS

The majority (84%) of patients had bilateral disease, and nearly half (45%) had received prior chemotherapy. At a median follow-up of 8 years (range, 1-24 years), no patients died of retinoblastoma or developed metastatic disease. The post-PRT enucleation rate was low (18%), especially in patients with early-stage disease (11% for patients with International Classification for Intraocular Retinoblastoma [ICIR] stage A-B disease vs 23% for patients with ICIR stage C-D disease). Post-PRT ophthalmologic follow-up was available for 61% of the preserved eyes (30 of 49): 14 of 30 eyes (47%) had 20/40 visual acuity or better, 7 of 30 (23%) had moderate visual acuity (20/40-20/600), and 9 of 30 (30%) had little or no useful vision (worse than 20/600). Twelve of 60 treated eyes (20%) experienced a post-PRT event requiring intervention, with cataracts the most common (4 eyes). No patients developed an in-field second malignancy.

CONCLUSIONS

Long-term follow-up of retinoblastoma patients treated with PRT demonstrates that PRT can achieve high local control rates, even in advanced cases, and many patients retain useful vision in the treated eye. Treatment-related ocular side effects were uncommon, and no radiation-associated malignancies were observed.

Retinoblastoma. Fifty years of progress. The LXXI Edward Jackson Memorial Lecture

PURPOSE

To review the progress made in understanding the genetic basis, molecular pathology, and treatment of retinoblastoma since the previous Jackson lecture on the topic was published 50 years ago.

DESIGN

Perspective based on personal experience and the literature.

METHODS

The literature regarding retinoblastoma was reviewed since 1963. Advances in understanding the biology and treatment of retinoblastoma provided context through the author's clinical, pathologic, and research experiences.

RESULTS

Retinoblastoma was first identified in the 1500s and defined as a unique clinicopathologic entity in 1809. Until the mid-1900s, knowledge advanced sporadically, with technological developments of ophthalmoscopy and light microscopy, and with the introduction of surgical enucleation, chemotherapy, and radiation therapy. During the last 50 years, research and treatment have progressed at an unprecedented rate owing to innovations in molecular biology and the development of targeted therapies. During this time period, the retinoblastoma gene was discovered; techniques for genetic testing for retinoblastoma were developed; and plaque brachytherapy, chemoreduction, intra-arterial chemotherapy, and intraocular injections of chemotherapeutic agents were successfully introduced.

CONCLUSIONS

Nearly all patients with retinoblastoma in developed countries can now be cured of their primary cancer--a remarkable achievement for a childhood cancer that once was uniformly fatal. Much of this success is owed to deciphering the role of the Rb gene, and the benefits of targeted therapies, such as chemoreduction with consolidation as well as intra-arterial and intravitreal chemotherapies. Going forward, the main challenge will be ensuring that access to care is available for all children, particularly those in developing countries.

High-dose chemotherapy with autologous stem cell rescue for treatment of retinoblastoma: report of five cases

RB is a primarily pediatric cancer arising from the retina, initiated by biallelic loss of the RB1 gene. We report five children with bilateral RB (n = 3), extra-ocular disseminated RB, or disseminated relapsed RB, who were treated with tandem high-dose chemotherapy and autologous stem cell rescue. All patients received at least 2.2 × 10(6) /kg CD34(+) (median, 3.9 × 10(6) /kg) cells. The preparative regimen for course 1 was carboplatin, thiotepa, etoposide, and for course 2, CM and melphalan. ANC of at least 0.5 × 10(9) /L occurred at a median of 11 days (range, 10-12) and 15 days (range, 12-16) after the first and second procedure, respectively. Platelet engraftment occurred at a median of 13 days (range, 12-17) and 15 days (range, 14-22) after the first and second procedure, respectively. All of the five patients treated remain alive and disease free at the last follow-up time, ranging between 21 and 44 months after completion of autologous transplant. Additional therapy was required in one patient, in whom enucleation had to be performed because of early disease relapse, refractory to local therapy. Intensification of chemotherapy with repeated high-dose chemotherapy and autologous rescue appears an acceptable choice in selected cases with bilateral or extra-ocular disease, either recurrent or refractory.

Inhibition of hypoxia inducible factor 1α by siRNA-induced apoptosis in human retinoblastoma cells

Hypoxia, which activates the hypoxia inducible factor 1α (HIF-1α), is an essential feature of retinoblastoma (RB) and contributes to poor prognosis and resistance to conventional therapy. In this study, the effect of HIF-1α knockdown by small interfering RNA (siRNA) on cell proliferation, apoptosis, and apoptotic pathways of human Y-79 RB cells was first investigated. Exposure to hypoxia induced the increased expression of HIF-1α both in mRNA and protein levels. Then, knockdown of HIF-1α by siRNAHIF-1α resulted in inhibition of cell proliferation and induced cell apoptosis in human Y-79 RB cells under both normoxic and hypoxic conditions, with hypoxic conditions being more sensitive. Furthermore, knockdown of HIF-1α could enhance hypoxia-induced slight increase of Bax/Bcl-2 ratio and activate caspase-9 and caspase-3. These results together indicated that suppression of HIF-1α expression may be a promising strategy for the treatment of human RB in the future.

Targeted expression of suicide gene by tissue-specific promoter and microRNA regulation for cancer gene therapy

In order to realise the full potential of cancer suicide gene therapy that allows the precise expression of suicide gene in cancer cells, we used a tissue specific Epithelial cell adhesion molecule (EpCAM) promoter (EGP-2) that directs transgene Herpes simplex virus–thymidine kinase (HSV-TK) expression preferentially in EpCAM over expressing cancer cells. EpCAM levels are considerably higher in retinoblastoma (RB), a childhood eye cancer with limited expression in normal cells. Use of miRNA regulation, adjacent to the use of the tissue-specific promoter, would provide the second layer of control to the transgene expression only in the tumor cells while sparing the normal cells. To test this hypothesis we cloned let-7b miRNA targets in the 3’UTR region of HSV-TK suicide gene driven by EpCAM promoter because let-7 family miRNAs, including let-7b, were found to be down regulated in the RB tumors and cell lines. We used EpCAM over expressing and let-7 down regulated RB cell lines Y79, WERI-Rb1 (EpCAM ^+ve/let-7b^{down-regulated}), EpCAM down regulated, let-7 over expressing normal retinal Müller glial cell line MIO-M1(EpCAM ^−ve/let-7b^up-regulated), and EpCAM up regulated, let-7b up-regulated normal thyroid cell line N-Thy-Ori-3.1(EpCAM ^+ve/let-7b^up-regulated) in the study. The cell proliferation was measured by MTT assay, apoptosis was measured by probing cleaved Caspase3, EpCAM and TK expression were quantified by Western blot. Our results showed that the EGP2-promoter HSV-TK (EGP2-TK) construct with 2 or 4 copies of let-7b miRNA targets expressed TK gene only in Y79, WERI-Rb-1, while the TK gene did not express in MIO-M1. In summary, we have developed a tissue-specific, miRNA-regulated dual control vector, which selectively expresses the suicide gene in EpCAM over expressing cells.

Relevance of historical therapeutic approaches to the contemporary treatment of pediatric solid tumors

Children with solid tumors, most of which are malignant, have an excellent prognosis when treated on contemporary regimens. These regimens, which incorporate chemotherapeutic agents and treatment modalities used for many decades, have evolved to improve relapse-free survival and reduce long-term toxicity. This review discusses the evolution of the treatment regimens employed for management of the most common solid tumors, emphasizing the similarities between contemporary and historical regimens. These similarities allow the use of historical patient cohorts to identify the late effects of successful therapy and to evaluate remedial interventions for these adverse effects.

Efficacy of vincristine and carboplatin as chemo-reduction for advanced bilateral retinoblastoma, the Saudi experience

PURPOSE

To evaluate the efficacy of a 2-drug chemotherapy regimen without external-beam radiotherapy (EBRT) and/or without enucleation in bilateral retinoblastoma.

METHODS

From 1996 to 2010, 79 patients were diagnosed with bilateral RB and were eligible for chemotherapy. Chemotherapy was administered prior to and/or following local therapy to the eye. All patients received 3 cycles of chemo-reduction with carboplatin and vincristine, additional cycles of the same or other chemotherapy, local therapy, EBRT and enucleation were determined according to re-evaluation by the ophthalmologist.

RESULTS

Advanced disease was seen in 115 (79%) eyes (group IV and V: 96, Group D and E: 19) out of 146 affected eyes. Tumor response after chemotherapy was observed in 78 patients (98.7%); complete response in 25 (32.1%), partial response in 49 (62.8%) Four (5.1%) had progressive disease. A total of 50 (63.3%) patients required EBRT; 38 for persistent disease, 4 for progressive disease, 2 for new lesions, 2 for re-activation and 4 for disease control. Enucleation was required in 15 (19%). Secondary malignancies occurred in two patients who underwent EBRT; one osteogenic sarcoma and one rhabdomyosarcoma then later osteogenic sarcoma. The 10 year overall survival was 96.3% with a median follow-up time of 3.124 ± 0.536 years (95%CI: 2.074-4.174).

CONCLUSIONS

The 2-drug chemotherapy regimen combined with local therapy appears to be adequate therapy for low stage disease but not in patients with advanced disease. The occurrence of secondary cancers in this group of patients is worrisome further highlighting the deleterious effects of EBRT.

Diagnostic image quality of gadolinium-enhanced T1-weighted MRI with and without fat saturation in children with retinoblastoma

BACKGROUND

Gadolinium-enhanced T1-weighted MRI without fat saturation has been recommended for assessment of retinoblastoma.

OBJECTIVE

The purpose of this study was to compare diagnostic image quality without and with fat saturation following gadolinium administration.

MATERIALS AND METHODS

High-resolution gadolinium-enhanced T1-weighted sequences with and without fat saturation performed in children with subsequently histopathologically confirmed retinoblastoma were included. Image analysis (image quality [1 = poor, 2 = moderate, 3 = good], anatomical detail depiction, tumour extension) was performed by two neuroradiologists in consensus. Enhancement was scored and measured. Signal- and contrast-to-noise ratios were calculated. Image-assessed tumour invasiveness was compared to histopathological findings. Paired sample t-test was used for statistical analysis.

RESULTS

Thirty-six children (mean age, 19.0 ± 16.8 [SD] months) were included. Image quality and anatomical detail depiction were significantly better without fat saturation (P < 0.001). Tumour enhancement was rated higher with fat saturation (P < 0.001). Fat saturation improved detection of (post-)laminar optic nerve infiltration. Detection of choroidal invasion was improved without fat saturation. Combining both sequences was best in the assessment of tumour extension (sensitivity/specificity for (post-)laminar optic nerve infiltration, 75.0%/100.0%, and for choroidal invasion, 87.5%/85.7%).

CONCLUSION

Combined T1-weighted spin-echo imaging with and without fat saturation improved the image quality for assessment of invasiveness of retinoblastoma.

Children's Oncology Group's 2013 blueprint for research: rare tumors

In the US, approximately 2,000 children are diagnosed with rare cancers each year, with 5-year survival ranging from <20% for children with advanced carcinomas to >95% for children with intraocular retinoblastoma or localized germ cell tumors. During the last years, 12 clinical studies have been successfully completed in children with retinoblastoma, liver tumors, germ cell tumors, and infrequent malignancies, including therapeutic, epidemiologic, and biologic studies. Current efforts are centered in the development of large international collaborations to consolidate evidence-based definitions and risk stratifications that will support international Phase 3 clinical trials in germ cell tumors, hepatoblastoma, and other rare cancers.

Aberrant nuclear repressor coreceptor 1 localization in human retinoblastoma

BACKGROUND/AIMS

Nuclear receptor corepressor 1 (NCoR1) is a protein complex with diverse functions in development and tumorigenesis. We investigated the pattern of expression and histopathological correlation of NCoR1 in 41 retinoblastoma tumor samples, 1 retinoblastoma cell line (WERI-Rb-1) and human retinal progenitor cells (hRPCs).

METHODS

Tissue sections from 41 retinoblastoma cases, the retinoblastoma cell line WERI-Rb-1 and hRPCs were stained with rabbit polyclonal anti-NCoR1 H76 antibody. Percentage and intensity of staining were classified by an ocular pathologist from 0 to 3. The paired t test was used to test for differences.

RESULTS

In the nonneoplastic retina, NCoR1 was expressed mainly in cell nuclei. The retinoblastoma tumor cells similarly had nuclear NCoR1 but also had a higher level of cytoplasmic NCoR1 expression compared to all 3 normal retinal cell layers (p < 0.002). In contrast to the normal retina, NCoR1 was mainly expressed in the cytoplasm of the proliferating WERI-Rb-1 cells. This cytoplasmic expression pattern was also seen in the undifferentiated hRPCs.

CONCLUSIONS

The aberrant cytoplasmic expression of NCoR1 in retinoblastoma appears to be associated with the proliferative and/or dedifferentiated properties of retinoblastoma. Further investigation into the role of NCoR1 in retinoblastoma may provide insight into how therapeutically inhibiting its nucleocytoplasmic shuttling may affect retinoblastoma tumor biology.

Real-time ophthalmoscopic findings of superselective intraophthalmic artery chemotherapy in a nonhuman primate model

OBJECTIVE

To report real-time ophthalmoscopic findings during superselective intraophthalmic artery chemotherapy (SSIOAC) in a nonhuman primate model.

METHODS

Six adult male Rhesus macaques (Macacca mulatta) were randomly assigned to 1 of 2 treatment cohorts: melphalan (5 mg/30 mL) or carboplatin (30 mg/30 mL). Each animal underwent 3 separate SSIOAC procedures at 3-week intervals. Digital retinal images were obtained during each infusion. Intravenous fluorescein angiography was performed immediately after each procedure.

RESULTS

All SSIOAC procedures were successfully completed. Toxicities were equally distributed between drug cohorts. Systemic toxicities included mild bone marrow suppression in all animals and anorexia in 1. One animal had greater than 50% narrowing of the treated ophthalmic artery after its second infusion. All 18 procedures (100%) resulted in pulsatile optic nerve and choroid blanching, retinal artery narrowing, and retinal edema. Of the 18 procedures, retinal artery sheathing was found during 17 (94%), and retinal artery precipitates were seen in 10 (56%); choroidal hypoperfusion was seen by fluorescein angiogram in 18 (100%).

CONCLUSION

Real-time ophthalmic investigations are useful and, in our nonhuman primate model, indicate prevalent, acute ocular vascular toxicities during SSIOAC.

CLINICAL RELEVANCE

Real-time retinal imaging is feasible in a nonhuman primate model of SSIOAC. Application to SSIOAC in children may shed insight into reported vascular toxicities.

Frequent prosthesis refitting to prevent implant exposure in patients with retinoblastoma

PURPOSE

To examine the effects of prosthesis refitting on porous orbital implant exposure in 100 patients who underwent enucleation for retinoblastoma.

METHODS

Parameters analyzed included patient's age at enucleation, gender, implant type, frequency of prosthesis adjustment, and use of chemotherapy or radiation. The main outcome measures consisted of the condition of the fornices, condition of the implant (including conjunctival thinning), and condition and functioning ability of the prosthesis.

RESULTS

Increased frequency of visits with the ocularist and number of prosthesis adjustments and refits significantly improved the condition of the implant, fornices, and prosthesis. The patient's age at enucleation, gender, and use of chemotherapy or radiation did not have a significant effect on any of the outcome variables. The condition of the implant was significantly better for porous polyethylene than hydroxyapatite implants (P = .024). No implant exposures were observed.

CONCLUSION

Frequent adjustments and refits by the ocularist are significantly associated with a reduced rate of conjunctival thinning and complete avoidance of implant exposure in patients undergoing enucleation for retinoblastoma. These findings are particularly significant for this population, which historically has demonstrated a high rate of implant exposure.

Functional neuroimaging to characterize visual system development in children with retinoblastoma

PURPOSE

To use functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to investigate visual system development in children being treated for retinoblastoma.

METHODS

Informed consent was obtained for all participants (N = 42) in this institutional review board-approved study. Participants were imaged with a 1.5-T scanner while under propofol sedation. Diagnostic brain and orbital imaging was followed by investigational functional neuroimaging, which included fMRI during photic stimulation through closed eyelids, to measure functional activation in the visual cortex, and DTI, to evaluate diffusion parameters of white matter tracts in the corpus callosum and the periventricular optic radiations. Analysis included 115 examinations of 39 patients with a median age of 16.4 months and age range from 1.5 to 101.5 months at first evaluation.

RESULTS

The blood oxygen level-dependent signal was predominantly negative and located in the anterior visual cortex. Activation was affected by tumor lateralization (unilateral or bilateral), macular involvement, and retinal detachment. Patients who had undergone unilateral enucleation showed cortical dominance corresponding to the projection from the nasal hemiretina in the unaffected eye. Diffusion parameters followed a normal developmental trajectory in the optic radiations and corpus callosum, but variability was greater in the splenium than in the genu of the corpus callosum.

CONCLUSIONS

Longitudinal functional neuroimaging demonstrated important effects of disease and treatment. Therefore, fMRI and DTI may be useful for characterizing the impact of retinoblastoma on the developing visual system and improving the prediction of visual outcome in survivors.

Comparison of two methods for carboplatin dosing in children with retinoblastoma

BACKGROUND

Carboplatin is the most effective drug in retinoblastoma but systemic clearance is variable in young patients. While most regimens use a flat dose, individualized targeting may provide a more adjusted systemic exposure.

PATIENTS AND METHODS

We compared carboplatin doses between two groups of children with retinoblastoma that were treated using a flat dose of 560 mg/m(2) or a targeted AUC of 6.5 using a modified Calvert formula.

RESULTS

Ninety-eight patients with retinoblastoma received a total of 576 cycles of carboplatin (median 8 cycles). Fifty patients (51%) received a fixed dose per m(2), 32 (33%) received a dose based on AUC, 1 patient received fixed dose per kilogram, and in 15 patients a combination AUC and fixed doses was used. The median cumulative carboplatin dose (mg/m(2)) for patients who received eight cycles using fixed per m(2) dosing was 2151.8 (range, 1414.2-2852.0), compared to 1104.1 for nine patients who received eight cycles using Calvert dosing (range, 779.0-1992.7) (P < 0.001). For cycles given using AUC, the median percentage of the hypothetical fixed per m(2) dose was 70% (range, 48-134%). Younger patients had larger differences. Patients receiving carboplatin based on fixed per m(2) dosing were 3.0 times more likely to have a platelet transfusion (95% confidence interval, 1.3-7.3).

CONCLUSIONS

Carboplatin administration needs to consider the changes in renal function occurring during the first months of life. The use of a targeted AUC provides the most accurate method; however, mg per kg of body weight dosing is a very reliable alternative method.

Required reduction in dose of chemotherapy for retinoblastoma due to down syndrome-associated chemosensitivity

PURPOSE

To report a case of a boy with bilateral germinal retinoblastoma and Down syndrome who was successfully treated despite a predilection toward chemotoxicity associated with Down syndrome.

METHODS

A 3-month-old boy presenting with germinal retinoblastoma and Down syndrome was treated with diode laser and systemic carboplatin and low-dose vincristine, with gradual dose escalation. Etoposide and cyclosporine were later added for a greater tumor response. After cyclosporine was added, the patient was hospitalized due to vincristine toxicity. The vincristine dose was further lowered, and periocular carboplatin injections were given to establish control of intraocular disease.

RESULTS

The tumors regressed after 11 sessions of laser and chemotherapy. Because of residual vitreous seeding in the right eye, a series of two periocular carboplatin injections were given. Six more laser sessions were applied to the tumors. There is no evidence of active retinoblastoma after 11 months of follow-up.

CONCLUSION

Because of increased chemosensitivity in patients with Down syndrome, it is important to reduce systemic drug dosages and consider augmenting local therapy in retinoblastoma cases.

Lack of correlation between the histologic and magnetic resonance imaging results of optic nerve involvement in eyes primarily enucleated for retinoblastoma

PURPOSE

To correlate the histologic and magnetic resonance imaging results of the optic nerve in eyes primarily enucleated for retinoblastoma.

DESIGN

Retrospective, clinicopathologic correlation.

PARTICIPANTS

Sixty-seven consecutive patients with retinoblastoma who underwent primary enucleation.

METHODS

The histologic results of 67 eyes from 67 patients with retinoblastoma who underwent primary enucleation between March 1997 and January 2008 were studied for evidence of optic nerve invasion. Two neuroradiologists independently reviewed available preoperative magnetic resonance imaging studies with special emphasis on nonenhanced T2-weighted and gadolinium-enhanced T1-weighted imaging for evidence of optic nerve invasion. A weighted kappa statistic was used to assess agreement between observers.

MAIN OUTCOME MEASURES

Correlation between neuroradiologists and histologic results.

RESULTS

Of the 67 eyes studied, 60 had preoperative magnetic resonance images, 58 of which were deemed appropriate for review by both neuroradiologists. Review of the histologic results showed optic nerve involvement in 62 (93%) of 67 eyes: 28 prelaminar (42%), 24 laminar (36%), and 10 postlaminar (15%). On review of the magnetic resonance scans, the first neuroradiologist identified optic nerve involvement in 57 (95%) of 60 eyes: 26 prelaminar (43%), 10 laminar (17%), and 11 postlaminar (18%). The second neuroradiologist identified optic nerve involvement in 46 (77%) of 60 eyes: 33 prelaminar (55%), 9 laminar (15%), and 4 postlaminar (7%). Moderate agreement existed between neuroradiologists (kappa, 0.55). Poor and fair agreement existed between each of the 2 neuroradiologists and histologic results, respectively (kappa, 0.29 and 0.17). Exophytic tumors showed the greatest disparity (kappa, -0.20 and -0.13) between magnetic resonance imaging and histologic results.

CONCLUSIONS

Limited correlation was found between magnetic resonance imaging and histologic results in assessing optic nerve invasion in eyes with retinoblastoma. Magnetic resonance imaging using routine imaging technologies, although useful in the evaluation of retinoblastoma, has limited usefulness in assessing the exact extent of optic nerve invasion; high-risk features of retinoblastoma such as postlaminar invasion remain best defined by histologic analysis. This study demonstrates that the interpretation of optic nerve involvement by a radiologist should not be the determining factor to defer enucleation in favor of neoadjuvant therapy.

Predictive factors of invasion in eyes with retinoblastoma enucleated after eye salvage treatments

BACKGROUND

The impact of chemotherapy, focal therapies, radiation and co-existing ocular morbidities on histology of eyes with retinoblastoma enucleated following chemoreduction is not well known.

PROCEDURE

Twenty-five eyes (23 patients) with retinoblastoma enucleated after failing eye-salvage therapy were evaluated. Reasons for enucleation (tumor progression, subretinal or vitreous seeds) and co-morbid conditions (neovascular glaucoma, cataract, vitreous hemorrhage and retinal detachment) were documented. All specimens were reviewed for evidence of ciliary body, choroidal, optic nerve, and scleral invasion.

RESULTS

The median age at diagnosis was 14 months (range, 1-37 months). Twenty eyes were classified as Reese-Ellsworth Group IV-V at diagnosis. Twenty-four eyes had recurrent disease at enucleation; one eye was enucleated for neovascular glaucoma and vitreous hemorrhage. Co-existing ocular morbidities at enucleation included vitreous hemorrhage (n = 6), retinal detachment (n = 9), neovascular glaucoma (n = 9) and cataracts (n = 3). Histologic findings included choroidal invasion (n = 7), ciliary body invasion (n = 4), optic nerve invasion (n = 6) and scleral invasion (n = 3). The median time from diagnosis to enucleation was 11 months. Co-existing retinal detachment and vitreous hemorrhage significantly increased the likelihood of optic nerve invasion (P = 0.014 and P = 0.011, respectively). Prolonged time to enucleation was significantly associated with the likelihood of choroidal (P = 0.010) and ciliary body (P = 0.021) invasion as well as invasion of multiple sites.

CONCLUSION

In eyes with retinoblastoma enucleated after chemoreduction, co-existing ocular morbidities and time to enucleation are predictive of extra-retinal extension.