Impact of RB1 gene mutation type in retinoblastoma patients on clinical presentation and management outcome

Characterization of a novel variant in KCNJ16, encoding Kir5.1 channel

The essential role of the inwardly rectifying potassium channel Kir5.1 (KCNJ16) in controlling electrolyte homeostasis and blood pressure has been demonstrated in human and animal studies. Previous studies have identified several bi-allelic mutations of KCNJ16 in humans, causing severe hypokalemia, renal salt wasting, and disturbed acid-base homeostasis. Here, we identified a novel homozygous variant of KCNJ16, I26T, in an Amish patient affected with polydipsia, developmental delay, and chronic metabolic acidosis with low serum bicarbonate concentration. Subsequently, we generated the rat model with I26T mutation using Dahl salt-sensitive rat (I26T rat) to characterize this variant. The male mutant rats displayed similar blood pressure and electrolyte homeostasis under baseline and with a high salt (4% NaCl) challenge. Blood pH, HCO3 - and renal damage also remained similar between WT and I26T rats after high salt challenge. Additionally, single-channel patch clamp analysis revealed similar channel activity in CHO cells overexpressed with WT and I26T mutant Kir4.1/5.1 channels. In summary, this study reported a novel variant in KCNJ16, namely I26T, which is likely a benign variant and not associated with pathologic phenotype in either human or Dahl salt-sensitive rats, indicating that the type/location of variant should be considered when diagnosing and treating patients with KCNJ16 mutations.

Mutational analysis of the RB1 gene in patients with unilateral retinoblastoma

Purpose

Retinoblastoma, a childhood cancer originating in the retina, is primarily attributed to pathogenic RB1 mutations The aim of this study is to conduct a mutational analysis of the RB1 gene in cases of unilateral Retinoblastoma among individuals within the Jordanian population.

Methods

In this study, the peripheral blood of 50 unilateral Rb patients was collected, genomic DNA was extracted, and mutations were identified using Next Generation Sequencing (NGS) analysis.

Results

In this cohort of 50 unrelated patients with unilateral Rb, the median age at diagnosis was eight months (mean, 12 months; range; 2 weeks to 54 months). Twenty-eight (56%) were males, 29 (58%) had the disease in the right eye, 3 (6%) had a positive family history of Rb, and 20 (40%) were diagnosed within the first year of life. RB1 gene pathogenic mutations were detected in 14 out of 50 (28%) patients, indicating germline disease. Among unilateral non-familial cases, 11 out of 47 (23%) were found to have germline RB1 mutations. Overall, five (36%) of the germline cases had the same mutation detected in one of the parents consistent with an inherited disease (four (80%) were of paternal origin); 3 (60%) of these had affected carrier parent, two (40%) had an unaffected carrier parent. Nine (64%) patients had the nonsense mutation, and six (43%) had the mosaic mutation. The significant prognostic factors for positive genetic testing were positive family history (p = 0.018) and age at diagnosis less than 12 months (p = 0.03). At a median of 54 months follow-up, two (4%) patients were dead from distant metastasis. The overall eye salvage rate was 44% (n = 22/50) eyes; 100% for groups A, B, and C, 60% for group D, and none for group E eyes. There was no correlation between the presence of germline mutation and outcome in terms of eye salvage, metastasis, and survival.

Conclusion

In this study, 28% of patients with unilateral Rb had germline RB1 mutations, of which 43% were inherited, and one-third presented beyond their first year of life. Therefore, molecular screening is critical for genetic counseling regarding the risk for inherited Rb in unilateral cases, including those with no family history, regardless of the age at diagnosis. However, germline mutations did not appear to significantly predict patient outcomes regarding eye salvage, metastasis, and survival.

Familial retinoblastoma: variations in clinical presentation and management based on paternal versus maternal inheritance

BACKGROUND

Several studies have demonstrated the effect of parent-of-origin on retinoblastoma penetrance. The purpose of the current study was to assess differences in clinical presentation of paternally versus maternally inherited retinoblastoma.

METHODS

The clinical records of all children with familial retinoblastoma treated on a tertiary Ocular Oncology Service between December 1975 and May 2020 were reviewed retrospectively.

RESULTS

A total of 179 patients with familial retinoblastoma were included. Paternal inheritance (PI) was identified in 109 (61%) patients and maternal inheritance (MI) in 70 patients (39%). A comparison (PI vs MI) revealed PI patients were older at presentation (57.2 vs 24.4 months [P = 0.002]) with no difference in patient sex (53% females vs 57% males [P = 0.606]) or number of family members affected (3.2 vs 3.0 family members [P = 0.255]). PI patients had more advanced classification according to the International Classification of Retinoblastoma (ICRB) (group E: 31% vs 8% [P = 0.012)] and greater largest tumor in basal diameter (9.0 vs 6.2 mm [P = 0.040]) and thickness (5.6 vs 4.0 mm [P = 0.038]); they were also less likely to be located in the macula (40% vs 60% [P = 0.004]). There was no difference in tumor laterality (69% vs 64% bilaterality [P = 0.530]). PI patients required enucleation more frequently (34% vs 14% [P = 0.007]). There was no difference in need for plaque radiotherapy (P = 0.86) or chemotherapy (P = 0.85). One PI patient developed metastatic retinoblastoma, and there were no retinoblastoma-related deaths.

CONCLUSIONS

Patients with paternally inherited retinoblastoma presented at an older age, with larger, more peripheral tumors and more advanced ICRB group, and were more likely to require enucleation compared to those with maternally inherited retinoblastoma.

Advancements in Retinoblastoma Treatment: Unraveling the Potential of Intravitreal Chemotherapy

Retinoblastoma necessitates urgent attention due to its potential fatality if untreated. Multiple treatment options are available and should be employed according to size, location, and the extent of dissemination. This review emphasizes the need for increased awareness, advanced diagnostic tools, and innovative treatment approaches, especially intravitreal chemotherapy (IVitC) to address the diverse manifestations and aggressive nature of retinoblastoma. Timely diagnosis and commitment to treatment are pivotal, as delays and reluctance to undergo enucleation contribute to unfavorable outcomes. The evolving treatment landscape, spanning from traditional interventions to modern targeted therapies such as intravitreal melphalan, holds promise for improved outcomes. While the intravitreal approach presents challenges, ongoing research aims to establish its definitive role in retinoblastoma treatment. In the treatment of retinoblastoma, IVitC raises considerations about side effects. The risk of tumor spread beyond the eye is rare, emphasising the potential of IVitC in carefully selected cases. Intravitreal injections exhibit fewer local adverse effects compared to intra-arterial chemotherapy, with careful measures reducing significant ocular complications. The evaluation of ocular toxicity, particularly with melphalan, underscores the importance of a nuanced approach to achieve the right balance between therapeutic efficacy and ocular safety. This comprehensive analysis of studies on IVitC and its ocular and systemic complications provides valuable insights for enhanced patient care. The review concludes with a focus on balancing safety and efficacy in local chemotherapeutic drugs, highlighting the need for thoughtful measures and continued research to optimise treatment modalities globally.

Causes of death and survival analysis for patients with retinoblastoma in Jordan

Purpose

To analyze causes and prognostic factors for death among Retinoblastoma (Rb) patients treated at a single specialized tertiary cancer center in Jordan.

Methods

We reviewed the mortality causes for all Rb patients who have been treated at the King Hussein Cancer Center between 2003 and 2019 and were followed for at least 3 years after diagnosis. The main outcome measures included demographics, laterality, tumor stage, treatment modalities, metastasis, survival, and causes of death.

Results

Twenty-four (5%) of the 478 patients died from retinoblastoma and 5-year survival was 94%. The mean age at diagnosis was 15 months (median, 18 months; range, 4-38 months); eight (33%) received diagnoses within the first year of life. Eleven (46%) were boys, 16 (67%) had bilateral disease, and 3 (13%) had a positive family history. The stage for the worst eye was C for 1 (4%) patient, D in 6 (25%) patients, and E (T3) in 15 (63%) patients. Two patients had extraocular Rb at diagnosis, and four of the patients who had intraocular Rb at diagnosis refused treatment and then came back with extraocular Rb. In total, extraocular disease was encountered in six eyes (six patients). After a 120-month median follow-up period, 24 patients (5%) died of second neoplasms (n = 3) or metastases (n = 21). Significant predictive factors for metastasis and death included advanced IIRC tumor stage (p < 0.0001), the presence of high-risk pathological features in the enucleated eyes (p = 0.013), parental refusal of the recommended primary treatment plan (p < 0.0001), and extraocular extension (p < 0.0001).

Conclusion

The 5-year survival rates of Rb patients in Jordan are as high as those in high-income countries. However, 5% are still dying from metastatic disease, prompting the need for awareness campaigns to educate the public about the high cure rates and to prevent treatment abandonment.

Retinoblastoma and uveal melanoma in Jordan: incidence, demographics, and survival (2011-2020)

PURPOSE

We present an epidemiologic analysis of retinoblastoma (RB) and uveal melanoma (UM) in Jordan to aid national strategies for improved ocular cancer surveillance and control.

METHODS

A retrospective cohort of all Jordanian patients with RB and UM diagnosed over 10 years (2011-2020). Outcome measures included incidence, demographics, and outcomes.

RESULTS

Retinoblastoma (n = 124) was more common than UM (n = 82); there was no sex predilection for either group. The median age at diagnosis of RB was 15 months(Six and 28 months for bilateral and unilateral cases, respectively), and the mean age-adjusted incidence was 8.2 cases per-million-children per year for children aged five years or less(one per 15,620 newborn per year). Fifty-one(41%) had bilateral disease, and 18(15%) had familial disease. Ninety-six(55%) eyes were group D or E(78% were T3/T4), and the five-year survival rate was 96%.For UM, the median age at diagnosis was 45 years with an incidence of 1.39 new cases per year per one million population. All(100%) had nonfamilial unilateral disease. Seventy-three(89%) had the tumor in the choroid, and 48(58%) had an advanced tumor that had invaded the sclera or the orbit (T3/T4) tumor. Sixty-two(76%) were treated by I-125 radioactive plaque, with globe salvage in 59(95%); the five-year survival rate was 85%.

CONCLUSION

In Jordan, RB is more common and has better survival than UM. RB in Jordan and Western countries is equal in terms of incidence, globe salvage, and survival. UM is less common, with lower age at diagnosis (that was associated with better survival) in Jordan than in Western countries.

Germline RB1 Mutation in Retinoblastoma Patients: Detection Methods and Implication in Tumor Focality

Purpose

The study aimed to generate a stepwise method to reduce the workload of full-scale RB1 sequencing for germline mutation screening in retinoblastoma (RB) patients. The implication of germline mutation in tumor focality was also determined in this study.

Methods

A stepwise method was created on the basis of "hotspot" exons analyzed using data on germline RB1 mutation in the RB1-Leiden Open Variation Database and then tested for mutation screening in the blood DNA of 42 patients with RB. The method was compared with the clinical next-generation sequencing (NGS) panel in terms of sequencing outcomes. The germline RB1 mutation was examined in association with multifocality in RB.

Results

Germline RB1 mutation was identified in 61% of all bilateral cases in the first step of the 3 stepwise method and in 78% and 89% for the two and three steps combined, respectively. NGS detected a mosaic variant of RB1 that was not detected by the first two steps and increased the sensitivity from 78% to 83%. Analysis of the relationship between mutation status and tumor focality indicated that multifocality in RB was dependent on germline RB1 mutation, confirming a higher tendency to have a germline RB1 mutation in patients with multifocal RB.

Conclusions

A 3 stepwise method reduces the workload needed for sequencing of the RB1 for bilateral cases. NGS outweighs conventional sequencing in terms of the identification of germline mosaic variants. Multifocal tumors in RB may be used to presume germline mutation.

Translational Relevance

The presence of "hotspot" exons of germline RB1 mutation in bilateral cases facilitates a mutation screening. However, when genetic testing is not available, multifocality in RB regardless of tumor laterality is predictive of germline RB1 mutation.

Novel insights into RB1 mutation

Since the discovery of the retinoblastoma susceptibility gene (RB1) decades ago, RB1 has been regarded as a prototype tumor suppressor gene providing a paradigm for tumor genetic research. Constant research has updated the understanding of RB1-related pathways and their impact on tumor and nontumor diseases. Mutation of RB1 gene has been observed in multiple types of malignant tumors including prostate cancer, lung cancer, breast cancer, and almost every familial and sporadic case of retinoblastoma. Even if well-known and long-investigated, the application potential of RB1 mutation has not been fully tapped. In this review, we focus on the mechanism underlying RB1 mutation during oncogenesis. Therapeutically, we have further discussed potential clinical strategies by targeting RB1-mutated cancers. The unsolved problems and prospects of RB1 mutation are also discussed.

Cyclophosphamide inhibits Pax5 methylation to regulate the growth of retinoblastoma via the Notch1 pathway

Retinoblastoma (Rb) is the most common intraocular malignant tumor in infants. Here, we investigated the function and mechanism of cyclophosphamide (CTX) in the development of Rb. Real-time quantitative polymerase chain reaction (RT-qPCR) results showed that paired box protein 5 (Pax5) expression was down-regulated in Rb tissues and cell lines. Methylation-specific PCR (MSP) results showed that the methylation level of Pax5 was up-regulated in Rb. After treatment with CTX, the Pax5 expression in Rb cell lines was increased significantly. The methylation of Pax5 and the expression of DNA methyltransferases (DNMTs) were down-regulated in the CTX group. Cyclophosphamide inhibited cell proliferation, migration, and invasion, promoted cell apoptosis via the Notch1 pathway. DNA methyltransferase inhibitor SGI-1027 had synergistic effects with CTX. Paired box protein 5 siRNA was transfected into Y79 cells treated with CTX. The expression of DNMTs, Pax5, the Notch1 pathway and apoptosis marker protein was detected by Western blotting, and changes in cell behavior were detected, respectively. Results showed that knockdown of Pax5 reversed the effects of CTX. Moreover, the Notch1 activator Valproic acid (VPA) abolished the inhibitory effects of CTX on Rb development. Moreover, CTX inhibited tumor growth in nude mice. These findings demonstrated that CTX up-regulated Pax5 expression by down-regulating DNMTs expression, and then inhibited the Notch1 signaling pathway activation and Rb growth.

Identification of novel RB1 genetic variants in Retinoblastoma patients and their impact on clinical outcome

BACKGROUND

Retinoblastoma (RB) is an intraocular childhood cancer develops due to inactivation of RB1 gene. Identification of RB1 genetic variants, correlating and confirming genetic test results with clinical outcomes are crucial for effective RB management.

METHODS

Retrospective study of 62 RB patients and 14 family members who underwent genetic testing either by next generation sequencing (NGS) or multiplex ligation-dependent probe amplification (MLPA) or by both for screening RB1 germline mutations present in peripheral blood. Mutational outcomes were correlated with clinical outcomes evaluated over a follow-up period of 12 months.

RESULTS

Of the 62 patients, 35 (56%) had bilateral RB and 27 (44%) had unilateral RB. Out of 24 (52%) variants detected by NGS, 9 (37.5%) were novel and 15 (62.5%) were known in 46 probands. Six (18%) gross deletions were detected by MLPA in 34 probands. The mutation detection rate by NGS and MLPA in unilateral cases was 15% (n = 4) and 74% (n = 26) in bilateral cases. In patients with RB1 genetic mutations versus those without, the rate of primary enucleation (7 (12%) vs 18 (44%) eyes; p = .0008) was inversely proportional to tumor recurrence (25 (45%) vs 6 (15%) eyes; p = .002). There was no difference in the rate of globe salvage and metastasis, over a mean follow-up period of 12 months.

CONCLUSION

The mutations screening is important for risk assessment in future siblings and offspring of RB patients and most important in unilateral RB for determining if hereditary or not hereditary RB. Its role in predicting clinical outcomes is yet to be determined.

Clinical evaluation of RB1 genetic testing reveals novel mutations in Vietnamese patients with retinoblastoma

Clinical evaluation of the genetic testing strategy is essential for ensuring the correct determination of mutation carriers. The current study retrospectively analyzed genetic and clinicopathological data from 62 Vietnamese patients with retinoblastoma (RB) referred to the Vinmec Hi-Tech Center for RB transcriptional corepressor 1 (RB1) genetic testing between 2017 and 2019. The present study aimed to evaluate the sensitivity of the Next Generation Sequencing (NGS) method to identify novel RB1 mutations, and to consider using age at diagnosis as a risk factor. Genomic DNA was analyzed with custom panel based targeted NGS. NGS was performed on the Beijing Genomics Institute (BGI) sequencing platform, and pathogenic or likely pathogenic variants were confirmed by Sanger sequencing, quantitative PCR (qPCR) or Multiplex Ligation-dependent Probe Amplification assay (MLPA). Constitutional RB1 variants were identified in 100% (25/25) of the bilateral cases, while several common previously reported RB1 mutations were also recorded. In addition, in Vietnamese patients with RB, nine novel RB1 mutations were identified. Children aged between 0-36 months were more likely to be RB1 carriers compared with those aged >36 months. The current findings indicated that the NGS method implemented in the Vinmec Hi-Tech Center was highly accurate, and age at diagnosis may be used to assess the risk of hereditary RB. Furthermore, the newly identified RB1 mutations may provide additional data to improve the current understanding of the mechanisms underlying RB1 inactivation and the development of rapid assays for detecting RB1 mutations. Overall, the present study suggested that NGS may be applied for detecting germline RB1 mutations in routine clinical practice.

Multi-Functionalized Nanomaterials and Nanoparticles for Diagnosis and Treatment of Retinoblastoma

Retinoblastoma is a rare type of cancer, and its treatment, as well as diagnosis, is challenging, owing to mutations in the tumor-suppressor genes and lack of targeted, efficient, cost-effective therapy, exhibiting a significant need for novel approaches to address these concerns. For this purpose, nanotechnology has revolutionized the field of medicine with versatile potential capabilities for both the diagnosis, as well as the treatment, of retinoblastoma via the targeted and controlled delivery of anticancer drugs via binding to the overexpressed retinoblastoma gene. Nanotechnology has also generated massive advancements in the treatment of retinoblastoma based on the use of surface-tailored multi-functionalized nanocarriers; overexpressed receptor-based nanocarriers ligands (folate, galactose, and hyaluronic acid); lipid-based nanocarriers; and metallic nanocarriers. These nanocarriers seem to benchmark in mitigating a plethora of malignant retinoblastoma via targeted delivery at a specified site, resulting in programmed apoptosis in cancer cells. The effectiveness of these nanoplatforms in diagnosing and treating intraocular cancers such as retinoblastoma has not been properly discussed, despite the increasing significance of nanomedicine in cancer management. This article reviewed the recent milestones and future development areas in the field of intraocular drug delivery and diagnostic platforms focused on nanotechnology.

Roles of the microRNA‑338‑3p/NOVA1 axis in retinoblastoma

Retinoblastoma (RB) is an intraocular malignancy that mainly affects young children. Previous reports have demonstrated that mutations or the inactivation of the RB1 gene were the main cause of RB; however, disruption of the intracellular signaling pathways following deficiency of RB1 requires further investigation. Based on the Gene Expression Omnibus data and bioinformatics prediction, the present study aimed to investigate the microRNA (miR)-338-3p/neuro-oncological ventral antigen 1 (NOVA1) axis in RB. Subsequently, overexpression and knockdown of miR-338-3p and NOVA1, respectively, were performed to study the role of miR-338-3p/NOVA1 in the progression of the RB cells. The results demonstrated that overexpression of miR-338-3p significantly inhibited cell proliferation, migration and invasion, and promoted apoptosis of the RB cells. Moreover, knockdown of NOVA1 showed similar results. A dual-luciferase reporter assay and rescue experiments further confirmed the direct binding between miR-338-3p and NOVA1. Taken together, the results indicated that miR-338-3p acted as tumor suppressor by targeting the oncogene of NOVA1 in RB, which may serve as potential therapeutic targets in RB.

Identification of driver genes with aberrantly alternative splicing events in pediatric patients with retinoblastoma

Retinoblastoma (RB) is one of the most common cancer in children. However, the specific mechanism about RB tumorigenesis has not been fully understood. In this study, to comprehensively characterize the splicing alterations in the tumorigenesis of RB, we analyzed the differential alternative splicing events in RB. Specifically, the isoforms of RB1 were downregulated in the RB samples, and a large proportion of differentially expressed genes had multiple differentially expressed transcripts (64%). We identified 1453 genes with differential alternative splicing, among which, SE accounted for the majority, followed by MXE, RI, A3SS, and A5SS. Furthermore, the biological function related to the normal function of eyes, and E2F family TFs were significantly enriched by the genes with differential alternative splicing. Among the genes associated with visual sense, ABCA4 was found to have two mutually exclusive exons, resulting in two isoforms with different functionalities. Notably, DAZAP1 was identified as one of the critical splicing factors in RB, which was potentially involved in E2F and RB pathways. Functionally, differential binding sites in DAZAP1 protein were significantly observed between RB and normal samples. Based on the comprehensive analysis of the differential alternative splicing events and splicing factors, we identified some driver genes with differential alternative splicing and critical splicing factors involved in RB, which would greatly improve our understanding of the alternative splicing process in the tumorigenesis of RB.

LncRNA NEAT1 Knockdown Inhibits Retinoblastoma Progression by miR-3619-5p/LASP1 Axis

Retinoblastoma (RB) is the most common intraocular tumor in childhood. Long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NTAT1) has been reported to be related to RB progression. This study aims to study the molecular mechanism of NEAT1 in regulating cell cycle, proliferation, apoptosis, migration, and invasion in RB. The expression levels of NEAT1 and miR-3619-5p were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression of LIM and SH3 domain protein 1 (LASP1) was measured by western blot. The proliferation of RB cells was analyzed by cell counting kit-8 (CCK-8) and cell colony formation assays. Cell migration and invasion were evaluated by transwell assay. Cell cycle and apoptosis were assessed by flow cytometry analysis. The association between miR-3619-5p and NEAT1 or LASP1 was predicted by starBase 3.0 database and identified by dual-luciferase reporter assay. The effects of NEAT1 knockdown on the tumor growth in vivo were detected by in vivo tumor formation assay. NEAT1 expression was dramatically up-regulated, and miR-3619-5p expression was obviously downregulated in RB tissues and cells compared with control groups. The protein level of LASP1 was obviously increased in RB tissues or cells relative to paracancerous normal tissues or cells, respectively. Functionally, NEAT1 silencing inhibited RB cell migration, invasion, and proliferation, whereas induced cell apoptosis and cell cycle arrest in RB; this phenomenon was partially abolished by miR-3619-5p inhibitor. Mechanistically, NEAT1 acted as a sponge of miR-3619-5p, and miR-3619-5p was associated with LASP1. In addition, NEAT1 knockdown decreased the volume and weight of RB tumor in vivo. Together, NEAT1 silencing repressed cell migration, invasion, and proliferation, whereas induced cell apoptosis and cycle arrest by sponging miR-3619-5p to inhibit LASP1 expression in RB cells. This study may provide a theoretical basis for RB therapy.

Simultaneous identification of clinically relevant RB1 mutations and copy number alterations in aqueous humor of retinoblastoma eyes

BACKGROUND

Detection of germline RB1 mutations is critical for risk assessment of retinoblastoma (RB) patients. Assessment of somatic copy number alterations (SCNAs) is also critically important because of their prognostic significance. Herein we present a refined approach for the simultaneous identification of RB1 variants and SCNAs in the aqueous humor (AH) of RB eyes.

MATERIALS AND METHODS

Subjects included 7 eyes of 6 RB patients that underwent AH extraction, and 4 matched tumor samples. Cell-free DNA (cfDNA) was isolated and sequenced to assess genome-wide SCNAs. The same sequencing libraries then underwent targeted resequencing and mutation detection using a custom hybridization panel that targets RB1 and MYCN. Illumina paired-end 2x150bp sequencing was used to characterize single-nucleotide variants (SNVs) and loss of heterozygosity (LOH). Results were compared to peripheral blood RB1 testing. Tumor fraction (TFx) was calculated using ichorCNA.

RESULTS

Four of 7 AH samples contained clinically significant SCNAs. Of the 3 other samples, 1 showed focal MYCN amplification and 1 showed focal RB1 deletion. All 4 enucleated tumors contained SCNAs. Mutational analysis of tumor DNA identified all first hits (2 germline RB1 SNVs, 2 germline CNAs) and second hits (4 RB1 SNVs). RB1 variants in AH were concordant with those obtained from corresponding tumor tissue and blood. In AH samples without paired tumor, both RB1 hits were identified with high variant allele frequency, even in the absence of SCNAs.

CONCLUSIONS

AH liquid biopsy is a minimally invasive, in vivo alternative to tissue analysis for the simultaneous identification of RB1 variants and SCNAs in RB eyes.

Programmed screening for retinoblastoma enhances early diagnosis and improves management outcome for high-risk children

PURPOSE

To study the impact of a Retinoblastoma (Rb) screening program in the absence of genetic testing on the management and outcome of high-risk children.

METHODS

This is a retrospective, clinical case series of 76 children from families involved in a Rb screening program as they had higher than normal risk as calculated by the conventional ways without genetic testing. Data included calculated risk, method of diagnosis, demographics, tumor features, treatment modalities, and management outcome.

RESULTS

Out of the 76 children screened, 46 children were diagnosed with Rb (12 by screening and 34 had signs of Rb), the other 30 were free of disease. Patients diagnosed by screening were younger (mean; 2.4 months vs 15.8 months for the group with signs of Rb), had significantly earlier tumor stage at diagnosis (p = .0001), higher eye salvage rate (p = .0001), less need for systemic chemotherapy (p = .022), and better visual outcome (p = .0017) than the other group. None of the eyes were group D or E, enucleated or irradiated. Six (50%) patients were cured without chemotherapy, and the visual acuity was 0.5 or better in 55% of eyes. Of interest, 71% of tumors were diagnosed by the age of 6 months, 90% by the age of 1 year, and no new tumor appeared after the age of 2 years.

CONCLUSION

Even in the absence of genetic testing, screening for children with high risk for Rb is effective in enhancing early diagnosis, improving visual outcome, and increasing eye salvage rate with limited exposure to treatment burden.