Differences in Childhood Growth Parameters Between Patients With Somatic and Heritable Retinoblastoma.

Purpose: Little is known regarding differences in childhood growth between somatic and heritable retinoblastoma (Rb) populations. We aimed to compare childhood growth parameters between somatic and heritable Rb cohorts at birth and at time of diagnosis with Rb. Methods: A multinational, longitudinal cohort study was conducted with patients from 11 centers in 10 countries who presented with treatment naïve Rb from January to December 2019. Variables of interest included age, sex, and size characteristics at birth and at time of presentation, as well as germline mutation status. After Bonferroni correction, results were statistically significant if the P value was less than 0.005. Results: We enrolled 696 patients, with 253 analyzed after exclusion criteria applied. Between somatic (n = 39) and heritable (n = 214) Rb cohorts, with males and females analyzed separately, there was no significant difference in birth weight percentile, weight percentile at time of diagnosis, length percentile at time of diagnosis, weight-for-length percentile at time of diagnosis, or change of weight percentile from birth to time of diagnosis. Patients with heritable Rb had a smaller mean weight percentile at birth and smaller mean weight and length percentiles at time of diagnosis with Rb, although this difference was not statistically significant. All cohorts experienced a slight negative change of weight percentile from birth to time of diagnosis. No cohort mean percentiles met criteria for failure to thrive, defined as less than the 5th percentile. Conclusions: Children with Rb seem to have normal birth and childhood growth patterns. There is no definitive evidence that somatic or heritable Rb has a biological or environmental impact on childhood growth parameters.

The role of maternal age & birth order on the development of unilateral and bilateral retinoblastoma: a multicentre study.

BACKGROUND/OBJECTIVES: Retinoblastoma is a common childhood intraocular malignancy, the bilateral form of which most commonly results from a de novo germline pathogenic variant in the RB1 gene. Both advanced maternal age and decreasing birth order are known to increase the risk of de novo germline pathogenic variants, while the influence of national wealth is understudied. This cohort study aimed to retrospectively observe whether these factors influence the ratio of bilateral retinoblastoma cases compared to unilateral retinoblastoma, thereby inferring an influence on the development of de novo germline pathogenic variants in RB1. SUBJECTS/METHODS: Data from 688 patients from 11 centres in 10 countries were analysed using a series of statistical methods. RESULTS: No associations were found between advanced maternal age, birth order or GDP per capita and the ratio of bilateral to unilateral retinoblastoma cases (p values = 0.534, 0.201, 0.067, respectively), indicating that these factors do not contribute to the development of a de novo pathogenic variant. CONCLUSIONS: Despite a lack of a definitive control group and genetic testing, this study demonstrates that advanced maternal age, birth order or GDP per capita do not influence the risk of developing a bilateral retinoblastoma.

Risk factors associated with abandonment of care in retinoblastoma: analysis of 692 patients from 10 countries.

BACKGROUND: Rates of care abandonment for retinoblastoma (RB) demonstrate significant geographical variation; however, other variables that place a patient at risk of abandoning care remain unclear. This study aims to identify the risk factors for care abandonment across a multinational set of patients. METHODS: A prospective, observational study of 692 patients from 11 RB centres in 10 countries was conducted from 1 January 2019 to 31 December 2019. Multivariate logistic regression was used to identify risk factors associated with higher rates of care abandonment. RESULTS: Logistic regression showed a higher risk of abandoning care based on country (high-risk countries include Bangladesh (OR=18.1), Pakistan (OR=45.5) and Peru (OR=9.23), p<0.001), female sex (OR=2.39, p=0.013) and advanced clinical stage (OR=4.22, p<0.001). Enucleation as primary treatment was not associated with a higher risk of care abandonment (OR=0.59, p=0.206). CONCLUSION: Country, advanced disease and female sex were all associated with higher rates of abandonment. In this analysis, enucleation as the primary treatment was not associated with abandonment. Further research investigating cultural barriers can enable the building of targeted retention strategies unique to each country.

The Effects of Breastfeeding on Retinoblastoma Development: Results from an International Multicenter Retinoblastoma Survey.

The protective effects of breastfeeding on various childhood malignancies have been established but an association has not yet been determined for retinoblastoma (RB). We aimed to further investigate the role of breastfeeding in the severity of nonhereditary RB development, assessing relationship to (1) age at diagnosis, (2) ocular prognosis, measured by International Intraocular RB Classification (IIRC) or Intraocular Classification of RB (ICRB) group and success of eye salvage, and (3) extraocular involvement. Analyses were performed on a global dataset subgroup of 344 RB patients whose legal guardian(s) consented to answer a neonatal questionnaire. Patients with undetermined or mixed feeding history, family history of RB, or sporadic bilateral RB were excluded. There was no statistically significant difference between breastfed and formula-fed groups in (1) age at diagnosis (p = 0.20), (2) ocular prognosis measures of IIRC/ICRB group (p = 0.62) and success of eye salvage (p = 0.16), or (3) extraocular involvement shown by International Retinoblastoma Staging System (IRSS) at presentation (p = 0.74), lymph node involvement (p = 0.20), and distant metastases (p = 0.37). This study suggests that breastfeeding neither impacts the sporadic development nor is associated with a decrease in the severity of nonhereditary RB as measured by age at diagnosis, stage of disease, ocular prognosis, and extraocular spread. A further exploration into the impact of diet on children who develop RB is warranted.

Inter-eye genomic heterogeneity in bilateral retinoblastoma via aqueous humor liquid biopsy.

Germline alterations in the RB1 tumor suppressor gene predispose patients to develop retinoblastoma (RB) in both eyes. While similar treatment is given for each eye, there is often a variable therapeutic response between the eyes. Herein, we use the aqueous humor (AH) liquid biopsy to evaluate the cell-free tumor DNA (ctDNA) from each eye in a patient with bilateral RB. Despite the same predisposing germline RB1 mutation, AH analysis identified a different somatic RB1 mutation as well as separate and distinct chromosomal alterations in each eye. The longitudinal alterations in tumor fraction (TFx) corresponded to therapeutic responses in each eye. This case demonstrates that bilateral RB tumors develop separate genomic alterations, which may play a role in tumorigenesis and prognosis for eye salvage. Identifying these inter-eye differences without the need for enucleated tumor tissue may help direct active management of RB, with particular usefulness in bilateral cases.

Comprehensive Somatic Copy Number Analysis Using Aqueous Humor Liquid Biopsy for Retinoblastoma.

Aqueous humor (AH) liquid biopsy has been established as a surrogate tumor biopsy for retinoblastoma (RB). Previous AH studies have focused on highly recurrent RB somatic copy number alterations (SCNAs) including gain of 1q, 2p, 6p, and loss of 13q and 16q. In this retrospective study, we provide a comprehensive, whole-genome analysis of RB SCNAs and evaluate associated clinical features for 68 eyes of 64 RB patients from whom AH was obtained between December 2014 and October 2020. Shallow whole-genome sequencing of AH cell-free DNA was performed to assess for SCNAs. The prevalence of specific non-highly recurrent SCNAs, such as 20q gain and 8p loss, differed between primarily and secondarily enucleated eyes. Increases in chromosomal instability predict more advanced seeding morphology (p = 0.015); later age of diagnosis (p < 0.0001); greater odds of an endophytic tumor growth pattern (without retinal detachment; p = 0.047); tumor heights >10 mm (p = 0.09); and containing 6p gain, a biomarker of poor ocular prognosis (p = 0.004). The AH liquid biopsy platform is a high-yield method of whole-genome RB SCNA analysis, and SCNAs are associated with numerous clinical findings in RB eyes. Prospective analyses are encouraged to further elucidate the clinical relevance of specific SCNAs in RB.

Lag Time between Onset of First Symptom and Treatment of Retinoblastoma: An International Collaborative Study of 692 Patients from 10 Countries.

BACKGROUND: The relationship between lag time and outcomes in retinoblastoma (RB) is unclear. In this study, we aimed to study the effect of lag time between onset of symptoms and diagnosis of retinoblastoma (RB) in countries based on their national-income and analyse its effect on the outcomes. METHODS: We performed a prospective study of 692 patients from 11 RB centres in 10 countries from 1 January 2019 to 31 December 2019. RESULTS: The following factors were significantly different among different countries based on national-income level: age at diagnosis of RB (p = 0.001), distance from home to nearest primary healthcare centre (p = 0.03) and mean lag time between detection of first symptom to visit to RB treatment centre (p = 0.0007). After adjusting for country income, increased lag time between onset of symptoms and diagnosis of RB was associated with higher chances of an advanced tumour at presentation (p < 0.001), higher chances of high-risk histopathology features (p = 0.003), regional lymph node metastasis (p < 0.001), systemic metastasis (p < 0.001) and death (p < 0.001). CONCLUSIONS: There is a significant difference in the lag time between onset of signs and symptoms and referral to an RB treatment centre among countries based on national income resulting in significant differences in the presenting features and clinical outcomes.

Establishing the Clinical Utility of ctDNA Analysis for Diagnosis, Prognosis, and Treatment Monitoring of Retinoblastoma: The Aqueous Humor Liquid Biopsy.

Because direct tumor biopsy is prohibited for retinoblastoma (RB), eye-specific molecular biomarkers are not used in clinical practice for RB. Recently, we demonstrated that the aqueous humor (AH) is a rich liquid biopsy source of cell-free tumor DNA. Herein, we detail clinically-relevant molecular biomarkers from the first year of prospective validation data. Seven eyes from 6 RB patients who had AH sampled at diagnosis and throughout therapy with ≥12 months of follow-up were included. Cell-free DNA (cfDNA) from each sample was isolated and sequenced to assess genome-wide somatic copy number alterations (SCNAs), followed by targeted resequencing for pathogenic variants using a RB1 and MYCN custom hybridization panel. Tumoral genomic information was detected in 100% of diagnostic AH samples. Of the seven diagnostic AH samples, 5/7 were positive for RB SCNAs. Mutational analysis identified RB1 variants in 5/7 AH samples, including the 2 samples in which no SCNAs were detected. Two eyes failed therapy and required enucleation; both had poor prognostic biomarkers (chromosome 6p gain or MYCN amplification) present in the AH at the time of diagnosis. In the context of previously established pre-analytical, analytical, and clinical validity, this provides evidence for larger, prospective studies to further establish the clinical utility of the AH liquid biopsy and its applications to precision oncology for RB.

Response criteria for intraocular retinoblastoma: RB-RECIST.

Standardized guidelines for assessing tumor response to therapy are essential for designing and conducting clinical trials. The Response Evaluation Criteria In Solid Tumors (RECIST) provide radiological standards for assessment of solid tumors. However, no such guidelines exist for the evaluation of intraocular cancer, and ocular oncology clinical trials have largely relied on indirect measures of therapeutic response-such as progression-free survival-to evaluate the efficacy of treatment agents. Herein, we propose specific criteria for evaluating treatment response of retinoblastoma, the most common pediatric intraocular cancer, and emphasize a multimodal imaging approach for comprehensive assessment of retinoblastoma tumors in clinical trials.

Cell-Free DNA Tumor Fraction in the Aqueous Humor Is Associated With Therapeutic Response in Retinoblastoma Patients.

Purpose: The aqueous humor (AH) liquid biopsy enables in vivo evaluation of tumor-derived cell-free DNA (cfDNA) from retinoblastoma (RB) eyes. Herein, we test our hypothesis that longitudinal dynamics of AH cfDNA-including tumor fraction (TFx) and somatic copy number alteration (SCNA) amplitude-correspond to therapeutic response. Methods: Eyes with ≥3 AH extractions during intravitreal chemotherapy (IVM) or at secondary enucleation between 2015 to 2019 were included. AH cfDNA was sequenced to assess RB SCNA amplitude; ichorCNA software was used to estimate TFx. Eyes without SCNAs or with TFx < 0.10 across all samples were excluded. Therapeutic responses for each eye were determined from clinical records. Statistical analyses included Mann-Whitney U and Pearson correlation tests. Results: Twenty eyes of 20 patients underwent ≥3 AH extractions; 6 eyes lacked SCNAs or had TFx < 0.10 throughout sampling and were excluded. Clinical progression was associated with significantly higher SCNA amplitudes and TFx values than regression (P ≤ 0.04). Relative increases in TFx (ΔTFx 1.86 ± 2.22) were associated with disease progression, whereas relative decreases in TFx (ΔTFx 0.53 ± 0.36) were associated with disease regression (P < 0.00001). A ≥15% increase in TFx relative to baseline during treatment was associated with an over 90-fold increased likelihood of clinical progression (odds ratio = 90.67, 95% confidence interval = 8.30-990.16, P = 0.0002). TFx and SCNA amplitude were significantly positively correlated throughout sampling (P ≤ 0.002). Conclusions: Longitudinal changes in AH-derived cfDNA TFx and SCNA amplitude are concordant with clinical responses of intraocular RB during active therapy. Translational Relevance: Longitudinal evaluation of AH cfDNA may provide an objective, quantitative way to monitor therapeutic response and disease burden in RB patients.

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.

Chromosome 6p Amplification in Aqueous Humor Cell-Free DNA Is a Prognostic Biomarker for Retinoblastoma Ocular Survival.

Aqueous humor contains tumor-derived cell-free DNA (cfDNA) and can serve as a liquid biopsy for retinoblastoma. We previously associated somatic copy-number alteration (SCNA) 6p gain with a 10-fold increased risk of enucleation. Here we provide a 2-year update to further explore 6p gain as a prognostic biomarker for ocular survival. Patients diagnosed with retinoblastoma from December 2014 to July 2019 from whom aqueous humor was sampled were included. cfDNA was extracted and shallow whole-genome sequencing performed to identify highly recurrent retinoblastoma SCNAs (gain of 1q, 2p, 6p, loss of 13q, 16q). 116 aqueous humor samples from 50 eyes of 46 patients were included: 27 eyes were salvaged, 23 were enucleated. Highly recurrent retinoblastoma SCNAs were found in 66% eyes. 6p gain was the most prevalent SCNA (50% eyes). It was particularly more prevalent in enucleated eyes (73.9%) than in salvaged eyes (29.6%; P = 0.004). 6p gain in aqueous humor cfDNA portended nearly 10-fold increased odds of enucleation (OR = 9.87; 95% confidence interval = 1.75-55.65; P = 0.009). In the enucleated eyes, 6p gain was associated with aggressive histopathologic features, including necrosis, higher degrees of anaplasia, and focal invasion of ocular structures. With extended follow-up and nearly double the aqueous humor samples, we continue to demonstrate 6p gain as a potential prognostic biomarker for retinoblastoma. IMPLICATIONS: Aqueous humor is a high-yield source of tumor-derived DNA in retinoblastoma eyes. Detection of 6p gain in the aqueous humor allows for targeted, patient-centered therapies based on this molecular prognostic marker. Prospective, multicenter studies with aqueous humor sampled from all eyes at diagnosis are warranted to validate these findings.

Variability in retinoblastoma genome stability is driven by age and not heritability.

Retinoblastoma (RB) is a childhood intraocular cancer initiated by biallelic inactivation of the RB tumor suppressor gene (RB1-/- ). RB can be hereditary (germline RB1 pathogenic allele is present) or non-hereditary. Somatic copy number alterations (SCNAs) contribute to subsequent tumorigenesis. Previous studies of only enucleated RB eyes have reported associations between heritability status and the prevalence of SCNAs. Herein, we use an aqueous humor (AH) liquid biopsy to investigate RB genomic profiles in the context of germline RB1 status, age, and International Intraocular Retinoblastoma Classification (IIRC) clinical grouping for both enucleated and salvaged eyes. Between 2014 and 2019, AH was sampled from a total of 54 eyes of 50 patients. Germline RB1 status was determined from clinical blood testing, and cell-free DNA from AH was analyzed for SCNAs. Of the 50 patients, 23 (46.0%; 27 eyes) had hereditary RB, and 27 (54.0%, 27 eyes) had non-hereditary RB. Median age at diagnosis was comparable between hereditary (13 ± 10 months) and non-hereditary (13 ± 8 months) eyes (P = 0.818). There was no significant difference in the prevalence or number of SCNAs based on (1) hereditary status (P > 0.56) or (2) IIRC grouping (P > 0.47). There was, however, a significant correlation between patient age at diagnosis, and (1) number of total SCNAs (r[52] = 0.672, P < 0.00001) and (2) number of highly-recurrent RB SCNAs (r[52] = 0.616, P < 0.00001). This evidence does not support the theory that specific molecular or genomic subtypes exist between hereditary and non-hereditary RB; rather, the prevalence of genomic alterations in RB eyes is strongly related to patient age at diagnosis.

Next-Generation Technologies and Strategies for the Management of Retinoblastoma.

Retinoblastoma (RB) is an inherited retinal disorder (IRD) caused by the mutation in the RB1 gene or, rarely, by alterations in the MYCN gene. In recent years, new treatment advances have increased ocular and visual preservation in the developed world. The management of RB has improved significantly in recent decades, from the use of external beam radiation to recently, more localized treatments. Determining the underlying genetic cause of RB is critical for timely management decisions. The advent of next-generation sequencing technologies have assisted in understanding the molecular pathology of RB. Liquid biopsy of the aqueous humor has also had significant potential implications for tumor management. Currently, patients' genotypic information, along with RB phenotypic presentation, are considered carefully when making treatment decisions aimed at globe preservation. Advances in molecular testing that improve our understanding of the molecular pathology of RB, together with multiple directed treatment options, are critical for developing precision medicine strategies to treat this disease.

The RB1 Story: Characterization and Cloning of the First Tumor Suppressor Gene.

The RB1 gene is the first described human tumor suppressor gene and plays an integral role in the development of retinoblastoma, a pediatric malignancy of the eye. Since its discovery, the stepwise characterization and cloning of RB1 have laid the foundation for numerous advances in the understanding of tumor suppressor genes, retinoblastoma tumorigenesis, and inheritance. Knowledge of RB1 led to a paradigm shift in the field of cancer genetics, including widespread acceptance of the concept of tumor suppressor genes, and has provided crucial diagnostic and prognostic information through genetic testing for patients affected by retinoblastoma. This article reviews the long history of RB1 gene research, characterization, and cloning, and also discusses recent advances in retinoblastoma genetics that have grown out of this foundational work.

Extending far and wide: the role of biopsy and staging in the management of ocular surface squamous neoplasia.

IMPORTANCE: Although the most recent American Joint Committee on cancer staging guidelines for ocular surface squamous neoplasia place a heightened emphasis on biopsy and histopathologic analysis, the interpretation and clinical relevance of these staging criteria are not always clear. We address limitations of using histopathologic analysis to predict clinical outcomes and suggest less-invasive assessments. BACKGROUND: To investigate the impact of histopathologic depth of invasion on outcomes for tumours with the common presentation of multiple structure involvement. DESIGN: Retrospective chart review at tertiary institution. SAMPLES: Of 41 eyes with ocular surface squamous neoplasia between 2012 and 2017, 27 tumours involving multiple ocular structures clinically were included. METHODS: Biopsied tumours were determined to be invasive beyond the basement membrane or non-invasive; non-biopsied tumours were clinically identified with unknown depth of invasion. Outcomes were compared using Fisher's exact or Student's t tests. MAIN OUTCOME MEASURES: Proportion of tumours cured, recurred and/or persisting. RESULTS: Twelve tumours (44%) received primary excisional biopsy, 10 (37%) received chemotherapy without biopsy and 5 (19%) received chemotherapy and biopsy. Clinical diagnosis was correct in all biopsied cases. While there were no significant differences in outcomes between invasive vs non-invasive tumours or treatments, there was a trend toward larger basal diameter in recurrent tumours regardless of treatment. CONCLUSIONS AND RELEVANCE: When ocular surface squamous neoplasia tumours with similar clinical involvement were compared, histopathologic depth of invasion was not predictive of clinical outcomes. Future staging criteria may consider the potential of largest basal dimension for more accurate prognostication.

Conjunctival Squamous Neoplasia: Staging and Initial Treatment.

PURPOSE: To evaluate the clinical relevance of the American Joint Committee on Cancer (AJCC) classification in the initial management of squamous neoplasia of the conjunctiva. METHODS: This retrospective study enrolled 95 histopathologically proven cases of treatment-naive conjunctival squamous neoplasia. Tumors were classified into 4 histological groups: conjunctival intraepithelial neoplasia (CIN) with mild dysplasia (grade 1/3), moderate dysplasia (grade 2/3), severe dysplasia (grade 3/3 or carcinoma in situ), and invasive squamous cell carcinoma (SCC). Clinical findings such as tumor location, largest basal diameter, growth pattern, and adjacent structures involved were recorded. RESULTS: CIN was observed in 74 cases (78%), and SCC was noted in 21 cases (22%). Based on the AJCC classification, all the 74 cases of CIN were classified as Tis (tumor in situ). Among the invasive SCC, there were 3 T1 tumors, 2 T2 tumors, and 16 T3 tumors. Complete excision with or without adjuvant therapy was selected as initial treatment in 80% of cases (76/95). Two cases of SCC with scleral invasion were treated using brachytherapy. CONCLUSIONS: The AJCC stage does not correlate with the initial treatment of CIN. The AJCC T3 category should be reviewed to differentiate diffuse SCCs with broad surface extension from tumors with deep scleral invasion.