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Aqueous humor from eyes with active retinoblastoma contains tumor-derived cell-free DNA. Single retrospective case report. A 13-year-old girl with acute right eye pain and redness was diagnosed with hypertensive anterior uveitis. Following initial management, she was referred to ocular oncology for an atypical clinical picture. Multiple seeds were noted 360 degrees in the anterior chamber, at the equator of the lens and canal of Petit, and ultrasound biomicroscopy identified a temporal pars plana lesion. While aqueous humor cytology was inconclusive for malignancy, targeted next-generation sequencing of aqueous cell-free DNA identified biallelic RB1 full gene deletion, confirming the diagnosis of retinoblastoma. Partial regression followed three cycles of systemic carboplatin, etoposide, and vincristine and three intracameral melphalan injections. Four months later, she had recurrence of the primary tumor and increase in seeding and received the investigational sustained release episcleral topotecan chemoplaque. Stable regression was achieved to 28-month follow-up, with no detectable aqueous cell-free DNA. RB1 sequencing analysis of tumor-derived cell-free DNA from aqueous humor can confirm the diagnosis of retinoblastoma in cases of diagnostic uncertainty. [ABSTRACT FROM AUTHOR]

Objective To analyse ocular and systemic findings of patients presenting with systemic metastasis. Methods and analysis It is an international, multicentre, internet-enabled, registry-based retrospective data analysis. Patients were diagnosed between 2001 and 2011. Data included: primary tumour dimensions, extrascleral extension, ciliary body involvement, American Joint Committee on Cancer (AJCC)-tumour, node, metastasis staging, characteristics of metastases. Results Of 3610 patients with uveal melanoma, 69 (1.9%; 95% CI 1.5 to 2.4) presented with clinical metastasis (stage IV). These melanomas originated in the iris, ciliary body and choroid in 4%, 16% and 80% of eyes, respectively. Using eighth edition AJCC, 8 (11%), 20 (29%), 24 (35%), and 17 (25%) belonged to AJCC T-categories T1-T4. Risk of synchronous metastases increased from 0.7% (T1) to 1.5% (T2), 2.6% (T3) and 7.9% (T4). Regional lymph node metastases (N1a) were detected in 9 (13%) patients of whom 6 (67%) had extrascleral extension. Stage of systemic metastases (known for 40 (59%) stage IV patients) revealed 14 (35%), 25 (63%) and 1 (2%) had small (M1a), medium-sized (M1b) and large-sized (M1c) metastases, respectively. Location of metastases in stage IV patients were liver (91%), lung (16%), bone (9%), brain (6%), subcutaneous tissue (4%) and others (5%). Multiple sites of metastases were noted in 24%. Compared with the 98.1% of patients who did not present with metastases, those with synchronous metastases had larger intraocular tumours, more frequent extrascleral extension, ciliary body involvement and thus a higher AJCC T-category. Conclusions Though higher AJCC T-stage was associated with risk for metastases at diagnosis, even small T1 tumours were stage IV at initial presentation. The liver was the most common site of metastases; however, frequent multiorgan involvement supports initial whole-body staging. [ABSTRACT FROM AUTHOR]

Frequency of somatic and germ-line mosaicism has been studied in retinoblastoma and implications for genetic counseling have been considered. An evaluation has been made of 156 families with retinoblastoma. In these families the initial oncogenic mutations in the retinoblastoma gene had been found. In about 10% of the families mosaicism for the initial mutation in the retinoblastoma gene was documented in the proband or in one of the parents of the proband. Germ-line DNA from two mosaic fathers was analyzed. Data suggest that mosaicism is more common that generally believed especially in disorders like retinoblastoma in which a high proportion of cases come from new mutations. The possibility of mosaicism should be considered in genetic counseling of newly identified retinoblastoma families. Genetic tests of germ-line DNA can give valuable information not found in analysis of somatic, leukocyte, DNA.

Abstract Background Most human cancers show inactivation of both pRB- and p53-pathways. While retinoblastomas are initiated by loss of the RB1 tumor suppressor gene, TP53 mutations have not been found. High expression of the p53-antagonist MDM2 in human retinoblastomas may compromise p53 tumor surveillance so that TP53 mutations are not selected for in retinoblastoma tumorigenesis. We previously showed that p14ARF protein, which activates p53 by inhibiting MDM2, is low in retinoblastomas despite high mRNA expression. Methods In human fetal retinas, adult retinas, and retinoblastoma cells, we determined endogenous p14ARF mRNA, ARF protein, and miR-24 expression, while integrity of p53 signalling in WERI-Rb1 cells was tested using an adenovirus vector expressing p14ARF. To study p14ARF biogenesis, retinoblastoma cells were treated with the proteasome inhibitor, MG132, and siRNA against miR-24. Results In human retinoblastoma cell lines, p14ARF mRNA was disproportionally high relative to the level of p14ARF protein expression, suggesting a perturbation of p14ARF regulation. When p14ARF was over-expressed by an adenovirus vector, expression of p53 and downstream targets increased and cell growth was inhibited indicating an intact p14ARF-p53 axis. To investigate the discrepancy between p14ARF mRNA and protein in retinoblastoma, we examined p14ARF biogenesis. The proteasome inhibitor, MG132, did not cause p14ARF accumulation, although p14ARF normally is degraded by proteasomes. miR-24, a microRNA that represses p14ARF expression, is expressed in retinoblastoma cell lines and correlates with lower protein expression when compared to other cell lines with high p14ARF mRNA. Transient over-expression of siRNA against miR-24 led to elevated p14ARF protein in retinoblastoma cells. Conclusions In retinoblastoma cells where high levels of p14ARF mRNA are not accompanied by high p14ARF protein, we found a correlation between miR-24 expression and low p14ARF protein. p14ARF protein levels were restored without change in mRNA abundance upon miR-24 inhibition suggesting that miR-24 could functionally repress expression, effectively blocking p53 tumor surveillance. During retinal tumorigenesis, miR-24 may intrinsically compromise the p53 response to RB1 loss.