Ocular melanoma: relatively rare but requiring respect

Immunoembolization for the Treatment of Uveal Melanoma Hepatic Metastases

Uveal melanoma is the most common primary intraocular tumor in adults. Approximately 50% of patients develop metastatic disease despite successful treatment of the primary eye tumor. The liver is the most common site of metastatic disease occurring in more than 90% of patients. Clinical prognosis is dependent on the ability to control the growth of liver tumors. Locoregional therapies play an important role in stabilizing liver metastases, prolonging survival for patients with metastatic uveal melanoma. As overall survival is prolonged, the development of extrahepatic disease becomes more common. Immunoembolization, a form of liver-directed therapy, not only focuses on treating hepatic metastases by stimulating the local immune system to suppress the growth of liver tumors, but it potentially generates a systemic immune response delaying the growth of extrahepatic metastases as well. The following article discusses immunoembolization for the treatment of metastatic uveal melanoma including the rationale, mechanism of action, indications, contraindications, outcomes, and associated toxicities.

Monte Carlo investigation of dose distribution of uniformly and non-uniformly loaded standard and notched eye plaques

To investigate the effect of using non-uniform loading and notched plaques on dose distribution for eye plaques. Using EGSnrc Monte Carlo (MC) simulations, we investigate eye plaque dose distributions in water and in an anatomically representative eye phantom. Simulations were performed in accordance with TG43 formalism and compared against full MC simulations which account for inter-seed and inhomogeneity effects. For standard plaque configurations, uniformly and non-uniformly loaded plaque dose distributions in water showed virtually no difference between each other. For standard plaque, the MC calculated dose distribution in planes parallel to the plaque is narrower than the TG43 calculation due to attenuation at the periphery of the plaque by the modulay. MC calculated the dose behind the plaque is fully attenuated. Similar results were found for the notched plaque, with asymmetric attenuation along the plane of the notch. Cumulative dose volume histograms showed significant reductions in the calculated MC doses for both tumor and eye structures, compared to TG43 calculations. The effect was most pronounced for the notch plaque where the MC dose to the optic nerve was greatly attenuated by the modulay surrounding the optic nerve compared to the TG43. Thus, a reduction of optic nerve D95% from 14 to 0.2 Gy was observed, when comparing the TG43 calculation to the MC result. The tumor D95% reduced from 89.2 to 79.95 Gy for TG43 and MC calculations, respectively. TG43 calculations overestimate the absolute dose and the lateral dose distribution of both standard and notched eye plaques, leading to the dose overestimation for the target and organs at risk. The dose matching along the central axis for the non-uniformly loaded plaques to that of uniformly loaded ones was found to be sufficient for providing comparable coverage and can be clinically used in eye-cancer-busy centers.

Hydrogen nanobubbles: A novel approach toward radio-sensitization agents

BACKGROUND

Ocular melanoma is a rare kind of eye malignancy that threatens the patient's eyesight. Radiotherapy and surgical removal are the most commonly used therapeutic modalities, and nanomedicine has lately entered this field. Brachytherapy using Ruthenium-106 (106 Ru) ophthalmic plaques has been used for decades to treat ocular melanoma, with the applicator placed on the patient's eyes until the prescribed dose reaches the tumor apex.

PURPOSE

To investigate the efficiency of hydrogen nanobubbles (H2 -NBs) employment during intraocular melanoma brachytherapy using a 106 Ru electron emitter plaque.

METHODS

The Monte Carlo (MC) simulation and experimental investigation using a 3D-designed phantom and thermoluminescence dosimetry (TLD) were employed. Various concentrations of H2 -NBs with a diameter of 100 nm were simulated inside tumor tissue. The results were presented as deposited energy and dose enhancement factor (DEF). An equivalent Resin phantom of the human eyeball was made using AutoCAD and 3D-Printer technologies. The glass-bead TLDs dosimeter were employed and placed inside the phantom.

RESULTS

Using a 1% concentration of H2 -NBs, a DEF of 93% and 98% were achieved at the tumor apex of 10 mm from the experimental setup and MC simulation, respectively. For simulated concentrations of 0.1%, 0.3%, 0.5%, 1%, and 4% H2 -NBs, a maximum dose enhancement of 154%, 174%, 188%, 200%, and 300% were achieved, respectively, and a dose reduction was seen at about 3 mm from the plaque surface.

CONCLUSION

H2 -NBs can be used as an absorbed dose enhancer in 106 Ru eye brachytherapy because of their unique physical characteristics. Reducing plaque implantation time on the patient's eye, reducing sclera absorbed dose, and decreasing the risk of patients' healthy organs irradiation are reported as some of the potential benefits of using H2-NBs.

An unusual case of a pigment epithelial cyst masquerading as a uveal melanoma after zoster ophthalmicus-related iris atrophy

Purpose

To report the case of a 69-year-old male who was referred for a previously unidentified pigmented iris lesion with surrounding iris atrophy masquerading as an iris melanoma.

Observations

A sharply demarcated pigmented lesion extending from the trabecular meshwork to the pupillary margin was identified in the left eye. There was adjacent iris stromal atrophy. Testing was consistent with a cyst-like lesion. The patient later described a prior episode of ipsilateral herpes zoster involving the ophthalmic division of cranial nerve five.

Conclusions and Importance

Iris cysts present an uncommon iris tumor, often going unrecognized especially if located on the posterior iris surface. When they present acutely, as in this case where a previously unidentified cyst was revealed following zoster-induced sectoral iris atrophy, these pigmented lesions can be concerning for malignancy. Accurately identifying iris melanomas and differentiating them from benign iris lesions is imperative.

Copper ionophore elesclomol selectively targets GNAQ/11-mutant uveal melanoma

Unlike cutaneous melanoma, uveal melanoma (UM) is characterized by mutations in GNAQ and GNA11 and remains a fatal disease because there is essentially no effective targeted therapy or immunotherapy available. We report the discovery of the copper ionophore elesclomol as a GNAQ/11-specific UM inhibitor. Elesclomol was identified in a differential cytotoxicity screen of an in-house tool compound library, and its in vivo pharmacological efficacy was further confirmed in zebrafish and mouse UM models. Mechanistically, elesclomol transports copper to mitochondria and produces a large amount of reactive oxygen species (ROS) as Cu(II) is reduced to Cu(I) in GNAQ/11-mutant UM cells, which selectively activates LATS1 kinase in the Hippo signaling pathway and consequently promotes YAP phosphorylation and inhibits its nuclear accumulation. The inactivation of YAP downregulates the expression of SNAI2, which in turn suppresses the migration of UM cells. These findings were cross validated by our clinical observation that YAP activation was found specifically in UM samples with a GNAQ/11 mutation. Furthermore, addition of binimetinib, a MEK inhibitor, to elesclomol increased its synthetic lethality to GNAQ/11-mutant UM cells, thereby overriding drug resistance. This effect was confirmed in an orthotopic xenograft model and in a patient-derived xenograft model of UM. These studies reveal a novel mechanistic basis for repurposing elesclomol by showing that copper homeostasis is a GNAQ/11-specific vulnerability in UM. Elesclomol may provide a new therapeutic path for selectively targeting malignant GNAQ/11-mutant UM.

Second Primary Malignancies following a Diagnosis of Conjunctival Melanoma

BACKGROUND

Although incidence of second primary malignancies (SPMs) has been investigated in patients with cutaneous melanoma and uveal melanoma, limited studies have investigated their occurrence subsequent to conjunctival melanoma (CM). We conducted a retrospective observational study to assess incidence of SPMs in patients with primary CM and to identify associated risk factors.

METHODS

Cases of first primary CM diagnosed from 2000 to 2018 were extracted from the national cancer database Surveillance, Epidemiology, and End Results Program. Standardized incidence ratios (SIR) and excess absolute risk (EAR) of SPMs were calculated compared to a matched cohort from the general population with similar sex, race, age group, and calendar year. EAR was per 10,000 individuals, and a P-value of <0.05 was considered significant.

RESULTS

A total of 471 patients met inclusion criteria, 57 (12.1%) of whom developed second primary malignancies (excluding eye and orbit melanomas) over an average (±SD) follow-up period of 6.8 (±5.0) years. Average age at diagnosis for the overall cohort was 60.2 (±18.6) years. Patients with CM demonstrated a significantly increased risk for overall SPMs relative to the general population, even after excluding eye and orbit melanomas (SIR 1.52; 95% confidence interval [CI], 1.15-1.97; EAR 67.58). Specific sites and malignancy types with increased risk were cutaneous melanoma (SIR 7.95; 95% CI, 4.45-13.12; EAR 45.34), ophthalmic non-melanoma malignancies (SIR 80.92; 95% CI, 2.05-450.84; EAR 3.41), and non-intrahepatic biliary malignancies (SIR 11.72; 95% CI, 1.42-42.32; EAR 6.32). Risk of overall SPMs (excluding eye and orbit melanomas) was significantly increased 5-10 years from diagnosis date.

CONCLUSIONS

Patients with CM had an increased incidence of SPMs compared to the general population. Specifically, these patients developed more cutaneous, ophthalmic non-melanoma, and non-intrahepatic biliary malignancies. These second neoplasms could be due to shared pathophysiology or mutual risk factors. Patients with CM may benefit from surveillance for SPMs, such as annual age-appropriate screenings in the first 10 years after diagnosis.

Use of interferon alpha 2b to manage conjunctival primary acquired melanosis and conjunctival melanoma

Primary acquired melanosis (PAM) is acquired conjunctival pigmentation that can give rise to conjunctival melanoma (CM), a malignant tumor of the bulbar and palpebral conjunctiva or the caruncle. Surgical excision is the treatment of choice for this neoplasm. Topical chemotherapy is also used for patients with PAM with atypia or CM, hand in patients with recurrent or extensive disease, this may be an important option. Of the several chemotherapeutic drugs used, topical interferon alpha 2b (IFN-α2b) has become popular because of its low toxicity. Clinical evidence from case reports and case series supports the efficacy of IFN-α2b as the preferred adjuvant treatment for PAM and CM. In addition, topical IFN-α2b has been successfully applied to melanocytic tumors refractory to other treatments, such as cryotherapy and topical mitomycin C. In patients with locally advanced CM, the combination of IFN-α2b and systemic immunotherapy may serve as an alternative to exenteration. Given the low frequency of CM, long-term multicenter studies are needed to demonstrate the efficacy of IFN-α2b for preventing local recurrence and distant metastasis.

New Therapeutic Approaches for Conjunctival Melanoma-What We Know So Far and Where Therapy Is Potentially Heading: Focus on Lymphatic Vessels and Dendritic Cells

Conjunctival melanoma (CM) accounts for 5% of all ocular melanomas and arises from malignantly transformed melanocytes in the conjunctival epithelium. Current therapies using surgical excision in combination with chemo- or cryotherapy still have high rates for recurrences and metastatic disease. Lately, novel signal transduction-targeted and immune checkpoint inhibitors like cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors, programmed cell death protein-1 (PD-1) receptor inhibitors, BRAF- or MEK-inhibitors for systemic treatment of melanoma have improved the outcome even for unresectable cutaneous melanoma, improving patient survival dramatically. The use of these therapies is now also recommended for CM; however, the immunological background of CM is barely known, underlining the need for research to better understand the immunological basics when treating CM patients with immunomodulatory therapies. Immune checkpoint inhibitors activate tumor defense by interrupting inhibitory interactions between tumor cells and T lymphocytes at the so-called checkpoints. The tumor cells exploit these inhibitory targets on T-cells that are usually used by dendritic cells (DCs). DCs are antigen-presenting cells at the forefront of immune response induction. They contribute to immune tolerance and immune defense but in the case of tumor development, immune tolerance is often prevalent. Enhancing the immune response via DCs, interfering with the lymphatic pathways during immune cell migration and tumor development and specifically targeting tumor cells is a major therapeutic opportunity for many tumor entities including CM. This review summarizes the current knowledge on the function of lymphatic vessels in tumor growth and immune cell transport and continues to compare DC subsets in CM with related melanomas, such as cutaneous melanoma and mucosal melanoma.

Primary orbital melanoma: A report of a case and comprehensive review of the literature

Purpose: To review the clinical features and treatment-associated outcomes of primary orbital melanoma among cases reported in the literature and to present a case treated with orbital exenteration and post-operative radiotherapy.Methods: Case reports and case series on primary orbital melanoma published in the literature between 1980 and 2020 were reviewed. Data collected included patient demographics, presenting ocular symptoms, diagnostic imaging, histology, management, and outcomes.Results: Eighty-eight cases of primary orbital melanoma were reviewed. The average age at presentation was 45 years and 58% of patients were male. The most common presenting symptoms and signs were proptosis (73%), decreased visual acuity (32%), pain (14%), diplopia (15%), and palpable mass (9%). Imaging frequently showed a well-circumscribed enhancing lesion. Diagnosis was made by histology in all cases, and orbital blue nevus was identified in 42%. In the majority of cases, treatment consisted of orbital exenteration (54%) or excision (38%). Adjuvant radiotherapy was given in 47% of cases. For the 72 patients with reported outcomes, 36% had metastases, 15% had local recurrence, and 32% died of metastatic disease. Patients who received surgery and radiotherapy had improved survival compared to those who received surgery alone (p = .01). There was no difference in survival between those who underwent orbital exenteration or excision (p = .16).Conclusions: Primary orbital melanoma is a rare malignancy and should be considered in patients with a history of unilateral proptosis and a well-defined orbital mass on imaging. Surgery remains the mainstay of treatment. Adjuvant radiotherapy may improve patient survival.

Design and optimizing a novel ocular plaque brachytherapy with dual-core of 103Pd and 106Ru

In recent decades, eye plaques of brachytherapy have been extensively used as primary treatment as well as a complementary treatment for ocular cancer. The purpose of this study is the development of the eye plaque brachytherapy throughout a new design of eye plaque by combining the COMS plaque and the CCB BEBIG plaque loaded by IRA1-¹⁰³Pd and ¹⁰⁶Ru, respectively. A new dual-core plaque with a diameter of 20 mm was designed in the way that the BEBIG plaque with a diameter of 20 mm loaded by ¹⁰⁶Ru plate is attached to the COMS plaque with a diameter of 20 mm loaded by 24 of IRA1-¹⁰³Pd seeds. Dose calculations for the new plaque were performed by using the MCNP5 code. Dose calculations of dual-core plaque including ¹⁰³Pd seeds (gamma) and ¹⁰⁶Ru plate (beta) were separately done for the sake of MCNP constraints in gamma and beta particle transfer simultaneously. The new dual-core plaque delivers a much higher dose rate to the tumor compared with every single plaque, while the dose rate reached to healthy tissues is slightly higher than each plaque separately. Of course, this is acceptable because the treatment time reduces and subsequently the error in radiation therapy reduces.

Clinical Diagnosis and Classification: Including Biopsy Techniques and Noninvasive Imaging

Early detection of melanoma is important in improving patient survival. The treatment of melanoma is multidisciplinary and begins by obtaining an accurate diagnosis. The mainstays of melanoma diagnosis include examination of the lesion and surrounding areas and an excisional biopsy so that a pathologic diagnosis can be obtained. The pathology results will help guide treatment recommendations, and some information can be used for prognosis. Further workup of the patient may include laboratory studies and imaging for staging and surveillance.

Protective Effect of Genistein on Cyclin D1 Expression in Malignant Ocular Melanoma Cells

Background:

Ocular melanoma is a disorder that is rarely found but is deadly. Four tissues in the eye that can be attacked by melanoma include the uveal tract, conjunctiva, eyelids, and orbit. Uveal melanoma is the most common case, while melanoma conjunctiva is very rare.

Objective:

This study aimed to investigate the effect of giving genistein on cyclin D1 expression in malignant melanoma.

Methods:

When confluent, CRL1872 malignant melanoma cells will be divided into treatment groups, the group giving genistein dose 25 μM, the group giving genistein a dose of 50 μM, and the group giving genistein a dose of 100 μM. Cyclin D1 analysis was measured by immunofluorescence using confocal laser scan microscopy.

Results:

There was a significant increase in the expression of cyclin D1, in the group given genistein 25 μM and 50 μM (p < 0.05). For the administration of the genistein dose of 100 μM, cyclin D1 expression decreased significantly compared to the control group (p < 0.05).

Conclusion:

It was concluded that genistein had a biphasic effect on cyclin D1 expression in malignant melanoma cells. Thus, genistein at the right dose can be a treatment of malignant melanoma.

Analysis of Clinical Characteristics and Prognosis of Patients With Periocular Malignant Melanoma in Korea

OBJECTIVE

To report the clinical features of 20 patients with malignant melanoma and to evaluate the survival and prognosis of patients with malignant melanoma in Korea.

METHODS AND ANALYSIS

The medical records of 20 patients with malignant melanoma treated between March 2004 and March 2020 were reviewed retrospectively. The demographic data, clinical characteristics, and outcomes were also reviewed. Outcome measures included local recurrence, metastasis, and tumor-related mortality. Prognostic factors associated with recurrence, metastasis, and survival were analyzed using a Cox proportional hazards model.

RESULTS

Among the 20 patients with periocular malignant melanoma, 4 (20%) showed local recurrence during follow-up (6.61 ± 6.36 years). The 1-, 5-, and 10-year recurrence rates were 5%, 10.3%, and 24.1%, respectively. 10 (50%) patients developed distant metastasis, mainly involving lung, brain, parotid gland and spine. The 1-, 5-, and 10-year rates of metastasis were 5%, 10.9%, and 35.7%, respectively. Significantly fewer metastases were detected following initial extensive surgical excision (P = 0.04). 8 (40%) patients died of malignant melanoma. The main risk factor for mortality was tumor thickness (HR: 3.88, P < 0.01). Based on Kaplan-Meier survival estimates, the 1-, 5-, and 10-year tumor-related survival rates were 75.8%, 55.6%, and 55.6%, respectively.

CONCLUSION

Tumor thickness is a significant prognostic factor affecting the survival rate. It is important to reduce the metastatic rate via extensive resection without leaving any residual tumor in the margin during surgery.

Primary Orbital Melanoma: An Investigation of a Rare Malignancy Using the National Cancer Database

OBJECTIVES

Primary orbital melanoma (POM) is a rare disease with limited data on survival and best treatment practices. Here we utilize the National Cancer Database (NCDB) to determine the overall survival (OS) and covariates that influence mortality.

STUDY DESIGN

Retrospective cohort study.

METHODS

All patients diagnosed with POM from 2004 to 2016 were identified in the NCDB. Patient and oncologic data were analyzed using the Kaplan-Meier method and multivariate models for the primary outcome of OS.

RESULTS

A total of 129 patients were identified. Median OS was 36.9 months (95% confidence interval [CI] 24.1-78.7 months) with mean 5-year survival of 42.0% (CI 33.2%-53.2%). Treatments received included surgery alone (43.4%), radiation alone (23.3%), and surgery followed by radiation (20.2%). The multivariate model demonstrated an increased risk of death associated with age over 80 years (hazard ratio [HR] 3.41, CI 1.31-8.86, P = .012), a Charlson-Deyo comorbidity score of 2 or greater (HR 5.30, CI 1.87-15.03, P = .002), and no treatment (HR 2.28, CI 1.03-5.06, P = .042). For every 1 cm increase in tumor size, there was an increased risk of death (HR 1.06, CI 1.00-1.13, P = .039). When compared to surgery alone, no other treatment modality had an effect on OS.

CONCLUSIONS

This study leveraged multiyear data from the NCDB to provide prognostic and demographic information on the largest known cohort of POM cases. Increased age, increased comorbidities, not receiving treatment, and larger tumor size were associated with increased mortality. There was no clear survival advantage for specific treatments.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1790-1797, 2021.

Development of GATE Monte Carlo Code for Simulation and Dosimetry of New I-125 Seeds in Eye Plaque Brachytherapy

Purpose

Dose distributions are calculated by Monte Carlo (MC) simulations for two low-energy models ¹²⁵I brachytherapy source-IrSeed-125 and IsoAid Advantage (model IAI-125A)-loaded in the 14-mm standardized plaque of the COMS during treatment of choroid melanoma.

Methods

In this study, at first, the radial dose function in water around ¹²⁵I brachytherapy sources was calculated based on the recommendations of the Task Group No. 43 American Association of Physicists in Medicine (TG-43U1 APPM) using by GATE code. Then, brachytherapy dose distribution of a new model of the human eye was investigated for a 14-mm COMS eye plaque loaded with these sources with GATE Monte Carlo simulation.

Results

Results show that there are good agreements between simulation results of these sources and reporting measurements and simulations. Dosimetry results in the designed eye phantom for two types of iodine seeds show that the ratios of average dose of tumor to sclera, vitreous, and retina for IrSeed (IsoAid) source are 3.7 (3.7), 6.2 (6.1), and 6.3 (6.3), respectively, which represents the dose saving to healthy tissues. The maximum percentage differences between DVH curve of IsoAid and IrSeed seeds was about 8%.

Conclusions

Our simulation results show that although new model of the ¹²⁵I brachytherapy source having a slightly larger dimension than IAI-125A, it can be used for eye melanoma treatment because the COMS eye plaque loaded with IrSeed-125 could produce similar results to the IsoAid seeds, which is applicable for clinical plaque brachytherapy for uveal melanoma.

Genomic and transcriptomic landscape of conjunctival melanoma

Conjunctival melanoma (CJM) is a rare but potentially lethal and highly-recurrent cancer of the eye. Similar to cutaneous melanoma (CM), it originates from melanocytes. Unlike CM, however, CJM is relatively poorly characterized from a genomic point of view. To fill this knowledge gap and gain insight into the genomic nature of CJM, we performed whole-exome (WES) or whole-genome sequencing (WGS) of tumor-normal tissue pairs in 14 affected individuals, as well as RNA sequencing in a subset of 11 tumor tissues. Our results show that, similarly to CM, CJM is also characterized by a very high mutation load, composed of approximately 500 somatic mutations in exonic regions. This, as well as the presence of a UV light-induced mutational signature, are clear signs of the role of sunlight in CJM tumorigenesis. In addition, the genomic classification of CM proposed by TCGA seems to be well-applicable to CJM, with the presence of four typical subclasses defined on the basis of the most frequently mutated genes: BRAF, NF1, RAS, and triple wild-type. In line with these results, transcriptomic analyses revealed similarities with CM as well, namely the presence of a transcriptomic subtype enriched for immune genes and a subtype enriched for genes associated with keratins and epithelial functions. Finally, in seven tumors we detected somatic mutations in ACSS3, a possible new candidate oncogene. Transfected conjunctival melanoma cells overexpressing mutant ACSS3 showed higher proliferative activity, supporting the direct involvement of this gene in the tumorigenesis of CJM. Altogether, our results provide the first unbiased and complete genomic and transcriptomic classification of CJM.

Conjunctival melanoma is an extremely rare form of cancer of the eye that arises from melanocytes–the cells producing the protective pigment melanin–in the outmost layer of the eye: the conjunctiva. This tissue, similarly to the skin, can also be exposed to UV light radiation from the sun. We investigated the genetic background of this rare form of cancer in samples from fourteen patients, by global DNA and RNA sequencing. Our results showed that conjunctival melanoma is genetically very similar to cutaneous melanoma. More precisely, in tumor DNA we detected signs of damage caused by UV light, as well as mutations in the genes BRAF, NF1 and NRAS/HRAS, previously described to be involved in cutaneous melanoma. Analysis of tumor gene expression also revealed similarities between these two types of cancer, some of which could be used as prognostic factors or as indicators of a patients’ response to therapy. In addition, we identified frequent somatic mutations in ACSS3, a gene not yet associated with either conjunctival or cutaneous melanoma, which represents a potential key player in oncogenesis of conjunctival melanoma.

Locoregional Therapies for the Treatment of Uveal Melanoma Hepatic Metastases

Uveal melanoma is the most common primary intraocular malignant tumor in adults. Approximately 50% of patients develop metastatic disease of which greater than 90% of patients develop hepatic metastases. Following the development of liver tumors, overall survival is dismal with hepatic failure being the cause of death in nearly all cases. To prolong survival for patients with metastatic uveal melanoma, controlling the growth of hepatic tumors is essential. This article will discuss imaging surveillance following the diagnosis of primary uveal melanoma; locoregional therapies used to control the growth of hepatic metastases including chemoembolization, immunoembolization, radioembolization, percutaneous hepatic perfusion, and thermal ablation; as well as currently available systemic treatment options for metastatic uveal melanoma.

Uveal melanoma: progress in molecular biology and therapeutics

Uveal melanoma (UM) is the most common intraocular malignancy in adults. So far, no systemic therapy or standard treatment exists to reduce the risk of metastasis and improve overall survival of patients. With the increased knowledge regarding the molecular pathways that underlie the oncogenesis of UM, it is expected that novel therapeutic approaches will be available to conquer this disease. This review provides a summary of the current knowledge of, and progress made in understanding, the pathogenesis, genetic mutations, epigenetics, and immunology of UM. With the advent of the omics era, multi-dimensional big data are publicly available, providing an innovation platform to develop effective targeted and personalized therapeutics for UM patients. Indeed, recently, a great number of therapies have been reported specifically for UM caused by oncogenic mutations, as well as other etiologies. In this review, special attention is directed to advancements in targeted therapies. In particular, we discuss the possibilities of targeting: GNAQ/GNA11, PLCβ, and CYSLTR2 mutants; regulators of G-protein signaling; the secondary messenger adenosine diphosphate (ADP)-ribosylation factor 6 (ARF6); downstream pathways, such as those involving mitogen-activated protein kinase/MEK/extracellular signal-related kinase, protein kinase C (PKC), phosphoinositide 3-kinase/Akt/mammalian target of rapamycin (mTOR), Trio/Rho/Rac/Yes-associated protein, and inactivated BAP1; and immune-checkpoint proteins cytotoxic T-lymphocyte antigen 4 and programmed cell-death protein 1/programmed cell-death ligand 1. Furthermore, we conducted a survey of completed and ongoing clinical trials applying targeted and immune therapies for UM. Although drug combination therapy based on the signaling pathways involved in UM has made great progress, targeted therapy is still an unmet medical need.

Conjunctival Melanoma: Current Treatments and Future Options

Conjunctival melanoma is a rare tumor of the conjunctival epithelium with a heterogenous clinical presentation and a propensity for regional and distant metastatic spread. Guidelines for the treatment of local conjunctival melanoma are well-established, but there are no standard efficacious therapies for metastatic disease. Given that conjunctival melanoma is genetically similar to cutaneous melanoma and mucosal melanomas, targeted therapies effective in the treatment of these diseases, such as BRAF inhibitors and KIT inhibitors, may be effective in the treatment of patients with metastatic conjunctival melanoma. Other targeted small-molecule drugs in the drug development pipeline for the treatment of more prevalent melanomas could also be applicable to conjunctival melanoma. Furthermore, systemic immunotherapy treatments that are now a mainstay in the treatment of cutaneous melanoma, such as programmed cell death-1 and cytotoxic T lymphocyte-associated antigen-4 inhibitors, could also stand to benefit patients with metastatic conjunctival melanoma. Limited case reports provide clues about the effectiveness of both targeted small-molecule inhibitors and immunotherapy in patients with advanced local and metastatic conjunctival melanoma and give credence to the argument that conjunctival melanoma patients should be included in major trials studying new therapies in both cutaneous and mucosal melanomas where applicable.

miR-652 Promotes Proliferation and Migration of Uveal Melanoma Cells by Targeting HOXA9

Background

Dysregulation of the microRNA (miRNA) network is a typical feature of many cancers. However, the key specific miRNAs involved in uveal melanoma carcinogenesis are largely unknown.

Material/Methods

RT-qPCR was used to detected miR-652 expression in uveal melanoma tissues and cell lines. miR-652 inhibitor was transfected into uveal melanoma cells to decrease miR-652 expression and determine the biological role of miR-652 by CCK-8 and wound healing assays. Bioinformatic analysis and dual luciferase reporter assay were used to predict and validate the target gene of miR-652. HOXA9 siRNA was transfected into cells to confirm that miR-652 relies on regulation of HOXA9 to regulate cell proliferation and migration.

Results

RT-qPCR showed that miR-652 was overexpressed in uveal melanoma cell lines (MUM-2B, MEL270) compared with melanocyte cells (ARPE-19). Overexpression of miR-652 was also observed in uveal melanoma compared to paired non-tumor tissues. Downregulation of miR-652 inhibited the cell proliferation ability and migration ability of uveal melanoma cells. Using bioinformatic analysis, HOXA9 was found to be a potential target gene of miR-652. The direct regulation of HOXA9 by miR-652 was experimentally validated in uveal melanoma cells by dual luciferase assay and Western blotting. We also observed that miR-652 promoted HIF-1α signaling via repression of HOXA9 in uveal melanoma cells. Silencing of HOXA9 attenuated the miR-652 inhibitor decreased cell growth rate and decreased migration ability in uveal melanoma cells.

Conclusions

Our data demonstrate an oncogenic role of miR-652 in uveal melanoma, showing that miR-652 may be a useful biomarker for prediction of prognosis for patients with uveal melanoma.

A novel quality assurance system for eye plaque brachytherapy

Eye Plaque brachytherapy pre-treatment quality assurance (QA) conducted clinically involves an activity verification of individual seeds via well chamber and does not include a physical measurement of dose-rate of the final assembly. A novel spectroscopic, dose-rate detection system, was evaluated for pre-treatment QA of eye plaque brachytherapy. The system includes a water phantom with sterility management. The system was calibrated using a known-activity I-125 seed, measured at 1 cm in water along the radial axis, compared to TG-43 U1 calculations and verified over a number of distances. A depth dose curve was acquired for a clinical, mixed activity eye plaque and two 'error' plaques. The probe was stepped from a water equivalent source to a detector distance (SDD) of 2.5 to 12 mm along the plaque central axis. The latter measurements aimed to characterise the sensitivity of the system. The calculated and measured single-seed dose-rates agreed to within 0.5 cGy/h from a SDD of 3 mm and above. The clinical plaque showed agreement between measured and treatment planning system (TPS) calculated dose-rates within 2%. Sensitivity testing resulted in a maximum deviation from TPS data of 18%, therefore was able to detect the presence of packing errors. The dose-rate detection system was successfully evaluated for verification of I-125 based eye plaques without compromising sterility, allowing for quick pre-treatment, dose-rate verification of patient-ready plaques. Its agreement with TPS data for the unmodified plaque and its deviation when introducing errors confirms the approach suggested is a viable QA tool.

Novel therapeutic strategies and targets in advanced uveal melanoma

PURPOSE OF REVIEW

Currently, there are no U.S. Food and Drug Administration-approved or effective treatment options for advanced-stage uveal melanoma. In this article, we focus on therapeutic targets in pathways/mechanisms associated with common mutations in uveal melanoma. We review the challenges associated with targeting of these pathways and novel treatment strategies.

RECENT FINDINGS

Common mutations that promote uveal melanoma initiation and progression include alterations in G protein subunit alpha q/11 (GNAQ/GNA11) and breast cancer gene 1-associated protein 1 (BAP1). Mutant GNAQ/GNA11 induces constitutive activation of tumorigenic pathways such as extracellular signal-regulated kinase (ERK)1/2 and yes-associated protein. Inhibition of mitogen-activated protein kinase kinase (MEK) downstream of ERK1/2, however, was shown in trials to have limited clinical benefit. Recent reports suggested that combination therapies of MEK inhibition and modulators of mechanisms of drug resistance may improve tumor responses to MEK inhibitors. BAP1 has been shown to be involved in modulating chromatin dynamics and deubiquitination of proteins. Hence, epigenetic inhibitors are being investigated in BAP1 mutant uveal melanoma. However, other functions of BAP1, such as in DNA damage repair and cell cycle regulation, indicate additional targets for treatment of BAP1 mutant uveal melanoma. In addition, the frequent delayed development of uveal melanoma macrometastases is likely due to cellular dormancy mechanisms. Nuclear receptor subfamily 2, group F, member 1 and transforming growth factor beta 2 were among factors that have been shown in other cancers to induce dormant phenotypes.

SUMMARY

Findings from studies in uveal melanoma and in other cancers provide evidence for potential strategies that may be tested preclinically and clinically in advanced-stage uveal melanoma to improve treatment outcome and overall survival of patients.

Uveal Melanoma in Ireland

Purpose

To report the clinical features and epidemiology of uveal melanoma in Ireland.

Methods

This was an observational study of 253 patients with a new diagnosis of uveal melanoma between June 2010 and December 2015. Main outcome measures included demographics, clinical features, age-adjusted incidence, relative survival, overall survival, and distant metastases-free survival.

Results

The mean patient age was 61.7 years. Tumour location was choroidal in 82%, ciliochoroidal in 9%, iridociliary in 2%, and iris in 7%. Treatment modalities included brachytherapy (ruthenium-106 and iodine-125 [64%]), enucleation (27%), and proton beam radiation (8%). The mean age-adjusted incidence of uveal melanoma in Ireland from 2010 to 2015 was 9.5 per million of the population (95% confidence interval [CI]: 8.4-10.7). Four-year relative survival was 81.3% (95% CI: 72.8-87.3). Four-year overall survival was 84% (95% CI: 78-90) and 4-year distant metastases-free survival was 79% (95% CI: 73-86).

Conclusion

Based on this data, the incidence of uveal melanoma in Ireland is high when compared with other reported incidence rates in Europe and worldwide. Relative and observed survival were in keeping with other reported European survival rates.

Conjunctival Melanoma - Epidemiological Trends and Features

Conjunctival melanoma is a rare but sight and life threatening malignancy. It accounts for 2%-5% of all ocular tumours and 5%-7% of all ocular melanomas with an incidence of 0.2-0.8 per million in the Caucasian population with rare cases reported in the non-Caucasians. In recent decades the incidence of uveal melanoma has been relatively stable whilst conjunctival and cutaneous melanoma have shown increasing incidence which may be connected to the result of environmental exposure to ultraviolet light. The dissimilarity in incidence between light and dark pigmented individuals observed in conjunctival melanomas compared to uveal and cutaneous melanomas may be related to differences in their histological structures and genetic profile. Recent molecular biological studies support the fact that each type of melanoma undergoes its own molecular changes and has characteristic biological behaviour. Further studies are required for each type of melanoma in order to ascertain their individual etiology and pathogenesis and based on this knowledge develop relevant preventative and treatment procedures.

Intraprocedural 3D perfusion measurement during chemoembolisation with doxorubicin-eluting beads in liver metastases of malignant melanoma

OBJECTIVES

To study feasibility and validity of a new software application for intraprocedural assessment of perfusion during chemoembolisation of melanoma metastases.

METHODOLOGY

In a prospective phase-II trial, ten melanoma patients with liver-only metastases underwent chemoembolisation with doxorubicin-eluting beads (DEBDOX-TACE). Tumour perfusion was evaluated immediately before and after treatment at cone beam computer tomography (CBCT) using a new software application. For control and comparison, patients underwent perfusion measurement via contrast-enhanced multidetector CT (MDCT) before and after treatment.

RESULTS

CBCT showed 94.7 % reduction in perfusion in metastases after DEBDOX-TACE, whereas MDCT showed 96.8 %. Reduction in perfusion after treatment was statistically significant (p < 0.01) for both methods. The additional time needed for data acquisition during treatment was 5 min per case or less; the post-processing data analysis was 10 min or less. Perfusion imaging was associated with additional contrast agent and patient exposure to radiation (dose-length product [DLP]): 18 ml and 394 mGy*cm in CBCT and 100 ml and 446 mGy*cm in MDCT, respectively.

CONCLUSIONS

Reduction in perfusion of melanoma metastases after DEBDOX-TACE can be reliably assessed during the intervention via perfusion software at CBCT. Data acquisition and analysis require additional time but can be easily performed during the treatment.

KEY POINTS

• Tumour perfusion of melanoma metastases can be assessed at cone beam CT. • The software shows a significant decrease of tumour perfusion after DEBDOX-TACE. • Data acquisition and analysis require an acceptable additional time during the procedure. • CBCT requires less radiation exposure and contrast for perfusion study than MSCT. • This software can monitor the course of DEBDOX-TACE in melanoma metastases.

Primary Orbital Melanoma: Presentation, Treatment, and Long-term Outcomes for 13 Patients

BACKGROUND

Periocular melanoma is a rare but often deadly malignancy that arises in the uvea (commonest origin), conjunctiva or orbit (rarest primary site). Melanoma accounts for 5-10% of metastatic/secondary orbital malignancies, but only a tiny proportion of primary orbital neoplasia. Primary orbital melanoma (POM) is exceedingly rare, with approximately 50 cases reported to date.

METHODS

All patients seen in the orbital unit at a tertiary referral hospital (1991-2016) with a biopsy-proven diagnosis of POM were identified from a diagnostic database and were studied. The case notes, imaging, surgical approach, and histology were reviewed.

RESULTS

Thirteen patients (five male; 38%) presented with isolated malignant melanoma of the orbit, for which no other primary site was identified at presentation or during an average follow-up of 44 months (median 22; range 0-13 years). The patients presented between the ages of 40 and 84 years (mean 55.5; median 48 years) and typically gave a short history of rapidly increasing proptosis and eyelid swelling. On the basis of history, a malignant lesion was suspected in most patients and all underwent incisional biopsy, with debulking of the mass in 10 (77%) patients, and skin-sparing exenteration in 3/13 (23%). Ten patients underwent orbital radiotherapy and the survival to date ranged from 9 months to 14 years (mean 55 months; median 23 months); two patients received solely palliative care for widespread disease and one patient refused orbital radiotherapy. Five of the 13 (38%) patients died from the disease.

DISCUSSION

POM is a very rare malignancy, but clinical analysis of this cohort gives insight into disease presentation and prognosis. The tumor typically presents with a rapidly progressive, well-defined mass that is, in some cases, amenable to macroscopically intact excision. Unusual for malignant melanoma, some of these patients can show an unusually long period of quiescent disease after surgical debulking and radiotherapy.

FGF2 promotes metastasis of uveal melanoma cells via store-operated calcium entry

Uveal melanoma (UM), the most common primary intraocular malignancy in adults, is highly metastatic and associated with dismal prognosis. Fibroblast growth factor 2 (FGF2) has been shown to induce cell proliferation and angiogenesis of melanoma and other malignancies. However, the expression of FGF2 in UM and its effects on melanoma cell migration are not well known. In this study, we found FGF2 expression was related to UM histological subtype and presence of metastasis. In vitro experiments showed that FGF2 treatment caused increased horizontal and vertical migration and F-actin cytoskeleton assembly as well as decreased adhesive activity of MUM2B cells, together with increased intracellular calcium concentration and expression of ORAI1 and STIM1 – two key regulatory proteins of store-operated calcium entry (SOCE). The mouse xenograft model showed that MUM2B cells with FGF2 stimulation grew into larger tumor masses and were prone to metastasis. In addition, the SOCE inhibitor 2-aminoethoxydiphenyl borate (2-APB) reversed all of these effects of FGF2. Finally, human UM samples and mouse xenograft model samples were used to confirm the correlation of FGF2 with ORAI1 and STIM1 expression. Taken together, our study suggests that FGF2 promotes metastasis of UM via SOCE.

Giant Orbital Melanoma in a Heroin Abuser

Purpose

The aim of this report was to report a heroin abuser with nondiagnosed giant uveal melanoma infiltrating the orbit and prolapsing through the face.

Methods

We conducted a case report of the patient with giant melanoma.

Results

In March 2013, a 39-year-old male with bleeding from the right side of his face was taken to the Emergency Center of the University Hospital Bratislava by ambulance. The heroin abusing, homeless male who had never been treated before reported a 2-year history of a prolapsed, dark colored mass from his eye. Acute computed tomography confirmed a solid mass 20 × 20 cm prolapsing from the orbit. The patient rejected primary care, accepted only 1 transfusion and left the hospital. Two months later, he was admitted to the hospital due to anemia after many collapses. Liver metastasis was present. Surgical palliative therapy was not possible due to his general status. The patient started fractionated external radiotherapy with 8.0 Gy Co⁶⁰. Histopathological examination of the biopsy specimen showed malignant melanoma of the epitheloid type G2–3. The patient died in December 2013.

Conclusion

Extraorbital formation of a melanoma mass may progress to a giant volume, and without treatment, led to metastases in the liver and to death after 9 months in our patient with anemia.

Dysregulated GPCR Signaling and Therapeutic Options in Uveal Melanoma

Uveal melanoma is the most common primary intraocular malignant tumor in adults and arises from the transformation of melanocytes in the uveal tract. Even after treatment of the primary tumor, up to 50% of patients succumb to metastatic disease. The liver is the predominant organ of metastasis. There is an important need to provide effective treatment options for advanced stage uveal melanoma. To provide the preclinical basis for new treatments, it is important to understand the molecular underpinnings of the disease. Recent genomic studies have shown that mutations within components of G protein-coupled receptor (GPCR) signaling are early events associated with approximately 98% of uveal melanomas.Implications: This review discusses the alterations in GPCR signaling components (GNAQ and GNA11), dysregulated GPCR signaling cascades, and viable targeted therapies with the intent to provide insight into new therapeutic strategies in uveal melanoma. Mol Cancer Res; 15(5); 501-6. ©2017 AACR.

Lentiviral-mediated overexpression of KCTD12 inhibits the proliferation of human uveal melanoma OCM-1 cells

Human potassium channel tetramerization domain containing 12 (KCTD12, also known as Pfetin) is a member of the KCTD family which consists of 26 members. It has been reported that KCTD12 regulates agonist potency and kinetics of GABAB receptor signaling. Proteomic analysis indicates that KCTD12 may be a potential biomarker for the diagnosis and prognosis of gastrointestinal stromal tumors. However, little has been reported concerning the role of KCTD12 in the other tumor types. In the present study, we designed and subcloned N-terminally Flag-tagged human KCTD12 into the pLVX‑Puro vector. We then generated a human uveal melanoma cell line (OCM-1) stably expressing KCTD12. Using this stable cell line, we performed a series of experiments including colony formation, invasion, migration and wound-healing assays, flow cytometry and western blotting. Based on the experimental results, we first demonstrated that KCTD12 effectively suppressed the proliferation of OCM-1 cells and limited the spread of OCM-1 cells. In the flow cytometric analysis, prolongation of the progression of G2/M to G1 phase in the KCTD12-overexpressing OCM-1 cells was observed. In addition, inhibition of KCTD12-overexpressing OCM-1 cell xenograft growth in nude mice was observed. Taken together, KCTD12 may serve as a novel therapeutic target for patients with uveal melanoma.

Advances in the management of conjunctival melanoma

Malignant melanoma of the conjunctiva is a rare but serious condition. Over the last several years, there have been important advances in the classification, diagnosis, and treatment of this condition. Recent cytogenetic and immunohistochemical studies are increasing understanding of its tumorigenesis. Diagnosis, although still made via histopathology, has been aided with imaging techniques such as ultrasound biomicroscopy and anterior segment optical coherence tomography. Primary treatment consists of surgical excision. But adjuvant treatments with cryotherapy, topical chemotherapy, and radiation therapy have shown increased success. Sentinel lymph node biopsy has shown early promise of detecting micro-metastasis. Long term follow-up of patients with conjunctival melanoma with systemic surveillance is necessary to detect recurrences and metastases.

Whole-genome copy-number analysis identifies new leads for chromosomal aberrations involved in the oncogenesis and metastastic behavior of uveal melanomas

To further elucidate the genetic underpinnings of uveal melanoma (UM) and identify new markers that correlate with disease outcome, archival formalin-fixed, paraffin-embedded enucleation specimens from 25 patients with UM and a mean follow-up of 14 years were analyzed for whole-genome copy-number alterations using OncoScan analysis. Copy-number alterations of chromosomes 1, 3, 6, and 8 were also analyzed in these tumors using multiplex ligation-dependent probe-amplification, and mutations in GNAQ, GNA11, and BAP1 were searched for by Sanger sequencing. Our study confirms the previously reported GNAQ and GNA11 mutation frequencies in UMs as well as the presence of monosomy 3 as a factor strongly indicating poor prognosis. Two cases with metastatic disease, but without monosomy of chromosome 3, showed loss of a small region in the distal part of chromosome 2p. Also, UMs leading to metastatic disease had more chromosomal aberrations than those without metastases. Three UMs lacking a GNAQ or a GNA11 mutation showed a gain of chromosome 8q; one of these cases showed extensive chromothripsis. Another case (with suspect lung metastasis) showed focal chromothripsis. Our whole-genome copy-number analysis shows that focal loss of chromosome 2p may be involved in the metastatic spread of UMs without monosomy 3; metastatic UMs carry more chromosomal aberrations than those without metastases; and chromothripsis may play a role in the oncogenesis of UMs, but does not necessarily indicate a poor prognosis. The clinical and particularly diagnostic utility of these findings needs to be corroborated in a larger set of patients with UM.

Hypoxia-inducible factor 1 upregulation of both VEGF and ANGPTL4 is required to promote the angiogenic phenotype in uveal melanoma

PURPOSE

Expression of the hypoxia-inducible factor (HIF)-1-regulated gene product, vascular endothelial growth factor (VEGF), correlates with tumor vascularity in patients with uveal melanoma (UM). While the relationship between HIF-1 and VEGF in cancer is well-studied, their relative contribution to the angiogenic phenotype in UM has not previously been interrogated. Here we evaluate the contribution of HIF-1, VEGF, and a second HIF-1-regulated gene product, angiopoietin-like 4 (ANGPTL4), to angiogenesis in UM.

EXPERIMENTAL DESIGN

UM cells were examined for expression of HIF-1α, VEGF, and ANGPTL4. Their contribution to the angiogenic potential of UM cells was assessed using the endothelial cell tubule formation and directed in vivo angiogenesis assays. These results were corroborated in tissue from UM animal models and in tissue from patients with UM.

RESULTS

Inhibition of VEGF partially reduced tubule formation promoted by conditioned medium from UM cells. Inhibition of ANGPTL4, which was highly expressed in hypoxic UM cells, a UM orthotopic transplant model, a UM tumor array, and vitreous samples from UM patients, inhibited the angiogenic potential of UM cells in vitro and in vivo; this effect was additive to VEGF inhibition.

CONCLUSIONS

Targeting both ANGPTL4 and VEGF may be required for the effective inhibition of angiogenesis in UM.

Preliminary results of contrast-enhanced sonography in the evaluation of the response of uveal melanoma to gamma-knife radiosurgery

PURPOSE

Our aim was to prospectively analyze the use of contrast-enhanced ultrasound (CEUS) in the quantitative assessment of the response of uveal melanoma (UM) to gamma-knife radiosurgery (GKR), investigating whether changes in tumor vascularization precede thickness reduction, which on average occurs at 12 months after GKR.

METHODS

Ten patients with UM treated with GKR underwent sonography (US) and CEUS at baseline and at 3, 6, and 12 months after GKR. The transverse diameter, thickness, and quantitative parameters of the UM (ie, area under the curve in the wash-in phase, wash-in perfusion index, peak enhancement, and wash-in rate) were calculated by using dedicated software and compared by using Wilcoxon's signed-rank test.

RESULTS

The mean tumor thickness on US was significantly less at both 6 (6.6 mm) and 12 months after GKR (5.8 mm) than it was at baseline (8.3 mm; p < 0.05, both comparisons). Compared with baseline data, the median flow quantitative parameters on CEUS were significantly changed as follows: the peak enhancement (in arbitrary units [au]) at baseline was 5 × 10(6) ; 6 months after GKR, it was 2 × 10(1) (p < 0.05), and 12 months after GKR, it was 4 × 10(1) (p < 0.05). The wash-in rate (in au) at baseline was 1 × 10(6) ; 6 months after GKR, it was 2.1 (p < 0.05), and 12 months after GKR, it was 9.3 (p < 0.05). The wash-in perfusion index (in au) at baseline was 2 × 10(7) ; 6 months after GKR, it was 7 × 10(1) (p < 0.05), and 12 months after GKR, it was 1 × 10(2) (p < 0.05). The area under the curve during the wash-in phase (in au) at baseline was 1 × 10(8) ; 12 months after GKR, it was reduced to 6 × 10(2) (p < 0.05).

CONCLUSIONS

At 6 months after GKR, a reduction of tumor thickness, as detected on US, occurred in 6 of the 10 patients, whereas a reduction in all the quantitative parameters measured on CEUS occurred in all 10 patients. However, a larger population is needed to investigate whether CEUS could become the first-choice technique for monitoring the response of UM to GKR.

Management of choroidal melanomas less than 10 mm in largest basal diameter with a 10-mm ruthenium plaque

PURPOSE

To assess tumor control, complications, and vision after brachytherapy for posterior choroidal melanoma <10 mm in largest basal diameter with the 10-mm ruthenium plaque.

METHODS

This was a retrospective cohort study of consecutive choroidal melanomas <10 mm by largest basal diameter in a national ocular oncology service in 1998 to 2010. The median dose was 116 Gy (range, 80-194 Gy) to the apex and 327 Gy (range, 201-824 Gy) to the sclera. The median tumor height and largest basal diameter were 1.9 mm (range, 0.4-5.2 mm) and 7.0 mm (range, 3.3-9.6 mm), respectively. The median distance to disk and foveola was 3.0 mm (range, 0-7.5 mm) and 2.0 mm (range, 0-8.5 mm), respectively.

RESULTS

Four recurrences occurred at a median of 1.4 years (range, 0.6-3.1 years) after irradiation. Five-year cumulative incidence of local recurrence was 9% (95% confidence interval [CI], 3-20). Six patients died at a median of 4.2 years (range, 0.28-8.6 years) after treatment, one with evidence of metastases. At 5 years, 57% (95% CI, 31-79), 72% (95% CI, 58-85), and 97% (95% CI, 88-100) of eyes were free of any maculopathy, radiation maculopathy, and optic neuropathy, respectively. Cumulative incidence of developing low vision and blindness were 17% (95% CI, 7-31) and 3% (95% CI, 2-12) at 5 years, respectively. Thickness >3.0 mm, largest basal diameter >7.0 mm, and location ≤ 1.5 mm of foveola were associated with visual loss.

CONCLUSION

Local tumor control and vision outcomes support the use of 10-mm ruthenium plaques in managing smallest choroidal melanomas.

Detection of GNAQ mutations and reduction of cell viability in uveal melanoma cells with functionalized gold nanoparticles

BACKGROUND

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Early treatment may improve any chances of preventing metastatic disease, but diagnosis of small UM is challenging. Up to 95 % of all UMs carry somatic mutations in the G-coupled proteins GNAQ and GNA11 promoting anchorage-independent growth and proliferation. About 50 % of UMs are fatal. Once metastatic, patients have limited options for successful therapy.

METHODS

We have developed functionalized gold nanoparticles (AuNPs) to visualize transcripts of mutant GNAQ mRNA in living cells. In addition to their suitability as a specific tool for GNAQ mutation detection, we have developed a novel linker that enables conjugation of siRNAs to AuNPs allowing for greater and more rapid intracellular release of siRNAs compared to previously described approaches.

RESULTS

Binding of modified AuNPs to matching target mRNA leads to conformational changes, resulting in a detectable fluorescent signal that can be used for mutation detection in living cells. Knockdown of GNAQ with siRNA-AuNPs effectively reduced downstream signals and decreased cell viability in GNAQ mutant uveal melanoma cells.

CONCLUSION

AuNPs may in future be developed to serve as sensors for mutations of vital importance. The new release system for siRNA-AuNP improves previous systems, which conceivably will be useful for future therapeutic gene regulatory approaches.

Nanoparticle-aided Radiotherapy for Retinoblastoma and Choroidal Melanoma

This work investigates the dosimetric feasibility of employing gold nanoparticles (AuNPs) or carboplatin nano-particles (CNPs) to enhance radiotherapy (RT) treatment efficacy for ocular cancers: retinoblastoma (Rb) and choroidal melanoma (CM), during kV-energy internal and external beam radiotherapy. The results predict that substantial dose enhancement may be achieved by employing AuNPs or CNPs in conjunction with radiotherapy for ocular cancer using kV-energy photon beams. Brachytherapy sources yield higher dose enhancement than the external beam in kV energy range. However, the external beam has the advantage of being non-invasive.

Monte Carlo dosimetry for 103Pd, 125I, and 131Cs ocular brachytherapy with various plaque models using an eye phantom

PURPOSE

To investigate dosimetry for ocular brachytherapy for a range of eye plaque models containing(103)Pd, (125)I, or (131)Cs seeds with model-based dose calculations.

METHODS

Five representative plaque models are developed based on a literature review and are compared to the standardized COMS plaque, including plaques consisting of a stainless steel backing and acrylic insert, and gold alloy backings with: short collimating lips and acrylic insert, no lips and silicone polymer insert, no lips and a thin acrylic layer, and individual collimating slots for each seed within the backing and no insert. Monte Carlo simulations are performed using the EGSnrc user-code BrachyDose for single and multiple seed configurations for the plaques in water and within an eye model (including nonwater media). Simulations under TG-43 assumptions are also performed, i.e., with the same seed configurations in water, neglecting interseed and plaque effects. Maximum and average doses to ocular structures as well as isodose contours are compared for simulations of each radionuclide within the plaque models.

RESULTS

The presence of the plaque affects the dose distribution substantially along the plaque axis for both single seed and multiseed simulations of each plaque design in water. Of all the plaque models, the COMS plaque generally has the largest effect on the dose distribution in water along the plaque axis. Differences between doses for single and multiple seed configurations vary between plaque models and radionuclides. Collimation is most substantial for the plaque with individual collimating slots. For plaques in the full eye model, average dose in the tumor region differs from those for the TG-43 simulations by up to 10% for(125)I and (131)Cs, and up to 17% for (103)Pd, and in the lens region by up to 29% for (125)I, 34% for (103)Pd, and 28% for (131)Cs. For the same prescription dose to the tumor apex, the lowest doses to critical ocular structures are generally delivered with plaques containing (103)Pd seeds.

CONCLUSIONS

The combined effects of ocular and plaque media on dose are significant and vary with plaque model and radionuclide, suggesting the importance of model-based dose calculations employing accurate ocular and plaque media and geometries for eye plaque brachytherapy.

Model-based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom

PURPOSE

To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with(125)I, (103)Pd, or (131)Cs seeds, and to investigate doses to ocular structures.

METHODS

An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye.

RESULTS

Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20-30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%-10% and 13%-14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%-17% and 29%-34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model simulation by up to 16%. In the full eye model simulations, the average dose to the lens is larger by 7%-9% than the dose to the center of the lens, and the maximum dose to the optic nerve is 17%-22% higher than the dose to the optic disk for all radionuclides. In general, when normalized to the same prescription dose at the tumor apex, doses delivered to all structures of interest in the full eye model are lowest for(103)Pd and highest for (131)Cs, except for the tumor where the average dose is highest for (103)Pd and lowest for (131)Cs.

CONCLUSIONS

The eye is not radiologically water-equivalent, as doses from simulations of the plaque in the full eye model differ considerably from doses for the plaque in a water phantom and from simulated TG-43 calculated doses. This demonstrates the importance of model-based dose calculations for eye plaque brachytherapy, for which accurate elemental compositions of ocular media are necessary.

Primary orbital melanoma in association with cellular blue nevus

PURPOSE

To describe 3 cases of primary orbital melanoma associated with either known or subsequently discovered cellular blue nevus.

METHODS

The clinical records and surgical specimens of 3 patients who underwent orbital exenteration for primary orbital melanoma and who had a cellular blue nevus diagnosed before or after detection of the melanoma were retrospectively reviewed.

RESULTS

All 3 patients presented with signs and symptoms of an orbital mass. Subsequent biopsy revealed invasive melanoma. One patient had a known history of congenital cellular blue nevus of the eyelid from which the orbital melanoma originated. The other 2 patients had no known history of cutaneous pigmentation or blue nevus. In these 2 patients, the cellular blue nevus was detected on pathologic review of the orbital exenteration specimen (1 patient) or surgical biopsy specimen (1 patient). All 3 patients underwent total body positron emission tomography/computed tomography, and in all 3 results were negative for other sites of disease involvement. In the 2 patients without a previously known nevus a total body skin check was negative for other primary melanoma lesions. All 3 patients underwent orbital exenteration followed by postoperative radiation therapy.

CONCLUSIONS

Thorough evaluation of biopsy specimens of "primary" orbital melanoma is warranted to ensure identification of any associated blue nevus because blue nevi are precursor lesions for orbital melanoma, and the presence of a blue nevus would support a primary orbital melanoma rather than a metastatic lesion. Patients with a known blue nevus of the periocular skin and ocular adnexa should be monitored closely for signs of malignant transformation.

Transhepatic therapies for metastatic uveal melanoma

Despite successful treatment of the primary tumor, uveal melanoma has a propensity to metastasize to the liver. Prognosis is poor due to the very aggressive nature of these tumors. Because systemic therapies are relatively ineffective and patient survival correlates to disease control in the liver, locoregional therapies provide a means of prolonging survival. We review various techniques including chemoembolization, immunoembolization, radioembolization, arterial fotemustine infusion, and hepatic perfusion for the treatment of liver metastases from uveal melanoma.

Ocular melanoma and the BAP1 hereditary cancer syndrome: implications for the dermatologist

Ocular melanoma is a rare subtype of melanoma, which includes uveal melanoma (UM) and conjunctival melanoma. UM is associated with an increased risk of cutaneous melanoma (CM) in addition to mesothelioma, skin lesions such as epithelioid atypical Spitz tumors, and other internal malignancies due to a germline mutation of the BRCA1-associated protein 1 (BAP1) gene. Such familial risks are important for dermatologists to recognize when screening patients with a history of UM for CM and other malignancies. Molecular genetics further help to elucidate the connections between UM and CM by revealing similarities and differences in important mutations among the melanoma subtypes. Both UM and CM have been shown to harbor germline mutation of BAP1. However, somatic mutations in either GNAQ or GNA11 are unique to UM tumors and could be used as potential markers to differentiate UM from metastatic CM and act as direct therapeutic targets. However, CM-associated BRAF and CDKN2A mutations are rare in UM. This review addresses the clinical features, pathogenesis, and current treatment options of UM, focusing on UM and the BAP1 cancer syndrome to raise awareness of ocular melanoma and its greater role in the predisposition to a hereditary cancer syndrome.