Uveal Melanoma Research Articles

Proton Therapy in Uveal Melanoma

Background/Objectives: Uveal melanoma is the most common primary intraocular malignancy in adults. Treatment options for localized, early-stage disease include enucleation, brachytherapy, and proton beam therapy. This review aims to evaluate the role of proton therapy in the definitive management of uveal melanoma, focusing on its physics, radiobiology, treatment techniques, and associated outcomes. Methods: This narrative review synthesizes current literature on proton therapy for uveal melanoma, emphasizing case selection, treatment efficacy, and side effects. Results: Proton therapy offers significant advantages for thicker uveal melanomas (over 8 mm) due to its unique physical properties, including a rapid dose fall-off that protects critical structures like the retina and optic nerve. Proton therapy may have benefits in tumor control for ocular melanomas given its increased relative biological effectiveness relative to photon therapy for these typically more radioresistant melanomas. Proton therapy may also hold special value for uveal melanomas in close proximity to the optic nerve, as patients are at high risk of visual toxicities with brachytherapy. The review discusses the efficacy of proton therapy across small, medium, and large tumors, along with strategies for improving patient survival through combined systemic therapy. Additionally, the potential of ocular reirradiation with proton therapy is addressed. Conclusions: Proton therapy is an effective treatment for uveal melanoma. It offers advantages over brachytherapy for large tumors, tumors that are close to the optic nerve or insertion of extra-ocular muscles.

Early poliosis- and vitiligo-like depigmentation as an indicator of treatment response in patients with uveal melanoma under tebentafusp therapy.

We report novel findings of early vitiligo- and poliosis-like depigmentation of skin and hair in three patients with uveal melanoma under tebentafusp therapy, which are associated with a good treatment response to tebentafusp.

Posterior uveal biopsy and the trans-scleral Essen forceps biopsy technique.

Differentiating neoplastic and non-neoplastic uveal tumours can present a diagnostic challenge; intra-ocular biopsy may be necessary. The novel trans-scleral Essen Forceps biopsy (TSEB) technique can improve diagnostic yield compared to fine needle aspiration biopsy (FNAB). We present a case demonstrating the technique and its added value. We also review the success rate of TSEB performed at two tertiary eye centres. Retrospective case report and consecutive case series from August 2021 to March 2023. Inclusion criteria were patients who underwent TSEB of posterior uveal lesions from Moorfields Eye Hospital and Sheffield Teaching Hospitals in the United Kingdom. The outcomes were biopsy success rate and complication rate RESULTS: Eleven biopsies met the inclusion criteria. Eight (73%) were successful, which comprised six uveal melanomas, one melanocytoma and one extranodal marginal zone (ENMZ) lymphoma. One TSEB did not yield tissue for histological examination because of perioperative sample handling. Two (18%) biopsies were histologically inconclusive; both were treated as uveal melanoma on clinical grounds or repeat biopsy. The only complication was vitreous loss and retinal hole without retinal detachment in one eye with a very posterior, shallow choroidal lesion. TSEB is an effective alternative to established biopsy techniques, yielding larger tissue samples than FNAB with intact tissue architecture. We recommend adding TSEB to the armamentarium of the ocular oncologist.

Prospective assessment of circulating tumor DNA in patients with metastatic uveal melanoma treated with tebentafusp

Tebentafusp, a bispecific immune therapy, is the only drug that demonstrated an overall survival benefit in patients with metastatic uveal melanoma (MUM). Circulating tumor DNA (ctDNA) has emerged as a potential prognostic and predictive marker in the phase 3 IMCgp100-202 trial using multiplex PCR-based next-generation sequencing (NGS). In this study (NCT02866149), ctDNA dynamics were assessed using droplet digital PCR (ddPCR) in 69 MUM patients undergoing tebentafusp treatment. Notably, 61% of patients exhibited detectable ctDNA before treatment initiation, which was associated with shorter overall survival (median 12.9 months versus 40.5 months for patients with undetectable ctDNA; p < 0.001). Patients manifesting a 90% or greater reduction in ctDNA levels at 12 weeks demonstrated markedly prolonged overall survival (median 21.2 months versus 12.9 months; p = 0.02). Our findings highlight the potential of ddPCR-based ctDNA monitoring as an economical, pragmatic and informative approach in MUM management, offering valuable insights into treatment response and prognosis.

The Histopathology of Chronic "Radiation Conjunctivitis" Shows Diagnostic Features Similar to Those Seen in Radiation Dermatitis, Including Radiation Fibroblasts.

Radiation therapy is a treatment modality for various ocular and ocular adnexal tumors. The histopathology of chronic radiation dermatitis has been well-described. The authors present two cases demonstrating and characterizing "chronic radiation conjunctivitis" which has not been histopathologically illustrated in detail. Retrospective case review of two patients who received proton beam irradiation for an anterior uveal melanoma and external beam radiation for conjunctival lymphoma, and developed leukoplakia and/or thickening of the eyelid margin and symblepharon. Hematoxylin and eosin-stained sections of eyelid margin and conjunctival biopsies as well as clinical histories were reviewed. Conjunctival biopsies in both cases revealed squamous epithelial metaplasia, chronic inflammation and bizarre-appearing stromal cells with hyperchromatic nuclei in a fibrotic/sclerotic stroma, consistent with chronic radiation conjunctivitis. These stromal cells are believed to be the same "radiation fibroblasts" described in chronic radiation dermatitis. The radiation fibroblast is characteristic for the diagnosis of chronic radiation conjunctivitis, as it is in radiation dermatitis. Features of squamous metaplasia of conjunctival epithelium, keratinization, subepithelial fibrosis/sclerosis and chronic inflammation are frequently found but not specific. A detailed history and other ancillary tests help differentiate cicatrizing conjunctival conditions, and biopsy should be performed in the setting of suspicion for a secondary malignancy.

Imipridones inhibit tumor growth and improve survival in an orthotopic liver metastasis mouse model of human uveal melanoma.

Uveal melanoma (UM) is a highly aggressive disease with very few treatment options. We previously demonstrated that mUM is characterized by high oxidative phosphorylation (OXPHOS). Here we tested the anti-tumor, signaling and metabolic effects of imipridones, which are CLPP activators, which inhibit OXPHOS indirectly and have demonstrated safety in patients. We assessed CLPP expression in UM patient samples. We tested the effects of imipridones (ONC201 and ONC212) on the growth, survival, signaling and metabolism of UM cell lines in vitro, and for therapeutic efficacy in vivo in UM liver metastasis models. CLPP expression was detected in primary and mUM patient samples. ONC201 and 212 decreased OXPHOS effectors, inhibited cell growth and migration, and induced apoptosis in human UM cell lines in vitro. ONC212 inhibited OXPHOS, increased metabolic stress and apoptotic pathways, inhibited amino acid metabolism, and induced cell death-related lipids. ONC212 also decreased tumor burden and increased survival in vivo in two UM liver metastasis models. Imipridones are a promising strategy for further testing and development in mUM.

Identification of targetable epigenetic vulnerabilities in uveal melanoma.

Uveal melanoma (UM) is the most prevalent primary intraocular malignancy in adults, which preferentially metastasizes to the liver in approximately half of all cases. Metastatic UM is notoriously resistant to therapy and is almost uniformly fatal. UM metastasis is most strongly associated with mutational inactivation of the BAP1 tumor suppressor gene. Given the role of BAP1 in epigenetic regulation as the ubiquitin hydrolase subunit of the polycomb repressive deubiquitinase (PR-DUB) complex, we conducted high-throughput drug screening using a well-characterized epigenetic compound library to identify new therapeutic vulnerabilities. We identified several promising new lead compounds, in particular the extra-terminal domain protein (BET) inhibitor mivebresib (ABBV-075). Mivebresib significantly improved survival rates in a metastatic uveal melanoma xenograft mouse model and entirely prevented detectable metastases to the bones, spinal cord, and brain. RNA sequencing revealed a notable overlap between the genes and pathways affected by HDAC and BET inhibition, including the reversal of gene signatures linked to high metastatic risk and upregulation of genes associated with a neuronal phenotype. Together, we found that UM cells are particularly vulnerable to class I HDAC and BET inhibition, and highlight the BET inhibitor mivebresib as a promising candidate for further clinical evaluation.

Prognostic Prediction and Immune Microenvironment Characterization in Uveal Melanoma: A Novel Mitochondrial Metabolism-Related Gene Signature.

Uveal Melanoma (UM), a highly aggressive and metastatic intraocular cancer with a strong propensity for liver metastasis, presents limited therapeutic alternatives and unfavorable survival outcomes. Despite its low incidence, the underlying mechanisms of UM pathogenesis and the precise role of mitochondrial metabolism in UM remain inadequately understood. Utilizing Cox proportional hazards regression analysis was used to assess prognostic relevance, and consensus clustering was employed for molecular subtyping. A risk signature was constructed using Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression. We further conducted comparative analyses on clinicopathological characteristics, somatic mutation profiles, drug sensitivity, gene expression patterns, and tumor microenvironment features across different molecular subtypes. Moreover, a nomogram was developed and evaluated. Among 1234 mitochondria metabolism-related genes (MMRGs), 343 were identified as significantly associated with the prognosis of UM. These prognosis-associated MMRGs facilitated the classification of UM into two distinct molecular subtypes, which displayed notable differences in prognosis and pathological staging. Furthermore, an index termed the MMRGs-derived index (MMI) was derived from eight MMRGs, serving as a quantitative measure for poor prognosis risk in UM. MMI demonstrated significant associations with clinicopathological characteristics, somatic mutations, drug responsiveness, and the tumor microenvironment, where higher MMI levels corresponded to worse prognosis, advanced pathological stages, and increased immune cell infiltration. The nomogram built upon MMI provided a potential tool for clinical prognosis assessment in UM patients. This study demonstrated the potential value of MMRGs in predicting prognosis and molecular stratification within UM; however, additional clinical and basic research is warranted to validate their applicability and elucidate the related mechanisms.

Hypoxia-related lncRNA correlates with prognosis and immune microenvironment in uveal melanoma

BackgroundHypoxia-related genes are linked to the prognosis of various solid malignant tumors. However, the role of hypoxia-related long non-coding RNAs (HRLs) in uveal melanoma (UVM) remains unclear. This study aimed to identify HRLs associated with UVM prognosis and develop a novel risk signature to predict patient outcomes.MethodsData from 80 UVM samples were obtained from The Cancer Genome Atlas. Prognostic HRLs were screened using Cox univariate and Pearson correlation analyses. HRL signature were constructed using Lasso analysis, and gene enrichment analysis was performed to explore the association between HRLs and immune features. Cell Counting Kit-8 assay was used to measure the propagation of human uveal melanoma (MuM2B) cells, while tumor invasion and migration were evaluated using Transwell and wound-healing experiments. Inflammatory factors and macrophage polarization were evaluated using quantitative PCR.ResultsIn total, 621 prognostic HRLs were screened and constructed in 12 HRLs. The risk score showed a significant correlation with the survival time of patients with UVM. Additionally, HRL correlated with diverse key immune checkpoints, revealing possible targets for immunotherapy. Immune-related pathways were highly enriched in the high-risk group. LINC02367, a protective HRL, was associated with the tumor microenvironment and survival time of patients with UVM. In vitro, LINC02367 significantly influenced MuM2B proliferation and migration. It also modulated macrophage polarization by regulating inflammatory factor levels, thereby affecting the immune microenvironment.ConclusionsWe developed a novel HRL signature to predict prognosis in patients with UVM. HRLs are potential biomarkers and therapeutic targets for the treatment of UVM.

CYSLTR1 antagonism displays potent anti-tumor effects in uveal melanoma

Uveal Melanoma (UM) is the most common primary intraocular malignancy in adults. Although rare, it is a deadly tumor, with a long-term prognosis of death occurring in more than 50% of the cases. It is characterized by frequent (∼80%) driver mutations in GNAQ and GNA11 genes, both of which are activated by cysteinyl leukotriene receptors (CYSLTRs). CYSLTR1 is upregulated and participated in the progression of several cancers. In the present study, we sought to determine the expression levels of CYSLTR1 in 31 human UM specimens and cell lines (3 primary and 1 metastatic), and its role in the proliferation and viability of these cells by analyzing cell metabolic activity, cell confluence and apoptosis levels. We show that all analyzed UM specimens and cells expressed CYSLTR1 at high levels. Notably, the pharmacological blockage of this receptor, using the inverse agonist MK571, reduced the growth and metabolic activity, and increased the apoptotic cell death of all analyzed UM cell lines. We provide evidence that CYSLTR1 is expressed in human UM and plays a significant role in UM progression behavior. Our data highlight the potential beneficial effects of targeting CYSLTR1 in the control of UM progression.

Uveal melanoma: molecular-genetic mechanisms of arising and the therapeutic approaches

Uveal melanoma (UM) is a tumor of neuroectodermal origin, which results from malignant transformation of melanocytes of the eye vasculature: iris, ciliary body and chorioidea. UM represents up to 5% of all melanoma cases, but it is extremely aggressive, since half of patients with UM develop metastases within the first 1‒2 years after the tumor appearance. Molecular mechanisms of uveal melanoma carcinogenesis are poorly understood, and have already been shown to be different from those of skin melanoma. Activating mutations in the GNAQ and GNA11 genes, encoding the large G protein subunits Gq and G11, respectively, are found in 90% of UM patients. The main signaling cascade leading to the transformation of melanocytes of the uveal tract is the signaling pathway Gaq/PKC/MAPK, and the major regulators of this cascade are targets for the development of drugs. The development of the metastatic form of UM is most often associated with mutations in the genes BAP1, EIF1AX, GNA11, GNAQ, and SF3B1. A combination of a commercial expression test panel of 15 genes and a mutation panel of 7 genes, supplemented with data on the size of the primary tumor, has been shown to be highly effective prognostic signature in prediction the risk of metastases. The risk of metastases determines the choice of therapy and patient follow-up regimen. At the same time, no systemic therapy for the treatment of metastatic UM has been developed to date; new drugs undergoing clinical trials mostly refer to either targeted therapy aimed at inhibiting the protein products of mutant genes, or immunotherapy designed to stimulate an immune response against specific antigens. In addition to these approaches, the review also considers potential therapeutic targets of epigenetic regulation of UM development.

Meeting Report From the 2023 Cure Ocular Melanoma (CURE OM) Global Science Meeting, Philadelphia, PA, November 2023.

The 2023 Cure Ocular Melanoma (CURE OM) Global Science Meeting was held in Philadelphia on November 6, 2023. There is increased awareness and dedicated research in uveal melanoma (UM), but unmet needs remain in the prevention, detection, and treatment of UM. The purpose of this meeting was to provide an international forum for the exchange of research ideas, to allow for discussion of basic science as well as clinical research on UM, and to gather input about advocacy and patient needs.

Standardized A-echography in the diagnostics of eye diseases

The development and the improvement of new imaging methods are current trends in ophthalmology. The literature review is devoted to the use of standardized A-echography in the diagnostics of ocular pathology. The history of the development of this method, the basic principles of obtaining A-sonograms, the features of the qualitative and quantitative assessments of pathological changes in the structures of the eye based on echographic data are presented. Standardized A-echography is most widely used in the diagnostics of vitreoretinal pathology, intraocular mass (choroidal melanoma, choroidal hemangioma, non-tumor formations) and assessment of orbital structures (optic nerve, extraocular muscles, orbital tumors).

Characterization of somatic mutations in sporadic uveal melanoma and uveal melanoma in patients with germline BAP1 pathogenic variants.

Genetic analyses were conducted on tumor samples from 88 patients with uveal melanoma (UM), 6 of whom carry pathogenic germline variants in BAP1. We assessed the frequency, pattern, and prognostic significance of somatic aberrations, and investigated differences between germline BAP1 variant carriers compared to sporadic cases. The frequency of the main oncogenic driver mutations was not significantly different between these groups. Patients with germline BAP1 variants did not have significantly different overall survival compared to the wildtype or somatic BAP1 mutation groups. Patients with a somatic BAP1 mutation (n = 24) had a significantly worse prognosis compared to wildtype (n = 58). All patients with stage III tumors and a somatic BAP1 mutation (n = 7) developed metastasis, however four of 28 stage I-II tumors without metastasis had somatic BAP1 mutations, with observation time >5 years. The tumor from one germline BAP1 carrier (stage IIIC) with a somatic EIF1AX splice variant, has not developed metastasis within a 22-year observation time.

The Impact of Spliceosome Inhibition in SF3B1-Mutated Uveal Melanoma.

Unfortunately, treatment of patients with uveal melanoma (UM) with metastatic disease is limited. Twenty percent of patients with UM harbor a mutation in the splicing factor gene SF3B1, suggesting that aberrant spliceosome function plays a vital role in tumorigenesis. Splicing inhibitors exploit the preferential sensitivity of spliceosome-compromised leukemic cells to these compounds. We studied the effect of the splicing inhibitor E7107 using two UM cell lines and ex vivo cultured SF3B1- and BAP1-mutated primary UM tumor slices. These UM cell lines and ex vivo tumor slices were exposed for 24 hours to different concentrations of E7107. Tumor slices were stained with hematoxylin and eosin (H&E) and incubated with BAP1, MelanA, MIB-1, and caspase-3 antisera. The E7107-exposed UM cell lines exhibited decreased cell viability and increased apoptosis, with the greatest effect on SF3B1-mutated UM cells. A similar effect on UM tumor slices was observed upon exposure to E7107. Additionally, RNA was isolated for differential isoform expression analysis. No significant difference in isoform usage was found genome-wide. However, specific genes were differentially expressed after E7107 treatment in the SF3B1-mutated samples. Moreover, E7107 had the greatest effect on intron retention. This study indicates/suggests that mutated SF3B1 UM cells are more sensitive to the splicing inhibitor E7107 than wild-type SF3B1 UM cells.

A Clinico-Genetic Score Incorporating Disease-Free Intervals and Chromosome 8q Copy Numbers: A Novel Prognostic Marker for Recurrence and Survival Following Liver Resection in Patients with Liver Metastases of Uveal Melanoma

Surgical treatment of liver metastases of uveal melanoma (LMUM) could be proposed for selected patients. This retrospective study examined the prognostic significance of the genetic profiles of liver metastases after LMUM resection. A total of 86 patients treated with resection for LMUM, who underwent genetic analysis of liver metastasis, were included. A multivariable Cox model identified the independent predictors of recurrence-free survival (RFS) and overall survival (OS). The disease-free interval (DFI) and a chromosome 8q surgain (&gt;3 copies) were independent predictors and categorized patients into three risk groups with distinct postoperative prognoses. For the low-, intermediate-, and high-risk scores of recurrence, the median RFS values were 15 months (95% CI: 10–22), 6 months (95% CI: 4–11), and 4 months (95% CI: 2–7), and the median OS values were 86 months (95% CI: 55-NR), 25 months (95% CI: 17–48), and 19 months (95% CI: 12–22), respectively. The predictive accuracy of this scoring system was demonstrated by a mean area under the curve (AUC(t)) of 0.77 (95% CI: 0.65–0.90) for RFS and 0.81 (95% CI: 0.70–0.92) for OS. This novel score, based on a DFI of ≤24 months combined with a chromosome 8q surgain, identifies patients at a high risk of early recurrence and could help clinicians to propose perioperative treatment.

Metastasis-free survival of uveal melanoma by tumour size category based on The Cancer Genome Atlas (TCGA) classification in 1001 cases.

Uveal melanoma (UM) can be classified by tumour size category and by The Cancer Genome Atlas (TCGA) groups (cytogenetic-based, 4-category prognostic classification into Groups A-D). This study was conducted to assess impact on metastasis-free survival (MFS) in UM by tumour size category based on correlation with TCGA classification. Retrospective analysis of 1001 cases categorised as small (0.0-3.0 mm), medium (3.1-8.0 mm) and large (≥8.1 mm), grouped by TCGA classification. Of 1001 cases, TCGA Groups (A/B/C/D) included small (n = 270, 75%/11%/13%/1%), medium (n = 503, 46%/14%/27%/13%) and large (n = 228, 23%/19%/38%/20%) UM. The 5-and 10-year Kaplan-Meier MFS for small UM revealed Group A (98%, 98%), Group B (100%, 100%), Group C (86%, NA) and Group D (100%, NA). For medium UM, the values dropped with Group A (95%, 93%), Group B (90%, 90%), Group C (68%, 38%), and Group D (44%, NA). For large UM, the values dropped further with Group A (94%, 86%), Group B (85%, NA), Group C (40%, 28%), and Group D (23%, NA). Additionally, a comparison (small vs. medium vs. large tumour size category) revealed TCGA low-risk grouping (Groups A or B) in 86% vs. 60% vs. 58% cases with UM. By tumour size category, favourable cytogenetics (Groups A or B) is found in 86% of small tumours, 60% of medium tumours, and 58% of large tumours. The MFS at 10 years for favourable cytogenetics was 98% for small tumours, 92% for medium tumours, and 54% for large tumours. Tumour size category can serve as a surrogate for TCGA.

Plaque Radiotherapy for Ocular Melanoma

Plaque radiotherapy is an effective treatment modality for medium-sized ocular tumors such as uveal melanoma. The authors review the available literature and concisely summarize the current state of the art of ophthalmic plaque brachytherapy. The choice of radioisotope, which includes Ruthenium-106 and Iodine-125, depends on the intended treatment duration, tumor characteristics, and side effect profiles. Ophthalmic plaques may be customized to allow for the delivery of a precise radiation dose by adjusting seed placement and plaque shape to minimize collateral tissue radiation. High dose rate (HDR) brachytherapy, using beta (e.g., Yttrium-90) and photon-emitting sources (e.g., Ytterbium-169, Selenium-75), allows for rapid radiation dose delivery, which typically lasts minutes, compared to multiple days with low-dose plaque brachytherapy. The efficacy of Ruthenium-106 brachytherapy for uveal melanoma varies widely, with reported local control rates between 59.0% and 98.0%. Factors influencing outcomes include tumor size, thickness, anatomical location, and radiation dose at the tumor apex, with larger and thicker tumors potentially exhibiting poorer response and a higher rate of complications. Plaque brachytherapy is effective for selected tumors, particularly uveal melanoma, providing comparable survival rates to enucleation for medium-sized tumors. The complications of plaque brachytherapy are well described, and many of these are treatable.

The BET inhibitor JQ1 suppresses tumor survival by ABCB5-mediated autophagy in uveal melanoma

Uveal melanoma (UM), the most common adult ocular tumor, is aggressive and resistant to treatment, posing threat to patients' lives. The novel, effective therapies and the exploration of chemosensitizer for UM are imperative. The anticancer efficacy was evaluated with and without JQ1 treatment or ABCB5 gene silencing or overexpression. RNA sequencing identified downstream effectors in JQ1-treated cells. Integrated analysis of The Cancer Genome Atlas data (TCGA) and immunohistochemistry (IHC) revealed the oncogenic role of ABCB5. Functional analyses of JQ1 and defective ABCB5 were conducted using flow cytometry, transmission electron microscopy (TEM), IHC and western blot. The effects of JQ1 were validated in a heterotopic tumor model derived from OCM-1 cells. JQ1 inhibited cell proliferation, migration and invasion, induced cell cycle arrest and promoted apoptosis. JQ1 also suppressed the survival of UM in heterotopic tumor model. RNA sequencing indicated that JQ1 down-regulated the expressions of ABCB5 and autophagy-related genes, which was confirmed in vitro and in vivo by western blot. ABCB5, a marker associated with cancer stem cells and chemo-resistance, exhibited heightened expression in UM tissues, linked to immune infiltration. Notably, disrupting ABCB5 expression impeded UM cell proliferation and interfered with autophagy. Moreover, the overexpression of ABCB5 promoted cell proliferation, migration and invasion, and rescued autophagy related gene expression. Of note, JQ1 enhanced the sensitivity of OCM-1 cells to chemotherapy. Thus JQ1 inhibits UM survival via ABCB5-mediated autophagy and enhances chemo-sensitivity, suggesting potential for BET-based approaches in UM clinical management.

Global Incidence and Prevalence in Uveal Melanoma

PurposeThe most common intraocular cancer in adults is uveal melanoma(UM). This study aimed to investigate and report the incidence and prognosis of UM in different regions of the world. MethodsWe retrieved relevant data on UM from the PubMed database and analyzed its global incidence and prognosis. All data was obtained from a national population-based registry, with publication dates ranging from 2013 to 2023. ResultsThe incidence rates of UM vary across different regions: in the United States, rates were 5.1 per million (1993-2008) and 5.2 per million (1973-2013); in Canada, rates ranged from 3.34 per million (1992-2010) to 5.09 per million (2011-2017); in South Korea, the rate was 0.42 per million (1999-2011); in New Zealand, it was 5.56 per million (2000-2020); in Australia, it was 7.6 per million (1982-2014); and in Europe, rates ranged from 3.1 to 5.8 per million (1995-2002). Among European countries, Sweden (5.6 per million (1960-2009)), Germany (6.41 per million (2009-2015)), Poland (6.67 per million (2010-2017)), and the United Kingdom (10 per million (1999-2010)). ConclusionsThe most common site of occurrence for UM is in the choroid. Limited data suggest a stable trend in UM incidence rates across the included countries, but significant differences in incidence rates exist among different countries and regions, with notably lower rates in Asian countries compared to Europe, North America, and Oceania. In general, the incidence rate in males is slightly higher compared to that in females.