Uveal melanoma hepatic metastases mutation spectrum analysis using targeted next-generation sequencing of 400 cancer genes

Immunotherapy for ocular melanoma: a bibliometric and visualization analysis from 1991 to 2022

Background

In recent years, new therapeutic options to overcome the mechanisms of tumor immune suppression be effective in the treatment of cutaneous melanoma. These approaches have also been applied in ocular melanoma. The aim of this study is to present the current status and research hotspots of immunotherapy for ocular melanoma from a bibliometric perspective and to explore the field of immunotherapy for malignant ocular melanoma research.

Methods

In this study, the Web of Science Core Collection database (WoSCC) and Pubmed were selected to search the literature related to immunotherapy of ocular melanoma. Using VOSviewer, CiteSpace, the R package "bibliometrix," and the bibliometric online platform through the construction and visualization of bibliometric networks, the country/region, institution, journal, author, and keywords were analyzed to predict the most recent trends in research pertaining to ocular melanoma and immunotherapy.

Results

A total of 401 papers and 144 reviews related to immunotherapy of ocular melanoma were included. The United States is the main driver of research in the field, ranking first in terms of the number of publications, total citations, and H-index. The UNIVERSITY OF TEXAS SYSTEM is the most active institution, contributing the most papers. Jager, Martine is the most prolific author, and Carvajal, Richard is the most frequently cited author. CANCERS is the most published journal in the field and J CLIN ONCOL is the most cited journal. In addition to ocular melanoma and immunotherapy, the most popular keywords were "uveal melanoma" and "targeted therapy". According to keyword co-occurrence and burst analysis, uveal melanoma, immunotherapy, melanoma, metastases, bap1, tebentafusp, bioinformatics, conjunctival melanoma, immune checkpoint inhibitors, ipilimumab, pembrolizumab, and other research topics appear to be at the forefront of this field's research and have the potential to remain a hot research topic in the future.

Conclusion

This is the first bibliometric study in the last 30 years to comprehensively map the knowledge structure and trends in the field of research related to ocular melanoma and immunotherapy. The results comprehensively summarize and identify research frontiers for scholars studying immunotherapy associated with ocular melanoma.

Molecular profiling of primary uveal melanoma: results of a Polish cohort

There is no published data regarding the molecular alterations of Polish patients with primary uveal melanoma. We performed whole exome sequencing of 20 primary uveal melanomas (UMs), 10 metastasizing and 10 non-metastasizing cases to identify significant molecular alterations. We detected mutations and copy number variants in the BAP1 gene in 50% (10 cases) of the cases. GNA11 mutations were detected in 50% (10 cases) including nine p.Q209L and one p.R183C. GNAQ mutations gene were detected in 40% (8 cases) and all were p.Q209P. SF3B1, EIF1AX, PLCB4 , and PALB2 mutations were detected in one case each. Genetic aberrations of FBXW7 were detected in 55% of cases, with copy number loss of 10 and missense mutation in one. Gain or loss of copy number was observed in 60%, 60%, and 10% of cases in MYC, MLH1 , and CDKN2A genes, respectively. BAP1 and GNAQ tumor suppressor genes are more often mutated in UM with metastasis, while GNA11 mutations are more frequently detected in non-metastasizing tumors. MYC copy gain was present twice as frequently (80% versus 40%) in cases with versus those without metastases. BAP1 mutation correlated with worse overall survival; while GNA11 mutation and CDKN2A loss correlated with better and worse progression-free survival, respectively. We have confirmed BAP1 prognostic potential and documented frequent MYC amplification in metastasizing cases. Although GNA11 mutation and CDKN2A loss significantly correlated with progression-free survival in our study, our sample size is small. The prognostic significance of GNAQ/GNA11 mutation and CDKN2A loss would require further investigation.

Metastatic uveal melanoma: The final frontier

Treatment of primary intraocular uveal melanoma has developed considerably, its driver genes are largely unraveled, and the ways to assess its risk for metastases are very precise, being based on an international staging system and genetic data. Unfortunately, the risk of distant metastases, which emerge in approximately one half of all patients, is unaltered. Metastases are the leading single cause of death after uveal melanoma is diagnosed, yet no consensus exists regarding surveillance, staging, and treatment of disseminated disease, and survival has not improved until recently. The final frontier in conquering uveal melanoma lies in solving these issues to cure metastatic disease. Most studies on metastatic uveal melanoma are small, uncontrolled, retrospective, and do not report staging. Meta-analyses confirm a median overall survival of 10-13 months, and a cure rate that approaches nil, although survival exceeding 5 years is possible, estimated 2% either with first-line treatment or with best supportive care. Hepatic ultrasonography and magnetic resonance imaging as surveillance methods have a sensitivity of 95-100% and 83-100%, respectively, to detect metastases without radiation hazard according to prevailing evidence, but computed tomography is necessary for staging. No blood-based tests additional to liver function tests are generally accepted. Three validated staging systems predict, each in defined situations, overall survival after metastasis. Their essential components include measures of tumor burden, liver function, and performance status or metastasis free interval. Age and gender may additionally influence survival. Exceptional mutational events in metastases may make them susceptible to checkpoint inhibitors. In a large meta-analysis, surgical treatment was associated with 6 months longer median overall survival as compared to conventional chemotherapy and, recently, tebentafusp as first-line treatment at the first interim analysis of a randomized phase III trial likewise provided a 6 months longer median overall survival compared to investigator's choice, mostly pembrolizumab; these treatments currently apply to selected patients. Promoting dormancy of micrometastases, harmonizing surveillance protocols, promoting staging, identifying predictive factors, initiating controlled clinical trials, and standardizing reporting will be critical steppingstones in reaching the final frontier of curing metastatic uveal melanoma.

Prognostic Values of G-Protein Mutations in Metastatic Uveal Melanoma

Simple Summary

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. More than 90% of UMs harbor mutually exclusive activating mutations in G-proteins. The mutations are early events in UM development and considered to be driver mutations in carcinogenesis. Even after treatment of primary uveal melanoma, up to 50% of patients subsequently develop recurrence, predominantly in the liver. GNAQ mutations are not reported to be correlated to survival, while the mutations in GNA11 are reported more frequently in metastatic UM. We investigated the correlation of survival after development of metastasis (Met-to-Death) of metastatic uveal melanoma (MUM) patients with GNA11 and GNAQ mutations. We identified that MUM with mutation patterns of Q209P vs. Q209L in GNA11 and GNAQ might predict survival of MUM patients.

Abstract

Uveal melanoma is the most common primary ocular malignancy in adults, characterized by gene mutations in G protein subunit alpha q (GNAQ) and G protein subunit alpha 11 (GNA11). Although they are considered to be driver mutations, their role in MUM remains elusive. We investigated key somatic mutations of MUM and their impact on patients’ survival after development of systemic metastasis (Met-to-Death). Metastatic lesions from 87 MUM patients were analyzed by next generation sequencing (NGS). GNA11 (41/87) and GNAQ (39/87) mutations were most predominantly seen in MUM. Most GNA11 mutations were Q209L (36/41), whereas GNAQ mutations comprised Q209L (14/39) and Q209P (21/39). Epigenetic pathway mutations BAP1 (42/66), SF3B1 (11/66), FBXW7 (2/87), PBRM1 (1/66), and SETD2 (1/66) were found. No specimen had the EIF1AX mutation. Interestingly, Met-to-Death was longer in patients with GNAQ Q209P compared to GNAQ/GNA11 Q209L mutations, suggesting the difference in mutation type in GNAQ/GNA11 might determine the prognosis of MUM. Structural alterations of the GNAQ/GNA11 protein and their impact on survival of MUM patients should be further investigated.

Uveal Melanoma Metastasis

Uveal melanoma (UM) is characterized by relatively few, highly incident molecular alterations and their association with metastatic risk is deeply understood. Nevertheless, this knowledge has so far not led to innovative therapies for the successful treatment of UM metastases or for adjuvant therapy, leaving survival after diagnosis of metastatic UM almost unaltered in decades. The driver mutations of UM, mainly in the G-protein genes GNAQ and GNA11, activate the MAP-kinase pathway as well as the YAP/TAZ pathway. At present, there are no drugs that target the latter and this likely explains the failure of mitogen activated kinase kinase inhibitors. Immune checkpoint blockers, despite the game changing effect in cutaneous melanoma (CM), show only limited effects in UM probably because of the low mutational burden of 0.5 per megabase and the unavailability of antibodies targeting the main immune checkpoint active in UM. The highly pro-tumorigenic microenvironment of UM also contributes to therapy resistance. However, T-cell redirection by a soluble T-cell receptor that is fused to an anti-CD3 single-chain variable fragment, local, liver specific therapy, new immune checkpoint blockers, and YAP/TAZ specific drugs give new hope to repeating the success of innovative therapy obtained for CM.

Radiological Patterns of Uveal Melanoma Liver Metastases in Correlation to Genetic Status

This study reports the role played by the mutation status of Uveal Melanoma (UM) in relation to hepatic metastatic patterns as seen on imaging modalities. Radiological images were obtained from 123 patients treated at the Erasmus Medical Center Rotterdam or the Rotterdam Eye Hospital. Radiological images were derived from either computed tomography or magnetic resonance imaging. Hepatic metastatic patterns were classified by counting the number of metastases found in the liver. Miliary metastatic pattern (innumerable small metastases in the entire liver) was analyzed separately. Mutation status was determined in 85 patients. Median disease-free survival (DFS) and survival with metastases differed significantly between each of the metastatic patterns (respectively, p = 0.009, p < 0.001), both in favor of patients with less hepatic metastases. The mutation status of the primary tumor was not correlated with any hepatic tumor profiles (p = 0.296). Of the patients who had a solitary metastasis (n = 18), 11 originated from a primary BAP1-mutated tumors and one from a primary SF3B1-mutated tumor. Of the patients who had a miliary metastasis pattern (n = 24), 17 had a primary BAP1-mutated tumor and two had a primary SF3B1-mutated tumor. Chromosome 8p loss was significantly more in patients with more metastases (p = 0.045). Moreover, the primary UMs of patients with miliary metastases harbored more chromosome 8p and 1p loss, compared to patients with single solitary metastasis (p = 0.035 and p = 0.026, respectively). In conclusion, our study shows that there is an inverse correlation of the number of metastasis with the DFS and metastasized survival, indicating separate growth patterns. We also revealed that the number and type of metastases is irrelevant to the prognostic mutation status of the tumor, showing that both BAP1- and SF3B1-mutated UM can result in solitary and miliary metastases, indicating that other processes lay ground to the different metastatic patterns.

Molecular Insights and Emerging Strategies for Treatment of Metastatic Uveal Melanoma

Uveal melanoma (UM) is the most common intraocular cancer. In recent decades, major advances have been achieved in the diagnosis and prognosis of UM allowing for tailored treatments. However, nearly 50% of patients still develop metastatic disease with survival rates of less than 1 year. There is currently no standard of adjuvant and metastatic treatment in UM, and available therapies are ineffective resulting from cutaneous melanoma protocols. Advances and novel treatment options including liver-directed therapies, immunotherapy, and targeted-therapy have been investigated in UM-dedicated clinical trials on single compounds or combinational therapies, with promising results. Therapies aimed at prolonging or targeting metastatic tumor dormancy provided encouraging results in other cancers, and need to be explored in UM. In this review, the latest progress in the diagnosis, prognosis, and treatment of UM in adjuvant and metastatic settings are discussed. In addition, novel insights into tumor genetics, biology and immunology, and the mechanisms underlying metastatic dormancy are discussed. As evident from the numerous studies discussed in this review, the increasing knowledge of this disease and the promising results from testing of novel individualized therapies could offer future perspectives for translating in clinical use.

Molecular Genetics of Intraocular Tumors

PURPOSE

To explore the value of molecular technologies in the pathologic evaluation, diagnosis, and treatment of retinoblastoma and uveal melanoma.

METHODS

Review of the peer-reviewed literature on the molecular pathology of primary intraocular tumors.

CONCLUSION

Molecular tests are playing an increasingly important role in the diagnosis of intraocular tumors. They provide information valuable for diagnosis, prognosis, screening regimens, genetic counselling, and treatment. These technologies are becoming easier, faster, and with higher sensitivity and accuracy.

Genomic Profiling of Metastatic Uveal Melanoma and Clinical Results of a Phase I Study of the Protein Kinase C Inhibitor AEB071

Up to 50% of patients with uveal melanoma (UM) develop metastatic disease, for which there is no effective systemic treatment. This study aimed to evaluate the safety and efficacy of the orally available protein kinase C inhibitor, AEB071, in patients with metastatic UM, and to perform genomic profiling of metastatic tumor samples, with the aim to propose combination therapies. Patients with metastatic UM (n = 153) were treated with AEB071 in a phase I, single-arm study. Patients received total daily doses of AEB071 ranging from 450 to 1,400 mg. First-cycle dose-limiting toxicities were observed in 13 patients (13%). These were most commonly gastrointestinal system toxicities and were dose related, occurring at doses ≥700 mg/day. Preliminary clinical activity was observed, with 3% of patients achieving a partial response and 50% with stable disease (median duration 15 weeks). High-depth, targeted next-generation DNA sequencing was performed on 89 metastatic tumor biopsy samples. Mutations previously identified in UM were observed, including mutations in GNAQ, GNA11, BAP1, SF3B1, PLCB4, and amplification of chromosome arm 8q. GNAQ/GNA11 mutations were observed at a similar frequency (93%) as previously reported, confirming a therapeutic window for inhibition of the downstream effector PKC in metastatic UM.In conclusion, the protein kinase C inhibitor AEB071 was well tolerated, and modest clinical activity was observed in metastatic UM. The genomic findings were consistent with previous reports in primary UM. Together, our data allow envisaging combination therapies of protein kinase C inhibitors with other compounds in metastatic UM.

Secondary Somatic Mutations in G-Protein-Related Pathways and Mutation Signatures in Uveal Melanoma

BACKGROUND

Uveal melanoma (UM), a rare cancer of the eye, is characterized by initiating mutations in the genes G-protein subunit alpha Q (GNAQ), G-protein subunit alpha 11 (GNA11), cysteinyl leukotriene receptor 2 (CYSLTR2), and phospholipase C beta 4 (PLCB4) and by metastasis-promoting mutations in the genes splicing factor 3B1 (SF3B1), serine and arginine rich splicing factor 2 (SRSF2), and BRCA1-associated protein 1 (BAP1). Here, we tested the hypothesis that additional mutations, though occurring in only a few cases ("secondary drivers"), might influence tumor development.

METHODS

We analyzed all the 4125 mutations detected in exome sequencing datasets, comprising a total of 139 Ums, and tested the enrichment of secondary drivers in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways that also contained the initiating mutations. We searched for additional mutations in the putative secondary driver gene protein tyrosine kinase 2 beta (PTK2B) and we developed new mutational signatures that explain the mutational pattern observed in UM.

RESULTS

Secondary drivers were significantly enriched in KEGG pathways that also contained GNAQ and GNA11, such as the calcium-signaling pathway. Many of the secondary drivers were known cancer driver genes and were strongly associated with metastasis and survival. We identified additional mutations in PTK2B. Sparse dictionary learning allowed for the identification of mutational signatures specific for UM.

CONCLUSIONS

A considerable part of rare mutations that occur in addition to known driver mutations are likely to affect tumor development and progression.

Variability of Bad Prognosis in Uveal Melanoma

TOPIC

Survival of patients with uveal melanoma classified to have a bad prognosis.

CLINICAL RELEVANCE

To explore reasons for reported variability in survival of patients with uveal melanoma classified to have a bad prognosis.

METHODS

We searched PUBMED, MEDLINE, and EMBASE for studies reporting survival data for uveal melanoma undergoing prognostic testing with chromosome 3 status by fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), microsatellite analysis (MSA), multiplex ligation-dependent probe amplification (MLPA), single nucleotide polymorphism (SNP), gene expression profiling (GEP) class, and exon sequencing. Only studies reporting 1-year, 3-year, or 5-year survival were included in the study.

RESULTS

The initial search resulted in 49 studies. Only 12 studies met inclusion criteria. Three studies reported survival data for FISH, 1 study reported survival data for CGH, 1 study reported survival data for MSA, 3 studies reported survival data for MLPA, 3 studies reported survival data for SNP, 3 studies reported survival data for GEP, and 2 studies reported survival data for a combination of tests. No studies reported survival data for exon sequencing. Six studies reported percent free of metastatic death, 2 studies reported metastasis-free survival (MFS), 2 studies reported overall survival (OS), and 2 studies reported probability of metastasis. Metastasis-free survival (5 years) for monosomy 3 by FISH was 40% to 60%, by MLPA was 30% to 40%, by SNP was 72%, and for GEP class 2 was not reported. Overall survival (5 years) for monosomy 3 and disomy 8 tumors by MLPA and GEP class 2 were not comparable (81% and 55%, respectively).

CONCLUSIONS

Variability exists in reported survival for uveal melanoma with a bad prognosis. Several factors, including composition of study population (tumor size, exclusion of iris melanoma, duration of median follow-up), method of obtaining tumor sample, type of prognostic test, and use of variable outcome measures, can explain some of the observed differences in survival. Variations in determining the cause of death (metastatic or nonmetastatic) may be the major reason for the observed differences. Standardization of study methods and outcome measures will allow comparison of survival data derived from different prognostic tests.

In-depth proteomic profiling of the uveal melanoma secretome

Uveal melanoma (UM), the most common primary intraocular tumour in adults, is characterised by a high frequency of metastases to the liver, typically with a fatal outcome. Proteins secreted from cancer cells (‘secretome’) are biologically important molecules thought to contribute to tumour progression. We examined the UM secretome by applying a label-free nanoLCMS/MS proteomic approach to profile proteins secreted into culture media by primary UM tumours with a high− (HR; n = 11) or low− (LR; n = 4) metastatic risk, compared to normal choroidal melanocytes (NCM) from unaffected post-mortem eyes. Across the three groups, 1843 proteins were identified at a 1% false discovery rate; 758 of these by at least 3 unique peptides, and quantified. The majority (539/758, 71%) of proteins were classified as secreted either by classical (144, 19%), non-classical (43, 6%) or exosomal (352, 46%) mechanisms. Bioinformatic analyzes showed that the secretome composition reflects biological differences and similarities of the samples. Ingenuity^® pathway analysis of the secreted protein dataset identified abundant proteins involved in cell proliferation-, growth- and movement. Hepatic fibrosis/hepatic stellate cell activation and the mTORC1-S6K signalling axis were among the most differentially regulated biological processes in UM as compared with NCM. Further analysis of proteins upregulated ≥ 2 in HR-UM only, identified exosomal proteins involved in extracellular matrix remodelling and cancer cell migration/invasion; as well as classically secreted proteins, possibly representing novel biomarkers of metastatic disease. In conclusion, UM secretome analysis identifies novel proteins and pathways that may contribute to metastatic development at distant sites, particularly in the liver.

PRiMeUM: A Model for Predicting Risk of Metastasis in Uveal Melanoma

Purpose

To create an interactive web-based tool for the Prediction of Risk of Metastasis in Uveal Melanoma (PRiMeUM) that can provide a personalized risk estimate of developing metastases within 48 months of primary uveal melanoma (UM) treatment. The model utilizes routinely collected clinical and tumor characteristics on 1227 UM, with the option of including chromosome information when available.

Methods

Using a cohort of 1227 UM cases, Cox proportional hazard modeling was used to assess significant predictors of metastasis including clinical and chromosomal characteristics. A multivariate model to predict risk of metastasis was evaluated using machine learning methods including logistic regression, decision trees, survival random forest, and survival-based regression models. Based on cross-validation results, a logistic regression classifier was developed to compute an individualized risk of metastasis based on clinical and chromosomal information.

Results

The PRiMeUM model provides prognostic information for personalized risk of metastasis in UM. The accuracy of the risk prediction ranged between 80% (using chromosomal features only), 83% using clinical features only (age, sex, tumor location, and size), and 85% (clinical and chromosomal information). Kaplan-Meier analysis showed these risk scores to be highly predictive of metastasis (P < 0.0001).

Conclusions

PRiMeUM provides a tool for predicting an individual's personal risk of metastasis based on their individual and tumor characteristics. It will aid physicians with decisions concerning frequency of systemic surveillance and can be used as a criterion for entering clinical trials for adjuvant therapies.

Prognostic factors and outcomes in metastatic uveal melanoma treated with programmed cell death-1 or combined PD-1/cytotoxic T-lymphocyte antigen-4 inhibition

BACKGROUND

Uveal melanoma (UM) is an ocular malignancy with high potential for metastatic spread. In contrast to cutaneous melanoma, immunotherapy has not yet shown convincing efficacy in patients with UM. Combined immune checkpoint blockade with checkpoint programmed cell death-1 (PD-1) and checkpoint cytotoxic T-lymphocyte antigen-4 (CTLA-4) inhibition has not been systematically assessed for UM to date.

PATIENTS AND METHODS

Patients with metastatic UM treated with either PD-1 inhibitor monotherapy or combined PD-1 inhibitor and ipilimumab (an anti-CTLA-4 monoclonal antibody) were included from 20 German skin cancer centres. Records from 96 cases were analysed for treatment outcomes. Clinical and blood parameters associated with overall survival (OS) or treatment response were identified with multivariate Cox regression and binary logistic regression.

RESULTS

Eighty-six patients were treated with PD-1 inhibitors only (n = 54 for pembrolizumab, n = 32 for nivolumab) with a centrally confirmed response rate of 4.7%. Median OS was 14 months for pembrolizumab-treated and 10 months for nivolumab-treated patients (p = 0.765). Fifteen patients were treated with combined immune checkpoint blockade with partial response observed in two cases. Median OS was not reached in this group. Multivariate Cox regression identified Eastern Cooperative Oncology Group (ECOG) performance status (p = 0.002), elevated serum levels of lactate dehydrogenase (LDH) (p = 0.002) and C-reactive protein (CRP) (p = 0.001), and a relative eosinophil count (REC) <1.5% (p = 0.002) as independent risk factors for poor survival. Patients with elevated CRP and LDH and a REC <1.5% were at highest risk for disease progression and death (p = 0.001).

CONCLUSIONS

Blood markers predict survival in metastatic UM treated with immune checkpoint blockade. Normal serum levels of LDH and CRP and a high REC may help identify patients with better prognosis.

The biology of uveal melanoma

Uveal melanoma (UM), a rare cancer of the eye, is distinct from cutaneous melanoma by its etiology, the mutation frequency and profile, and its clinical behavior including resistance to targeted therapy and immune checkpoint blockers. Primary disease is efficiently controlled by surgery or radiation therapy, but about half of UMs develop distant metastasis mostly to the liver. Survival of patients with metastasis is below 1 year and has not improved in decades. Recent years have brought a deep understanding of UM biology characterized by initiating mutations in the G proteins GNAQ and GNA11. Cytogenetic alterations, in particular monosomy of chromosome 3 and amplification of the long arm of chromosome 8, and mutation of the BRCA1-associated protein 1, BAP1, a tumor suppressor gene, or the splicing factor SF3B1 determine UM metastasis. Cytogenetic and molecular profiling allow for a very precise prognostication that is still not matched by efficacious adjuvant therapies. G protein signaling has been shown to activate the YAP/TAZ pathway independent of HIPPO, and conventional signaling via the mitogen-activated kinase pathway probably also contributes to UM development and progression. Several lines of evidence indicate that inflammation and macrophages play a pro-tumor role in UM and in its hepatic metastases. UM cells benefit from the immune privilege in the eye and may adopt several mechanisms involved in this privilege for tumor escape that act even after leaving the niche. Here, we review the current knowledge of the biology of UM and discuss recent approaches to UM treatment.

Comprehensive Genetic Landscape of Uveal Melanoma by Whole-Genome Sequencing

Uveal melanoma (UM) is a rare intraocular tumor that, similar to cutaneous melanoma, originates from melanocytes. To gain insights into its genetics, we performed whole-genome sequencing at very deep coverage of tumor-control pairs in 33 samples (24 primary and 9 metastases). Genome-wide, the number of coding mutations was rather low (only 17 variants per tumor on average; range 7-28), thus radically different from cutaneous melanoma, where hundreds of exonic DNA insults are usually detected. Furthermore, no UV light-induced mutational signature was identified. Recurrent coding mutations were found in the known UM drivers GNAQ, GNA11, BAP1, EIF1AX, and SF3B1. Other genes, i.e., TP53BP1, CSMD1, TTC28, DLK2, and KTN1, were also found to harbor somatic mutations in more than one individual, possibly indicating a previously undescribed association with UM pathogenesis. De novo assembly of unmatched reads from non-coding DNA revealed peculiar copy-number variations defining specific UM subtypes, which in turn could be associated with metastatic transformation. Mutational-driven comparison with other tumor types showed that UM is very similar to pediatric tumors, characterized by very few somatic insults and, possibly, important epigenetic changes. Through the analysis of whole-genome sequencing data, our findings shed new light on the molecular genetics of uveal melanoma, delineating it as an atypical tumor of the adult for which somatic events other than mutations in exonic DNA shape its genetic landscape and define its metastatic potential.

Update on Ophthalmic Oncology 2014: Retinoblastoma and Uveal Melanoma

PURPOSE

The aim of this study was to review peer-reviewed articles on ophthalmic oncology (specifically retinoblastoma and uveal melanoma) published from January to December 2014.

DESIGN

This study is a literature review.

METHODS

The terms retinoblastoma and uveal melanoma were used in a MEDLINE literature search. Abstracts were studied, and the most relevant articles were selected for inclusion and further in-depth review.

RESULTS

In retinoblastoma, more eyes are being salvaged due to intravitreal melphalan. The year 2014 marks a deepening in our understanding of the biological basis of the disease and the cell of origin. Knowledge on the genetic underpinnings of uveal melanoma has broadened to include other pathways, interactions, and potential therapeutic targets.

CONCLUSIONS

In 2014, there were valuable advancements in our knowledge of retinoblastoma and uveal melanoma. Some of these resulted in improved patient management.

Uveal melanoma: From diagnosis to treatment and the science in between

Melanomas of the choroid, ciliary body, and iris of the eye are collectively known as uveal melanomas. These cancers represent 5% of all melanoma diagnoses in the United States, and their age-adjusted risk is 5 per 1 million population. These less frequent melanomas are dissimilar to their more common cutaneous melanoma relative, with differing risk factors, primary treatment, anatomic spread, molecular changes, and responses to systemic therapy. Once uveal melanoma becomes metastatic, therapy options are limited and are often extrapolated from cutaneous melanoma therapies despite the routine exclusion of patients with uveal melanoma from clinical trials. Clinical trials directed at uveal melanoma have been completed or are in progress, and data from these well designed investigations will help guide future directions in this orphan disease. Cancer 2016;122:2299-2312. © 2016 American Cancer Society.

Metastatic ocular melanoma to the liver exhibits infiltrative and nodular growth patterns

We examined liver specimens from 15 patients with uveal melanoma (UM) who had died of their disseminated disease. We found 2 distinct growth patterns of UM metastasis: infiltrative (n = 12) and nodular (n = 3). In the infiltrative pattern, individual UM cells with a CD133+ cancer stem cell-like phenotype were present and formed aggregates of stage I <50-μm-diameter micrometastases in the sinusoidal spaces. These micrometastases appeared to expand, destroy adjacent hepatocytes, and form stage II 51- to 500-μm-diameter and then stage III >500μm-diameter metastases, which were encapsulated by collagenized fibrous septae. In the nodular growth pattern, CD133+ melanoma cells aggregated adjacent to portal venules and subsequently appeared to grow and efface the adjacent hepatocytes to form stage II 51- to 500-μm-diameter nodules that surrounded the portal venule. These avascular nodules appeared to further expand to form stage III >500-μm-diameter nodules that exhibited vascularization with minimal fibrosis. The tumor stem cell-like phenotype seen in individual UM cells was lost as the tumors progressed. There were CD56+ natural killer cells in sinusoidal spaces and CD3+ lymphocytes in periportal areas. The nodular growth pattern showed UM cells expressing MMP9 and VEGF. UM cells in both above-described growth patterns exhibited variable BAP1 expression. We propose that changes in the liver microenvironment are related to metastatic UM growth. We hypothesize that these changes include immune regulation within the sinusoidal space for the infiltrative pattern and changes in the VEGF/PEDF ratio for the nodular pattern.

Clinical activity and safety of Pembrolizumab in Ipilimumab pre-treated patients with uveal melanoma

BACKGROUND

Untreated metastatic uveal melanoma (UM) carries a grave prognosis. Unlike cutaneous melanoma (CM), there are no established treatments known to significantly improve outcomes for a meaningful proportion of patients. Inhibition of the PD1-PDL1 axis has shown promise in the management of CM and we here report a two center experience of UM patients receiving pembrolizumab.

METHODS

To assess the efficacy and safety of pembrolizumab, we retrospectively analyzed outcome data of 25 consecutive UM patients participating in the MK3475 expanded access program (EAP) who received pembrolizumab at 2 mg/kg 3 weekly. Tumor assessment was evaluated using RECIST 1.1 and immune-related Response Criteria (irRC) by CT scanning. Toxicity was recorded utilizing Common Terminology Criteria for Adverse Events ("CTCAE") v4.03.

RESULTS

Twenty-five patients were identified receiving a median of six cycles of treatment. Two patients achieved a partial response and six patients stable disease. After a median follow-up of 225 d median progression free survival (PFS) was 91 d and overall survival (OS) was not reached. There was a significant trend for improved outcomes in patients with extrahepatic disease progression as opposed to liver only progression at the outset. Five patients experienced grade 3 or 4 adverse events (AEs); there were no treatment related deaths.

CONCLUSIONS

Pembrolizumab 2mg/kg q3w is a safe option in UM patients. Disease control rates, particularly in the subgroup of patients without progressive liver disease at the outset are promising; these results merit further investigation in clinical trials possibly incorporating liver targeted treatment modalities.

Comprehensive review of BAP1 tumor predisposition syndrome with report of two new cases

The BRCA1-associated protein-1 (BAP1) tumor predisposition syndrome (BAP1-TPDS) is a recently identified hereditary cancer syndrome. Germline mutations in this tumor suppressor gene predispose families to the development of various malignancies. The molecular functions of the gene as well as the clinical phenotype of the syndrome are still being clarified. We sought to conduct a comprehensive review of published research into BAP1-TPDS to more thoroughly delineate the clinical implications of germline BAP1 mutations. We also report two additional families with germline BAP1 mutations. Current evidence demonstrates that germline BAP1 mutations predispose families to uveal melanoma, renal cell carcinoma, malignant mesothelioma, cutaneous melanoma, and possibly to a range of other cancers as well. Some of these cancers tend to be more aggressive, have a propensity to metastasize, and onset earlier in life in patients with BAP1 mutations as compared to non-predisposed patients with equivalent cancers. Although further research is necessary, this information can aid in the management, diagnosis, and therapy of these patients and their families, and highlights the importance of genetic counseling.