Gene Expression Profiling and PRAME Status Versus Tumor-Node-Metastasis Staging for Prognostication in Uveal Melanoma

Tailoring surveillance imaging in uveal melanoma based on individual metastatic risk

OBJECTIVE

To develop surveillance programs for uveal melanoma patients, tailored to metastatic risk.

METHODS

Surveillance schedules were developed using the number needed to scan (NNS) concept, based on weighted average metastasis-free survival (MFS) rates from systematic review data of 18 prognostic groups (Disomy 3 (D3), Monosomy 3 (M3), EIF1AX-mutation, SF3B1-mutation, BAP1-mutation, high or low nBAP-1 immunohistochemistry, gene expression profiling classes (1;1A;1B;1PRAME-;1PRAME+;2;2PRAME-;2PRAME+), and V stages I-III).

RESULTS

In a typical surveillance schedule, involving biannual examinations years 1-5 and annual examinations years 6-10, the NNS varies dramatically from 1 to nearly infinity, underscoring the necessity for personalized surveillance approaches. On the basis of MFS data from 12 articles (n = 8046) and the targeted NNS level, the first surveillance examination under our model is recommended from 3 months to 5 years postdiagnosis. Specifically, the NNS 20 strategy requires an average of 10 examinations (SD 7), with D3 patients needing only two examinations (at 2- and 5-years' postdiagnosis), while those in GEP class 2PRAME+ require up to 17 examinations, scheduled between year 1 and 8. Under an NNS 20 protocol, we anticipate that 1-2% of examinations will lead to the use of effective treatments for metastatic disease, such as tebentafusp. The study presents customized surveillance schedules for all prognostic groups across various NNS levels, accompanied by a methodology for adapting surveillance to any desired NNS target.

CONCLUSION

Customizing uveal melanoma surveillance to match metastatic risks could transform current practices, ensuring more precise protocols, reducing unnecessary examinations, and directing health care resources to those in greatest need.

15-Gene Expression Profile and PRAME as Integrated Prognostic Test for Uveal Melanoma: First Report of Collaborative Ocular Oncology Group Study No. 2 (COOG2.1)

PURPOSE

Validated and accurate prognostic testing is critical for precision medicine in uveal melanoma (UM). Our aims were to (1) prospectively validate an integrated prognostic classifier combining a 15-gene expression profile (15-GEP) and PRAME RNA expression and (2) identify clinical variables that enhance the prognostic accuracy of the 15-GEP/PRAME classifier.

MATERIALS AND METHODS

This study included 1,577 patients with UM of the choroid and/or ciliary body who were enrolled in the Collaborative Ocular Oncology Group Study Number 2 (COOG2) and prospectively monitored across 26 North American centers. Test results for 15-GEP (class 1 or class 2) and PRAME expression status (negative or positive) were available for all patients. The primary end point was metastasis-free survival (MFS).

RESULTS

15-GEP was class 1 in 1,082 (68.6%) and class 2 in 495 (31.4%) patients. PRAME status was negative in 1,106 (70.1%) and positive in 471 (29.9%) patients. Five-year MFS was 95.6% (95% CI, 93.9 to 97.4) for class 1/PRAME(-), 80.6% (95% CI, 73.9 to 87.9) for class 1/PRAME(+), 58.3% (95% CI, 51.1 to 66.4) for class 2/PRAME(-), and 44.8% (95% CI, 37.9 to 52.8) for class 2/PRAME(+). By multivariable Cox proportional hazards analysis, 15-GEP was the most important independent predictor of MFS (hazard ratio [HR], 5.95 [95% CI, 4.43 to 7.99]; P < .001), followed by PRAME status (HR, 1.82 [95% CI, 1.42 to 2.33]; P < .001). The only clinical variable demonstrating additional prognostic value was tumor diameter.

CONCLUSION

In the largest prospective multicenter prognostic biomarker study performed to date in UM to our knowledge, the COOG2 study validated the superior prognostic accuracy of the integrated 15-GEP/PRAME classifier over 15-GEP alone and clinical prognostic variables. Tumor diameter was found to be the only clinical variable to provide additional prognostic information. This prognostic classifier provides an advanced resource for risk-adjusted metastatic surveillance and adjuvant trial stratification in patients with UM.

Characterization of PRAME immunohistochemistry reveals lower expression in pediatric melanoma compared to adult melanoma

Pediatric melanomas are rare tumors that have clinical and histological differences from adult melanomas. In adult melanoma, the immunohistochemical marker PRAME is increasingly employed as a diagnostic adjunct. PRAME is also under investigation as a target structure for next-generation immunotherapies including T-cell engagers. Little is known about the characteristics of PRAME expression in pediatric melanoma. In this retrospective study, samples from 25 pediatric melanomas were compared with control groups of melanomas in young adults (18-30 years; n = 32), adult melanoma (>30 years, n = 30), and benign melanocytic nevi in children (0-18 years; n = 30) with regard to the immunohistochemical expression of PRAME (diffuse PRAME expression >75%/absolute expression). Pediatric melanomas show lower diffuse PRAME expression (4%) and lower absolute PRAME expression (25%) compared to young adult melanomas (15.6%/46.8%) and adult melanomas (50%/70%). A significant age-dependent expression could be observed. An analysis of event-free survival shows no prognostic role for PRAME in pediatric melanoma and young adult melanoma, but a significant association with diffuse PRAME expression in adulthood. The age dependency of PRAME expression poses a potential pitfall in the diagnostic application of melanocytic tumors in young patients and may limit therapeutic options within this age group. The immunohistochemical expression of the tumor-associated antigen PRAME is an increasingly important diagnostic marker for melanocytic tumors and is gaining attention as a possible immunotherapeutic target in melanoma. As the available data primarily stem from adult melanoma, and given the clinical and histological distinctions in pediatric melanomas, our understanding of PRAME expression in this specific patient group remains limited. The age-dependent low PRAME expression shown here constrains the use of this marker in pediatric melanoma and may also limit the use of immunotherapeutic strategies against PRAME in young patients.

Analysis of PRAME immunocytochemistry in 109 acral malignant melanoma in situ

AIMS

Preferentially expressed antigen in melanoma (PRAME) recently is a reliable immunohistochemistry (IHC) marker for distinguishing melanoma from other lesions. However, there are few articles focused on PRAME use in acral malignant melanoma, the most common type in Asians. This study investigated PRAME IHC expression in a large series of acral malignant melanoma in situ to add to the body of clinical knowledge.

METHODS

PRAME IHC was performed in unequivocal cases of primary acral lentiginous melanoma in situ (ALMIS), subungual melanoma in situ (SMIS) and acral recurrent nevi as the control. PRAME tumour cell percentage positivity and intensity were expressed as categorised in a cumulative score by adding the quartile of positive tumour cells to intensity labelling. The final IHC expression was interpreted as negative (0-1), weak (2-3), moderate (4-5) or strong (6-7).

RESULTS

In 91 ALMIS patients, 32 cases (35.16%) were strong, 37 (40.66%) were moderate and 22 (24.18%) were weak. In 18 SMIS patients, strong positivity of PRAME was observed in 4 (22.22%) cases, moderate in 10 (55.56%) and weak in the remaining 4 (22.22%). No melanoma sample was negative for PRAME. By comparison, only 2 of the 40 acral recurrent nevi cases were positive.

CONCLUSIONS

Our study supports the ancillary value of PRAME for diagnosing ALMIS and SMIS with high sensitivity and specificity.

Heterogeneity and molecular landscape of melanoma: implications for targeted therapy

Uveal cancer (UM) offers a complex molecular landscape characterized by substantial heterogeneity, both on the genetic and epigenetic levels. This heterogeneity plays a critical position in shaping the behavior and response to therapy for this uncommon ocular malignancy. Targeted treatments with gene-specific therapeutic molecules may prove useful in overcoming radiation resistance, however, the diverse molecular makeups of UM call for a patient-specific approach in therapy procedures. We need to understand the intricate molecular landscape of UM to develop targeted treatments customized to each patient's specific genetic mutations. One of the promising approaches is using liquid biopsies, such as circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), for detecting and monitoring the disease at the early stages. These non-invasive methods can help us identify the most effective treatment strategies for each patient. Single-cellular is a brand-new analysis platform that gives treasured insights into diagnosis, prognosis, and remedy. The incorporation of this data with known clinical and genomics information will give a better understanding of the complicated molecular mechanisms that UM diseases exploit. In this review, we focused on the heterogeneity and molecular panorama of UM, and to achieve this goal, the authors conducted an exhaustive literature evaluation spanning 1998 to 2023, using keywords like "uveal melanoma, "heterogeneity". "Targeted therapies"," "CTCs," and "single-cellular analysis".

Trends in the Clinical Presentation of Uveal Melanoma During the COVID-19 Pandemic

BACKGROUND AND OBJECTIVE

The objective was to evaluate factors associated with clinical presentation of uveal melanoma (UM) during the initial two years of the coronavirus disease 2019 pandemic.

PATIENTS AND METHODS

This was a multi-site, retrospective cohort study of patients treated for uveal melanoma during the first (early) and second (late) year of the pandemic compared with the year prior (control).

RESULTS

A total of 48, 67, and 75 patients were in the control, early, and late cohorts, respectively. The early cohort had a higher frequency of large tumors (control: 29.2%, early: 40.3%, late: 29.3%; P < 0.001) at presentation. Both the early and late cohorts had higher rates of enucleation (control: 8.33%, early: 20.9%, late: 18.67%; P ≤ 0.0338) compared to the control cohort.

CONCLUSIONS

While there was an increase in large tumors along with a rise in enucleation during the first year of the pandemic, enucleation rates remained elevated even while tumor sizes normalized. [Ophthalmic Surg Lasers Imaging Retina 2024;55:278-284.].

Deferral of Treatment for Small Choroidal Melanoma and the Risk of Metastasis: An Investigation Using the Liverpool Uveal Melanoma Prognosticator Online (LUMPO)

BACKGROUND

We estimated metastatic-death risk when the treatment of small choroidal melanomas is deferred until growth is observed.

METHODS

In 24 patients with choroidal melanoma (median diameter 5.85 mm), the exponential growth rate estimated by a mixed-effects model was 4.3% per year. Using the Liverpool Uveal Melanoma Prognosticator Online v.3 (LUMPO3), we measured changes in 15-year metastatic and non-metastatic death risks according to whether the tumor is treated immediately or after observing growth 4 or 12 months later, considering age, sex, and metastasis predictors.

RESULTS

In 40-year-old females with 10 mm, disomy 3 and monosomy 3 choroidal melanomas (prevalence 16%), the 15-year absolute risks of metastatic death are 4.2% and 76.6%, respectively, increasing after a 4-month delay by 0.0% and 0.2% and by 3.0% and 2.3% with tumor growth rates of 5.0% and 20.0%, respectively. With 12-month delays, these risks increase by 0.0% and 0.5% and by 1.0% and 7.1%, respectively. Increases in metastatic-death risk are less with smaller tumors and with a higher risk of non-metastatic death.

CONCLUSIONS

Deferring treatment of choroidal melanomas until documentation of growth may delay iatrogenic visual loss by months or years and is associated with minimal increase in metastatic mortality, at least with small tumors with usual growth rates of up to 40% per year.

Liquid Biopsy Proteomics in Ophthalmology

Minimally invasive liquid biopsies from the eye capture locally enriched fluids that contain thousands of proteins from highly specialized ocular cell types, presenting a promising alternative to solid tissue biopsies. The advantages of liquid biopsies include sampling the eye without causing irreversible functional damage, potentially better reflecting tissue heterogeneity, collecting samples in an outpatient setting, monitoring therapeutic response with sequential sampling, and even allowing examination of disease mechanisms at the cell level in living humans, an approach that we refer to as TEMPO (Tracing Expression of Multiple Protein Origins). Liquid biopsy proteomics has the potential to transform molecular diagnostics and prognostics and to assess disease mechanisms and personalized therapeutic strategies in individual patients. This review addresses opportunities, challenges, and future directions of high-resolution liquid biopsy proteomics in ophthalmology, with particular emphasis on the large-scale collection of high-quality samples, cutting edge proteomics technology, and artificial intelligence-supported data analysis.

PRAME induces genomic instability in uveal melanoma

PRAME is a CUL2 ubiquitin ligase subunit that is normally expressed in the testis but becomes aberrantly overexpressed in many cancer types in association with aneuploidy and metastasis. Here, we show that PRAME is expressed predominantly in spermatogonia around the time of meiotic crossing-over in coordination with genes mediating DNA double strand break repair. Expression of PRAME in somatic cells upregulates pathways involved in meiosis, chromosome segregation and DNA repair, and it leads to increased DNA double strand breaks, telomere dysfunction and aneuploidy in neoplastic and non-neoplastic cells. This effect is mediated at least in part by ubiquitination of SMC1A and altered cohesin function. PRAME expression renders cells susceptible to inhibition of PARP1/2, suggesting increased dependence on alternative base excision repair pathways. These findings reveal a distinct oncogenic function of PRAME that can be targeted therapeutically in cancer.

Cross-Platform Identification and Validation of Uveal Melanoma Vitreous Protein Biomarkers

Purpose

The purpose of this study was to profile protein expression liquid vitreous biopsies from patients with uveal melanoma (UM) using mass spectrometry to identify prognostic biomarkers, signaling pathways, and therapeutic targets.

Methods

Vitreous biopsies were collected from two cohorts in a pilot study: comparative control eyes with epiretinal membranes (ERM; n = 3) and test eyes with UM (n = 8). Samples were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Identified proteins were compared to data from a targeted multiplex ELISA proteomics platform.

Results

A total of 69 significantly elevated proteins were detected in the UM vitreous, including LYVE-1. LC-MS/MS identified 62 significantly upregulated proteins in UM vitreous that were not previously identified by ELISA. Analysis of differential protein expression by tumor molecular classification (gene expression profiling [GEP] and preferentially expressed antigen in melanoma [PRAME]) further identified proteins that correlated with these classifications. Patients with high-risk GEP tumors displayed elevated vitreous expression of HGFR (fold-change [FC] = 2.66E + 03, P value = 0.003) and PYGL (FC = 1.02E + 04, P = 1.72E-08). Patients with PRAME positive tumors displayed elevated vitreous expression of ENPP-2 (FC = 3.21, P = 0.04), NEO1 (FC = 2.65E + 03, P = 0.002), and LRP1 (FC = 5.59E + 02, P value = 0.01). IGF regulatory effectors were highly represented (P value = 1.74E-16). Cross-platform analysis validated seven proteins identified by ELISA and LC-MS/MS.

Conclusions

Proteomic analysis of liquid biopsies may provide prognostic information supporting gene expression of tumor biopsies. The use of multiple protein detection platforms in the same patient samples increases the sensitivity of candidate biomarker detection and allows for precise characterization of the vitreous proteome.

Validation of the Prognostic Usefulness of the Gene Expression Profiling Test in Patients with Uveal Melanoma

PURPOSE

To validate the prognostic usefulness of gene expression profile (GEP) testing in patients with uveal melanoma. To determine whether combining tumor size with the GEP classification provides additional prognostic value.

DESIGN

Retrospective analysis.

PARTICIPANTS

Patients with a diagnosis of choroidal melanoma examined at Yale New Haven Hospital; University of California, San Diego; and Memorial Sloan Kettering Cancer Center.

METHODS

Patients' demographic and clinical data and tumor characteristics were collected. Univariate and multivariate Cox hazard regression analysis were used to assess the association between tumor characteristics and GEP classification with metastasis as an outcome.

MAIN OUTCOME MEASURES

Metastasis-free survival (MFS).

RESULTS

Of the 337 individuals included in the study, 87 demonstrated metastases. The mean follow-up time was 37.2 (standard deviation [SD], 40.2) months for patients with metastases and 55.0 (SD, 49.3) months for those without metastases. Tumors of larger thickness and GEP class 2 (vs. class 1) were associated significantly with increased risk of metastasis. Tumor thickness showed better prognostic usefulness than GEP classification (Wald statistic, 40.7 and 24.2, respectively). Class 2 tumors with a thickness of 7.0 mm or more were associated with increased risk of metastasis than tumors with a thickness of < 7.0 mm (hazard ratio [HR], 3.23; 95% confidence interval [CI], 1.61-6.51), whereas class 1 tumors with a thickness of 9.0 mm or more were associated with increased risk of metastasis than tumors with a thickness of < 9.0 mm (HR, 2.07; 95% CI, 0.86-4.99). No difference in MFS was found between patients with class 1A tumors compared with those with class 1B tumors (P = 0.8). Patients with class 2 tumors showed an observed 5-year MFS of 47.5% (95% CI, 36.0%-62.8%).

CONCLUSIONS

Tumor size was the most significant predictor of metastasis and provided additional prognostic value independent of GEP classification. In addition, rates of metastasis for class 2 tumors were lower than estimates reported by Castle Bioscience, and no difference in rates of metastasis were found between class 1A and 1B tumors. This indicates that tumor size should be accounted for when relying on GEP for prognostication and that patients with GEP class 1A or 1B tumors may benefit from the same metastatic surveillance protocols.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Immunohistochemical expression of PRAME is a marker of poor prognosis in uveal melanoma: A clinico-pathologic and immunohistochemical study on a series of 85 cases

PReferentially expressed Antigen in Melanoma (PRAME) is a cancer testis antigen, first isolated in tumor-reactive T-cell clones from a metastatic melanoma patient. It has been widely studied in skin pathology as an immunohistochemical marker capable of distinguishing between benign nevi and malignant melanomas. PRAME has been found to be also expressed in non-melanocytic tumors, including lung, breast, kidney and ovarian cancer. However, less is known about the diagnostic and/or prognostic role of this protein in uveal melanoma (UM); few studies have reported that PRAME expression seems to give to UM patients an additional metastatic risk beyond the other already-known prognostic parameters. In the present retrospective study, we aimed to correlate PRAME immunoreactivity to other clinico-pathologic features and follow-up data on a large series of 85 cases (45 non-metastasizing and 40 metastasizing tumors) of primary UM. A statistically significant correlation was found between PRAME expression and higher metastatic risk and lower metastasis-free survival. We propose to include PRAME in the immunohistochemical panel of UM as an easily usable marker capable of predicting higher metastatic risk and stratifying patients' outcome.

Potential diagnostic utility of PRAME and p16 immunohistochemistry in melanocytic nevi and malignant melanoma

BACKGROUND

PRAME (PReferentially expressed Antigen in MElanoma) is a tumor-associated antigen that has been studied in various cutaneous melanocytic lesions. p16, on the other hand, has been proposed to aid in distinguishing between benign and malignant melanocytic neoplasms. Studies on the diagnostic utility of PRAME and p16 in combination in differentiating nevi from melanoma are limited. We aimed to assess the diagnostic utility of PRAME and p16 in melanocytic tumors and their role in distinguishing between malignant melanomas and melanocytic nevi.

METHODS

This is a single-center retrospective cohort analysis over a 4-year period (2017-2020). We used the pathological database of malignant melanomas (77 cases) and melanocytic nevi (51 cases) specimens from patients who underwent shave/punch biopsies or surgical excisions and evaluated immunohistochemical staining percentage positivity and intensity for PRAME and p16.

RESULTS

Most malignant melanomas showed positive/diffuse PRAME expression (89.6%); on the other hand, 96.1% of nevi did not express PRAME diffusely. p16 was expressed consistently in nevi (98.0%). However, p16 expression in malignant melanoma was infrequent in our study. PRAME had a sensitivity and specificity of 89.6% and 96.1%, respectively, for melanomas versus nevi; on the other hand, p16 had a sensitivity and specificity of 98.0% and 28.6%, respectively, for nevi versus melanoma. Also, a PRAME+/p16- melanocytic lesion is unlikely to be a nevus where most nevi were PRAME-/p16+.

CONCLUSION

In conclusion, we confirm the potential utility of PRAME and p16 for distinguishing melanocytic nevi from malignant melanomas.

Diagnostic Aqueous Humor Proteome Predicts Metastatic Potential in Uveal Melanoma

Gene expression profiling (GEP) is clinically validated to stratify the risk of metastasis by assigning uveal melanoma (UM) patients to two highly prognostic molecular classes: class 1 (low metastatic risk) and class 2 (high metastatic risk). However, GEP requires intraocular tumor biopsy, which is limited by small tumor size and tumor heterogeneity; furthermore, there are small risks of retinal hemorrhage, bleeding, or tumor dissemination. Thus, ocular liquid biopsy has emerged as a less-invasive alternative. In this study, we seek to determine the aqueous humor (AH) proteome related to the advanced GEP class 2 using diagnostic AH liquid biopsy specimens. Twenty AH samples were collected from patients with UM, grouped by GEP classes. Protein expression levels of 1472 targets were analyzed, compared between GEP classes, and correlated with clinical features. Significant differentially expressed proteins (DEPs) were subjected to analysis for cellular pathway and upstream regulator identification. The results showed that 45 DEPs detected in the AH could differentiate GEP class 1 and 2 at diagnosis. IL1R and SPRY2 are potential upstream regulators for the 8/45 DEPs that contribute to metastasis-related pathways. AH liquid biopsy offers a new opportunity to determine metastatic potential for patients in the absence of tumor biopsy.

Prognostic Value of BAP1 and Preferentially Expressed Antigen in Melanoma (PRAME) Immunohistochemistry in Uveal Melanomas

Uveal melanoma (UM) is the most common primary intraocular tumor in adults, and despite excellent local control, more than 50% of patients develop and die from metastatic disease. Loss of BAP1 nuclear staining, a surrogate marker of BAP1 mutation, and preferentially expressed antigen in melanoma (PRAME) messenger RNA overexpression, as assessed using qPCR, have previously been shown to correlate with increased metastasis rate in UM. In this study, we demonstrated that UM could be successfully risk-stratified using a combination of BAP1 and PRAME immunohistochemical (IHC) stains. We retrospectively reviewed 318 UM cases with sufficient tissue and performed BAP1 and PRAME IHC to stratify them as BAP1+/PRAME- (group 1, n = 135), BAP1+/PRAME+ (group 2, n = 43), BAP1-/PRAME- (group 3, n = 94), and BAP1-/PRAME+ (group 4, n = 46). Increasing the study risk group on the basis of loss of BAP1 expression and positive PRAME staining was associated with a higher rate of metastasis and disease-specific death and lower metastasis-free survival (MFS) and disease-specific survival (DSS). Among tumors with loss of BAP1 staining, PRAME positivity was associated with shorter MFS (P = .018) and showed a trend toward shorter DSS (P = .061). Among tumors with retained BAP1 staining, PRAME positivity was associated with shorter MFS and DSS (P = .001 and P = .021, respectively). In summary, a combination of BAP1 and PRAME IHC can be used for risk stratification of UMs.

PRAME Promotes Cervical Cancer Proliferation and Migration via Wnt/β-Catenin Pathway Regulation

A significant burden is placed on the lives of females due to cervical cancer, which is currently the leading cause of cancer death among women. Preferentially expressed antigen in melanoma (PRAME) belongs to the CTA gene family and was found to be abnormally expressed among different types of cancers. Our previous research also indicated that PRAME was highly expressed in cervical cancer compared with normal tissues. However, the roles and detailed mechanisms of PRAME have not been explored in cervical cancer. In the present study, the expression of PRAME in cervical tissues and cells was detected by immunohistochemistry (IHC), qRT-PCR, and Western blotting. Additionally, CCK-8, BrdU, scratch, transwell, and flow cytometry assays were conducted to explore the function of PRAME in regulating the malignant biological behaviors of cervical cancer cells. Nude mice were used to confirm the role of PRAME in tumor growth in vivo. Furthermore, the Wnt inhibitor MSAB was used to verify the role of PRAME in regulating the Wnt/β-catenin pathway both in vitro and in vivo. The results of IHC, qRT-PCR, and Western blotting showed that PRAME was highly expressed in cervical cancer tissues and cells. PRAME knockdown attenuated cell growth, migration, and invasion; induced G0/G1 arrest; and increased cell apoptosis in C33A and SiHa cells through Wnt/β-catenin signaling regulation. However, the upregulation of PRAME exhibited the opposite effects accordingly, which could be partly reversed via MSAB treatment. The growth rate of xenograft tumors was enhanced when PRAME was overexpressed via Wnt/β-catenin signaling activation. Taken together, PRAME is associated with cervical cancer occurrence and progression mediated by Wnt/β-catenin signaling, suggesting that PRAME might be a factor in manipulating cervical carcinogenesis and a potential therapeutic target.

Choroidal Melanoma: A Mini Review

Choroidal melanoma is a rare malignant tumour, yet it is the most common primary intra-ocular neoplasm and second on the list of top ten most malignant melanoma sites in the body. Clinical presentation can be non-specific and includes photopsia, floaters, progressive visual field loss, and blurry vision. The tumour is quite often diagnosed clinically during fundus examination; however, the most valued diagnostic tests are A- and B-scan ultrasonography (US). Several factors affect prognosis, including the patient's age, tumour size, histological features, and presence of metastases. Still, with primary treatment and tight surveillance, around 50% of choroidal melanoma patients metastasise.

Diagnostic utility of immunohistochemistry in concordance with mRNA analysis of PRAME in the stratification of high-risk uveal melanoma patients

Existing clinical indicators for metastatic risk classification and patient treatment of uveal melanoma (UM) in the Asian population are limited. Preferentially expressed antigen in melanoma (PRAME) has gained attention in the prognosis of cancers and considered as a potential biomarker in many tumors including UM. Therefore, this study investigated the expression of PRAME and its association with loss of nuclear BAP1 (nBAP1) as well as its correlation with clinicopathological parameters and patient outcome. Immunohistochemical expression of PRAME and BAP1 proteins were assessed in 66 prospective cases of UM. mRNA expression level was measured by quantitative real-time PCR. Kaplan-Meier curves and Cox proportional hazard models were used to analyze the correlation of protein expression with clinicopathological parameters, metastasis-free survival and overall survival. Nuclear PRAME (nPRAME) expression and loss of nBAP1 were observed in 24 and 62% cases, respectively. PRAME mRNA expression level was found to be upregulated in 64% (7/11) of metastatic patients. mRNA and immunoexpression of nPRAME were statistically significant with many clinicopathological high-risk factors. On univariate and multivariate analyses, high mitotic activity, extraocular invasion and presence of nPRAME expression were statistically significant (p < 0.05). On Kaplan-Meier survival analysis, patients expressing PRAME had significantly reduced metastasis-free survival (MFS) and overall survival (OS). MFS and OS were also reduced in patients expressing PRAME along with loss of nBAP1. Our data show that nPRAME expression, in combination with loss of nBAP1, could be a useful predictive biomarker in the therapeutic management of UM patients at high risk.

Treatment of metastatic uveal melanoma in 2022: improved treatment regimens and improved prognosis

PURPOSE OF REVIEW

Until recently, metastatic uveal melanoma was associated with essentially uniform fatality within months. However, recent developments in screening, improved understanding of the genetic underpinnings of metastatic disease, and pivotal medication approvals have improved the disease's rate of fatality.

RECENT FINDINGS

Routine implementation of genetic testing at the time of primary tumor treatment via gene expression profiling or chromosomal analysis has identified patients who are at high risk for metastatic disease. Enhanced screening with imaging directed at the liver and lungs has allowed for identification of early disease and lower tumor burden. Significant work on improved liver directed therapy along with systemic chemotherapy and immunotherapy has improved life expectancy. The first systemic immunotherapy specifically for metastatic uveal melanoma was approved this year. This medication, tebentafusp, is likely to improve life expectancy for all patients with metastatic melanoma assuming they have appropriate human leukocyte antigen (HLA) markers. Multiple clinical trials with novel immunotherapeutic agents are promising as well.

SUMMARY

The prognosis for patients with uveal melanoma is far better than ever before because of recent developments in the understanding and treatment of metastatic disease.

Uveal melanoma patient attitudes towards prognostic testing using gene expression profiling

Aim:

This study explored uveal melanoma patient experiences and regret following molecular prognostic testing using a 15-gene expression profile (GEP) test.

Materials & methods:

A retrospective, cross-sectional survey study was conducted through an online questionnaire capturing patient-reported experiences with prognostic biopsy/molecular testing.

Results:

Of 177 respondents, 159 (90%) wanted prognostic information at diagnosis. Most 15-GEP-tested patients who shared their results (99%) reported gaining value from testing, as did patients tested with other methods. Patients who received prognostic testing experienced lower decision regret than those who opted out. Decision regret did not differ based on GEP class.

Conclusion:

Most uveal melanoma patients desire prognostic testing and gain value from the GEP, independent of a high- or low-risk result.

Uveal melanoma is a rare but aggressive eye cancer, resulting in distant metastasis in nearly 50% of patients. Molecular prognostic testing is often employed to determine who is at high or low risk of developing metastatic disease. A prognostic 15-gene expression profiling (GEP) test is commonly used throughout the USA and parts of Canada. The goal of this survey was to assess patient experiences with the 15-GEP and other prognostic methods. Of the 177 patients who participated in the survey, the majority reported that they wanted prognostic information at the time of diagnosis. Of patients who underwent 15-GEP testing, nearly all reported gaining value from their test result, regardless of their individual risk profile. This study supports prior findings using other prognostic methods that patients prefer information about their risk of metastasis and reinforces the importance of discussing prognostic testing options with newly diagnosed uveal melanoma patients.

Preferentially Expressed Antigen in Melanoma Immunohistochemistry Labeling in Uveal Melanomas

INTRODUCTION

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults, and despite treatment of the primary tumor, approximately 15%-50% of patients will develop metastatic disease. Based on gene expression profiling (GEPs), UM can be categorized as Class 1A (low metastatic risk), Class 1B (intermediate metastatic risk), or Class 2 (high metastatic risk). PReferentially expressed Antigen in MElanoma (PRAME) status is an independent prognostic UM biomarker and a potential target for immunotherapy in metastatic UM. PRAME expression status can be detected in tumors using reverse-transcription polymerase chain reaction (RT-PCR). More recently, immunohistochemistry (IHC) has been developed to detect PRAME protein expression. Here, we employed both techniques to evaluate PRAME expression in 18 UM enucleations.

METHODS

Tumor material from the 18 UM patients who underwent enucleation was collected by fine-needle aspiration before or during enucleation and sent for GEP and PRAME analysis by RT-PCR. Histologic sections from these patients were stained with an anti-PRAME monoclonal antibody. We collected patient demographics and tumor characteristics and included this with our analysis of GEP class, PRAME status by RT-PCR, and PRAME status by IHC. PRAME IHC and RT-PCR results were compared.

RESULTS

Twelve males (12/18) and 6 females (6/18) with an average age of 60.6 years underwent enucleation for UM. TNM staging of the UM diagnosed Stage I in 2 patients (2/18), Stage II in 7 patients (7/18), Stage III in 8 patients (8/18), and Stage IV in 1 (1/18). GEP was Class 1A in 6 tumors (6/18), Class 1B in 6 tumors (6/18), and Class 2 in 6 tumors (6/18). PRAME IHC showed diffusely positive labeling of all UM cells in 2/18 enucleations; negative IHC labeling of UM cells in 9/18 enucleations; and IHC labeling of subsets of UM cells in 7/18 enucleations. Eleven of the 17 UMs tested for PRAME by both RT-PCR and IHC had consistent PRAME results. In the remaining 6/17 cases tested by both modalities, PRAME results were discordant between RT-PCR and IHC.

CONCLUSIONS

We find that PRAME IHC distinguishes PRAME-positive and PRAME-negative UM tumor cells. Interestingly, IHC reveals focal PRAME expression in subsets of tumor cells consistent with tumor heterogeneity. PRAME RT-PCR and IHC provide concordant results in most of our cases. We suggest that discordance in PRAME results could arise from spatial or temporal variation in PRAME expression between tumor cells. Further studies are required to determine the prognostic implications of PRAME IHC in UM.

Preferentially Expressed Antigen in Melanoma (PRAME) and Human Malignant Melanoma: A Retrospective Study

BACKGROUND

Preferentially expressed antigen in melanoma (PRAME) is a cancer testis antigen (CTA) identified in 1997 through analysis of the specificity of tumor-reactive T-cell clones derived from a patient with metastatic cutaneous melanoma. Although at first it seemed even more specific, various studies have shown that PRAME can also be expressed in the context of atypical lesions that do not correspond solely to the definition of malignant melanoma.

METHODS

A systematic review of English articles was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

126 records were identified in the literature search, of which 9 were duplicates. After screening for eligibility and inclusion criteria, 53 publications were included.

CONCLUSIONS

The advent of a new marker such as PRAME is surely a step forward not only in the diagnostic approach, but also in the immunotherapeutic approach to MM. However, various studies have shown that PRAME can also be expressed in the context of atypical lesions apart from MM and, for this reason, the diagnostic sensitivity and specificity (hence accuracy) are clearly lower. Further studies with larger case series will be necessary to understand better what possibilities are offered in terms of diagnostic reliability by PRAME.

Integrative analysis identifies key genes related to metastasis and a robust gene-based prognostic signature in uveal melanoma

PURPOSE

Uveal melanoma (UM) is an aggressive intraocular malignancy, leading to systemic metastasis in half of the patients. However, the mechanism of the high metastatic rate remains unclear. This study aimed to identify key genes related to metastasis and construct a gene-based signature for better prognosis prediction of UM patients.

METHODS

Weighted gene co-expression network analysis (WGCNA) was used to identify the co-expression of genes primarily associated with metastasis of UM. Univariate, Lasso-penalized and multivariate Cox regression analyses were performed to establish a prognostic signature for UM patients.

RESULTS

The tan and greenyellow modules were significantly associated with the metastasis of UM patients. Significant genes related to the overall survival (OS) in these two modules were then identified. Additionally, an OS-predicting signature was established. The UM patients were divided into a low- or high-risk group. The Kaplan-Meier curve indicated that high-risk patients had poorer OS than low-risk patients. The receiver operating curve (ROC) was used to validate the stability and accuracy of the final five-gene signature. Based on the signature and clinical traits of UM patients, a nomogram was established to serve in clinical practice.

CONCLUSIONS

We identified key genes involved in the metastasis of UM. A robust five-gene-based prognostic signature was constructed and validated. In addition, the gene signature-based nomogram was created that can optimize the prognosis prediction and identify possible factors causing the poor prognosis of high-risk UM patients.

Treatment of Uveal Melanoma With Radioactive Iodine 125 Implant Compared With Proton Beam Radiotherapy

Objective

To review the current state of radiation therapy for uveal melanoma and compare particle radiation and brachytherapy.

Patients and Methods

The medical records of 156 patients treated for uveal melanoma between May 30, 2012, and March 16, 2020, were retrospectively reviewed. Treatments consisted of either radioactive iodine 125 implant (RAI) or fractionated proton radiation (proton beam therapy [PBT]). Baseline characteristics were compared using a Wilcoxon rank sum test or χ² test. Outcomes were compared using Cox proportional hazards regression models or logistic regression models.

Results

The median length of follow-up after treatment was 2.7 years (range, 0.5 to 9.0 years). Patients who underwent treatment with RAI were older (median age, 67 vs 59 years; P<.001) and had a lower tumor classification (American Joint Commission on Cancer; P=.001) compared with those who underwent PBT. There was no significant difference between RAI and PBT in the outcomes of liver metastases, death, enucleation, tearing, vision loss, retinal detachment, tumor thickness, conjunctivitis, optic neuropathy, iris neovascularization, or neovascular glaucoma (all P>.05). Patients who underwent RAI treatment had significantly higher risk of diplopia (P<.001), cataract progression (P<.001), and maculopathy (P=.03) compared with those who received PBT. Patients who underwent RAI were at higher risk of eyelash loss (P=.006) compared with the PBT group.

Conclusion

Treatment with PBT and RAI has similar efficacy; however, there are differences in the adverse outcomes associated with these 2 modalities.

Prognostic Biomarkers in Uveal Melanoma: The Status Quo, Recent Advances and Future Directions

Simple Summary

Although rare, uveal melanoma (UM) is the most common cancer that develops inside adult eyes. The prognosis is poor, since 50% of patients will develop lethal metastases in the first decade, especially to the liver. Once metastases are detected, life expectancy is limited, given that the available treatments are mostly unsuccessful. Thus, there is a need to find methods that can accurately predict UM prognosis and also effective therapeutic strategies to treat this cancer. In this manuscript, we initially compile the current knowledge on epidemiological, clinical, pathological and molecular features of UM. Then, we cover the most relevant prognostic factors currently used for the evaluation and follow-up of UM patients. Afterwards, we highlight emerging molecular markers in UM published over the last three years. Finally, we discuss the problems preventing meaningful advances in the treatment and prognostication of UM patients, as well as forecast new roadblocks and paths of UM-related research.

Abstract

Uveal melanoma (UM) is the most common malignant intraocular tumour in the adult population. It is a rare cancer with an incidence of nearly five cases per million inhabitants per year, which develops from the uncontrolled proliferation of melanocytes in the choroid (≈90%), ciliary body (≈6%) or iris (≈4%). Patients initially present either with symptoms like blurred vision or photopsia, or without symptoms, with the tumour being detected in routine eye exams. Over the course of the disease, metastases, which are initially dormant, develop in nearly 50% of patients, preferentially in the liver. Despite decades of intensive research, the only approach proven to mildly control disease spread are early treatments directed to ablate liver metastases, such as surgical excision or chemoembolization. However, most patients have a limited life expectancy once metastases are detected, since there are limited therapeutic approaches for the metastatic disease, including immunotherapy, which unlike in cutaneous melanoma, has been mostly ineffective for UM patients. Therefore, in order to offer the best care possible to these patients, there is an urgent need to find robust models that can accurately predict the prognosis of UM, as well as therapeutic strategies that effectively block and/or limit the spread of the metastatic disease. Here, we initially summarized the current knowledge about UM by compiling the most relevant epidemiological, clinical, pathological and molecular data. Then, we revisited the most important prognostic factors currently used for the evaluation and follow-up of primary UM cases. Afterwards, we addressed emerging prognostic biomarkers in UM, by comprehensively reviewing gene signatures, immunohistochemistry-based markers and proteomic markers resulting from research studies conducted over the past three years. Finally, we discussed the current hurdles in the field and anticipated the future challenges and novel avenues of research in UM.

Genetic Landscape and Emerging Therapies in Uveal Melanoma

Despite successful treatment of primary uveal melanoma, up to 50% of patients will develop systemic metastasis. Metastatic disease portends a poor outcome, and no adjuvant or metastatic therapy has been FDA approved. The genetic landscape of uveal melanoma is unique, providing prognostic and potentially therapeutic insight. In this review, we discuss our current understanding of the molecular and cytogenetic mutations in uveal melanoma, and the importance of obtaining such information. Most of our knowledge is based on primary uveal melanoma and a better understanding of the mutational landscape in metastatic uveal melanoma is needed. Clinical trials targeting certain mutations such as GNAQ/GNA11, BAP1, and SF3B1 are ongoing and promising. We also discuss the role of liquid biopsies in uveal melanoma in this review.

Five-Year Follow-up of Microincisional Vitrectomy Surgery, Endolaser Tumor Ablation, and Gene-Expression Profiling in Small Uveal Melanoma

Purpose:

This work evaluates a microincisional vitrectomy surgical (MIVS) approach to endolaser ablation of small uveal malignant melanoma by incorporating genetic tumor classification as a means to avoid radiotherapy while maintaining local tumor control without compromising visual acuity (VA).

Methods:

An institutional review board–approved, single-surgeon, retrospective analysis was conducted of a consecutive case series of all patients with tumors less than 2.5 mm in apical thickness who underwent MIVS, endolaser tumor ablation, fine-needle aspiration biopsy (FNAB), and intravitreal triamcinolone acetonide for small uveal melanoma between 2012 and 2015.

Results:

A total of 226 patients underwent FNAB from January 2012 to January 2015 for uveal melanoma. All 58 patients treated for a small uveal melanoma were included. This group of patients had a minimum follow-up of 60 months (range, 60-93 months). At initial diagnosis, subretinal fluid was present in 52 eyes (89.1%), macular edema was present in 24 eyes (41.4%), and epiretinal membrane was present in 11 eyes (20.1%). Fifty-six specimens (96.5%) received a molecular classification of either class 2 (4 of 56, 7.1%) or class 1 (52 of 56, 92.8%). Initial VA was 20/40 or better in 26 eyes (44.8%), and final VA was 20/40 or better in 48 of 58 eyes (82.8%).

Conclusions:

Endolaser tumor ablation delivered at MIVS surgery enables excellent tumor control (98.3%) and improves VA to better than 20/40 in more than 80% of treated eyes. FNAB achieves molecular classification in 96.5% of all patients undergoing treatment for small choroidal melanoma independent of tumor size.

Recent advancements in the management of retinoblastoma and uveal melanoma

Retinoblastoma in children and uveal melanoma in adults can pose a serious threat to both vision and life. For many decades, enucleation was often the only option to treat these intraocular malignancies. For retinoblastoma, intra-arterial chemotherapy is often utilized as the primary treatment at advanced academic centers and has dramatically improved local tumor control and eye salvage rates. For uveal melanoma, both plaque brachytherapy and proton beam irradiation have served as widely utilized therapies with a local failure rate of approximately 1–10%, depending on the series. Major recent advancements have allowed for a better understanding of the genomics of uveal melanoma and the impact of certain mutations on metastatic susceptibility. Gene expression profile stratifies uveal melanomas into two classes: low-risk (class 1) and high-risk (class 2). A loss-of-function mutation of BAP1 is associated with a class 2 gene expression profile and therefore confers worse prognosis due to elevated risk of metastasis. On the other hand, gain-of-function mutations of EIF1AX and SF3B1 correspond to a gene expression profile of class 1A and class 1B and confer a better prognosis. Preferentially expressed antigen in melanoma (PRAME) is an antigen that increases metastatic susceptibility when expressed in uveal melanoma cells. In addition to plaque brachytherapy and proton beam irradiation, both of which have demonstrated superb clinical outcomes, scientists are actively investigating newer therapeutic modalities as either primary therapy or adjuvant treatment, including a novel nanoparticle therapy and immunotherapy.

Oncogenic cancer/testis antigens are a hallmarker of cancer and a sensible target for cancer immunotherapy

Increasing evidence shows that numerous cancer-testis antigens (CTAs) are uniquely overexpressed in various types of cancer and most CTAs are oncogenic. Overexpression of oncogenic CTAs promotes carcinogenesis, cancer metastasis, and drug resistance. Oncogenic CTAs are generally associated with poor prognosis in cancer patients and are an important hallmark of cancer, making them a crucial target for cancer immunotherapy. CTAs-targeted antibodies, vaccines, and chimeric antigen receptor-modified T cells (CAR-T) have recently been used in cancer treatment and achieved promising outcomes in the preclinical and early clinical trials. However, the efficacy of current CTA-targeted therapeutics is either moderate or low in cancer therapy. CTA-targeted cancer immunotherapy is facing enormous challenges. Several critical scientific problems need to be resolved: (1) the antigen presentation function of MHC-I protein is usually deficient in cancer patients, so that very low amounts of intracellular CTA epitopes are presented to tumor cell membrane surface, leading to weak immune response and subsequent immunity to CTAs; (2) various immunosuppressive cells are rich in tumor tissues leading to diminished tumor immunity; (3) the tumor tissue microenvironment markedly reduces the efficacy of cancer immunotherapy. In the current review paper, the authors propose new strategies and approaches to overcome the barriers of CTAs-targeted immunotherapy and to develop novel potent immune therapeutics against cancer. Finally, we highlight that the oncogenic CTAs have high tumor specificity and immunogenicity, and are sensible targets for cancer immunotherapy. We predict that CTAs-targeted immunotherapy will bring about breakthroughs in cancer therapy in the near future.

Preferentially expressed antigen in melanoma expression in nonmelanoma skin cancers and melanocytes in surrounding skin

BACKGROUND

Immunohistochemistry for preferentially expressed antigen in melanoma (PRAME) has been studied in melanocytic lesions but not nonmelanoma skin cancers (NMSCs). This study evaluated PRAME expression in NMSCs and dermoepidermal junction (DEJ) melanocytes in the surrounding skin.

METHODS

Ninety-nine NMSCs were studied: 23 Merkel cell carcinomas (MCCs), 25 well to poorly differentiated squamous cell carcinomas (SCCs), 14 basal cell carcinomas (BCCs), five basosquamous carcinomas, four sebaceous carcinomas, ten atypical fibroxanthomas, 11 dermatofibrosarcoma protuberans, and seven leiomyosarcomas. Staining quality was considered low or high intensity. Staining quantity was reported as negative 0%, 1% to 24%, 25% to 50%, and >50%. DEJ melanocyte PRAME expression was recorded.

RESULTS

Forty-eight percent of NMSCs showed PRAME expression, mostly low intensity in fewer than 25% of cells. High-intensity expression was noted in one poorly differentiated SCC, six BCCs, and seven MCCs. Only MCCs showed expression in greater than 25% of tumor cells. Focal DEJ melanocytes expressed high-intensity PRAME in 18% of cases, most commonly SCCs (11/23).

CONCLUSIONS

PRAME is negative or expressed with low intensity in a small percentage of NMSCs, with the exception of some MCC showing high-intensity and diffuse staining. Focal DEJ melanocytes showed high-intensity PRAME reactivity in the skin surrounding some NMSCs.

Accuracy of The Cancer Genome Atlas Classification vs American Joint Committee on Cancer Classification for Prediction of Metastasis in Patients With Uveal Melanoma

Importance

The Cancer Genome Atlas (TCGA) classification is a newly emerging method for prediction of uveal melanoma (UM)-related metastasis and death. Limited information is available regarding the accuracy of the TCGA classification for prediction of metastasis in patients with UM.

Objective

To investigate the accuracy of the TCGA classification for predicting UM-related metastasis compared with the American Joint Committee on Cancer (AJCC) classification.

Design, Setting, and Participants

In this retrospective cohort study, patients with UM treated with plaque radiotherapy at a tertiary referral center from October 1, 2008, to December 31, 2018, were evaluated. All patients with tumors classified according to the American Joint Committee on Cancer Staging Manual, 8th Edition, and who completed pretreatment fine-needle aspiration biopsy sampling for genetic analysis of chromosomes 3 and 8 for TCGA classification were included. Tumors were classified into 4 categories, 17 subcategories, and 4 stages using AJCC classification and further grouped into 4 classes using TCGA classification.

Main Outcomes and Measures

Value of TCGA classification vs AJCC classification for predicting UM-related metastasis.

Results

Of 642 included patients, 331 (51.6%) were women, and the mean (SD) age was 58.0 (13.8) years. There were 642 tumors from 642 patients classified according to both AJCC and TCGA classifications. The mean (range) follow-up time for the entire cohort was 43.7 (1.4-159.2) months. At 5 years, TCGA classification showed higher value for prediction of metastasis (4 TCGA classes: Wald statistic, 94.8; hazard ratio [HR], 2.8; 95% CI, 2.3-3.5; P < .001; 4 AJCC categories: Wald statistic, 67.5; HR, 2.6; 95% CI, 2.1-3.2; P < .001; 17 AJCC subcategories: Wald statistic, 74.3; HR, 1.3; 95% CI, 1.2-1.3; P < .001; 4 AJCC stages: Wald statistic, 67.0; HR, not applicable; P < .001). After entering TCGA and AJCC classifications into a multivariate model, TCGA classification still showed higher value for prediction of metastasis (TCGA classification: Wald statistic, 61.5; HR, 2.4; 95% CI, 1.9-2.9; P < .001; AJCC classification: Wald statistic, 35.5; HR, 1.9; 95% CI, 1.5-2.4; P < .001).

Conclusions and Relevance

These results suggest that TCGA classification provides accuracy that is superior to AJCC categories, subcategories, and stages for predicting metastasis from UM. When genetic testing is available, TCGA classification can provide a more accurate way to identify patients at high risk of metastasis who might benefit from adjuvant therapy.

Parsimonious Models for Predicting Mortality from Choroidal Melanoma

Purpose

To develop parsimonious models for estimating metastasis mortality in patients with choroidal melanoma for situations where use of the Liverpool Uveal Melanoma Prognosticator Online (LUMPO) or Tumor, Node, Metastasis (TNM) staging system is not possible.

Methods

A backward-selection algorithm identified largest basal tumor diameter (LBTD) and chromosome 3 status (C3S) as the most informative predictors of metastatic death. We defined two prognostic models, based on LBTD with or without known C3S, that took into account competing risks of death from other causes by using the Aalen estimator. The bootstrap procedure was used to estimate discrimination accuracy, expressed by the C-index.

Results

The cohort was comprised of 8348 patients with choroidal melanoma, 4174 of whom had known chromosome 3 status; of the 1553 deaths that occurred among these patients, 956 were attributed to metastasis. For LBTD with or without known C3S, the metastatic-death-specific C-indices at 2, 5, and 10 years were 0.85, 0.85, and 0.84 and 0.79, 0.77, and 0.74, respectively, as compared with 0.81, 0.79, and 0.76 for Kaplan–Meier prognostication using the 8th edition of the TNM staging system.

Conclusions

We have developed parsimonious models for predicting the absolute risks of metastatic death from choroidal melanoma that take into account competing causes of death and which compare favorably with the current version of the TNM staging system. There is a need for further studies to validate the use of these models in situations where use of the TNM or LUMPO is not possible.

Uveal melanoma pathobiology: Metastasis to the liver

Uveal melanoma (UM) is a type of intraocular tumor with a propensity to disseminate to the liver. Despite the identification of the early driver mutations during the development of the pathology, the process of UM metastasis is still not fully comprehended. A better understanding of the genetic, molecular, and environmental factors participating to its spread and metastatic outgrowth could provide additional approaches for UM treatment. In this review, we will discuss the advances made towards the understanding of the pathogenesis of metastatic UM, summarize the current and prospective treatments, and introduce some of the ongoing research in this field.

The role of the cancer testis antigen PRAME in tumorigenesis and immunotherapy in human cancer

Preferentially expressed antigen in melanoma (PRAME), which belongs to the cancer/testis antigen (CTA) gene family, plays a pivotal role in multiple cellular processes and immunotherapy response in human cancers. PRAME is highly expressed in different types of cancers and is involved in cell proliferation, apoptosis, differentiation and metastasis as well as the outcomes of patients with cancer. In this review article, we discuss the potential roles and physiological functions of PRAME in various types of cancers. Moreover, this review highlights immunotherapeutic strategies that target PRAME in human malignancies. Therefore, the modulation of PRAME might be useful for the treatment of patients with cancer.

Gene Expression Profiling Prognostication of Posterior Uveal Melanoma: Does Size Matter?

PURPOSE

Investigate the influence of tumor size by American Joint Committee on Cancer (AJCC) stage, Collaborative Ocular Melanoma Study (COMS) size, tumor largest basal diameter (LBD), and tumor thickness on prognostication by gene expression profiling (GEP) class.

DESIGN

Two-center retrospective study.

PARTICIPANTS

Two hundred fifteen consecutive patients diagnosed with posterior uveal melanoma over a 5-year period who were evaluated with prognostic fine-needle aspiration biopsy at the time of primary treatment.

METHODS

Patient demographics, tumor clinical size, AJCC stage, COMS size, GEP class, presence of metastasis, and mortality data were collected. Metastasis-free-survival (MFS) was defined as time to metastasis or death from any cause. Comparisons were made using Pearson chi-square tests or Fisher exact tests for categorical factors, and t tests or Kruskal-Wallis tests for continuous measures. Cox proportional hazards models were fit to identify whether size measurements increased the prognostic discrimination index (C-statistic).

MAIN OUTCOME MEASURES

Metastasis-free-survival.

RESULTS

The average follow-up interval was 22.0 months (range, 12.0-37.0 months). Eighty-nine tumors were class 1A, 48 class 1B, and 78 class 2. Twenty-one patients developed metastatic disease detected by surveillance and confirmed by liver biopsy. Three-year MFS was 96% for class 1 and 63% for class 2. Five-year MFS was 96% for class 1 and 49% for class 2. All size measures significantly improved prognostic discrimination index by GEP class, as shown by increase in the C-statistic with addition of size variables (C-statistic 0.750 GEP alone, 0.830 GEP with AJCC [P = 0.016], 0.822 GEP with COMS [P < 0.001], 0.842 GEP with LBD [P <0.001], and 0.847 GEP with tumor thickness [P < 0.001]). Class 2 patients with metastasis had larger tumors compared with nonmetastatic class 2 tumors (AJCC class, P = 0.004; COMS class, P = 0.024; with metastasis mean thickness 6.5 mm [interquartile range (IQR), 3.8-9.5 mm]; without metastasis, 3.9 mm [SD, 3.1-6.0 mm]; P = 0.008), with metastasis mean LBD 14.9±2.8 mm, without metastasis, 12.3±2.7 mm (P < 0.001). All class 1 tumors with metastasis were large and required enucleation.

CONCLUSIONS

Incorporation of tumor size enhances the prognostic discrimination index of the GEP test in patients with posterior uveal melanoma. All size tumor parameters are equivalent in their ability to enhance GEP prognostication.

Relationship between clinical features, GEP class, and PRAME expression in uveal melanoma

BACKGROUND

Metastatic risk for uveal melanoma (UM) patients can be characterized by gene expression profiling (GEP) (Castle Biosciences, Friendswood, TX). Class 1A tumors carry low metastatic risk; class 1B tumors have intermediate risk; and class 2 tumors have high risk. Preferentially expressed antigen in melanoma (PRAME) is a tumor-associated antigen which is expressed in various neoplasms including UM. Recently, PRAME expression in uveal melanoma was first recognized to confer an additional metastatic risk beyond GEP status.

METHODS

This was a retrospective, consecutive, multicenter chart review study. All patients diagnosed with UM at two major ocular oncology centers from August 2016 to February 2018 who underwent both GEP and PRAME mRNA expression testing were included. Patient age at diagnosis, gender, and tumor variables such as thickness, largest basal diameter (LBD), tumor volume, TNM stage, and GEP class and PRAME status were extracted from the medical records. Statistical analysis was performed to analyze the association of PRAME +/- status with all clinical and molecular variables.

RESULTS

One hundred forty-eight UM patients were identified. TNM was stage I in 51 (34.5%), stage IIA in 33 (22.3%), stage IIB in 34 (23%), stage IIIA in 20 (13.5%), and stage IIIB in 10 (6.8%) patients. Fifty-five patients (37%) were PRAME-positive, a significant fraction. There was no association between higher TNM stage and positive PRAME status (p = 0.129). PRAME expression was found to be independent of gender, patient age, and tumor thickness. PRAME expression was statistically associated with LBD and tumor volume. Higher GEP class was associated with higher TNM staging (p < 0.001). Worsening GEP class was associated with PRAME+ status with 28% of GEP class 1A tumors having PRAME+ status, 29% of GEP class 1B tumors having PRAME+ status, and 56% of GEP class 2 tumors having PRAME+ status.

CONCLUSIONS

In this study cohort, PRAME+ status was significantly associated with LBD and tumor volume as well as worsening GEP class. Nearly a third of GEP class 1A tumors expressed PRAME. Given the recent published data on increased metastatic risk among patients with tumors expressing PRAME, this study suggests that a significant fraction of 1A patients may harbor an increased metastatic risk. Future large, multicenter studies with long-term follow-up will clarify this finding.