Uveal melanoma: molecular pattern, clinical features, and radiation response

Is It Possible to Preserve Vision without Compromising Metastases-Free Survival by Use of Fully Fractionated Stereotactic Radiotherapy for Posterior Choroidal Melanoma?

Introduction

Stereotactic radiotherapy (SRT) is used for choroidal melanoma (CM) abutting the optic nerve. Visual acuity (VA) deterioration to ≤6/60 is common. We report a pilot study of reduced-dose SRT using 2 Gy/day, aiming to preserve vision without compromising survival.

Method

60 Gy SRT was delivered in 30 fractions over 6 weeks. Liver metastasis surveillance was annual ultrasound. The primary endpoint was 5-year metastasis-free survival (5yMFS). Secondary endpoints were 2-year freedom from local progression (2yFFLP), VA, enucleation rate, and radiation toxicity.

Results

Twenty adults aged ≤70 years with T1-T2M0 CM without diabetes mellitus were enrolled. Median follow-up was 5.1 years. About 85% and 90% of tumours were ≤3 mm of the macula and optic disc, respectively. Median tumour height was 2.2 mm (range 1.0-4.4 mm), and median basal diameter was 8.2 mm (range: 4.3-15.0 mm). 5yMFS was 88% (95% CI: 61-97), and the 2yFFLP rate was 90% (95%: CI 66-97). There were three enucleations for disease progression. Final VA in retained eyes was ≥6/7.5 in 6 (30%), 6/9 to 6/12 in 5 (25%), 6/15 to 6/48 in 2 (10%), and ≤6/60 in 4 (20%) eyes. Retinopathy was the main cause of vision loss besides tumour progression.

Conclusion

Meaningful vision was preserved 5 years after SRT, despite high-risk tumour locations for vision loss. 2yFFLP and 5yMFS were acceptable. This dose fractionation warrants further investigation.

Comparative Single Vesicle Analysis of Aqueous Humor Extracellular Vesicles before and after Radiation in Uveal Melanoma Eyes

Small extracellular vesicles (sEVs) have been shown to promote tumorigenesis, treatment resistance, and metastasis in multiple cancer types; however, sEVs in the aqueous humor (AH) of uveal melanoma (UM) patients have never previously been profiled. In this study, we used single particle analysis to characterize sEV subpopulations in the AH of UM patients by quantifying their size, concentration, and phenotypes based on cell surface markers, specifically the tetraspanin co-expression patterns of CD9, CD63, and CD81. sEVs were analyzed from paired pre- and post-treatment (brachytherapy, a form of radiation) AH samples collected from 19 UM patients. In post-brachytherapy samples, two subpopulations, CD63/81+ and CD9/63/81+ sEVs, were significantly increased. These trends existed even when stratified by tumor location and GEP class 1 and class 2 (albeit not significant for GEP class 2). In this initial report of single vesicle profiling of sEVs in the AH of UM patients, we demonstrated that sEVs can be detected in the AH. We further identified two subpopulations that were increased post-brachytherapy, which may suggest radiation-induced release of these particles, potentially from tumor cells. Further study of the cargo carried by these sEV subpopulations may uncover important biomarkers and insights into tumorigenesis for UM.

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.

Predicted vs Observed Metastasis-Free Survival in Individuals With Uveal Melanoma

Importance

Accuracy of the predicted metastasis-free survival (MFS) by a commercially available gene expression profiling (GEP) test is not known.

Objective

To compare the predicted MFS with the observed MFS in patients in this cohort and with those in published studies (published MFS, meta-analysis).

Design, Setting, and Participants

This cohort study included consecutive patients from the University of Iowa and Cleveland Clinic who were diagnosed with uveal melanoma who underwent prognostic fine-needle aspiration biopsy at the time of primary treatment. Patients were recruited from December 2012 to December 2020. The predicted MFS for patients was extracted from the GEP report. The observed MFS was defined as time to metastasis. Cox proportional hazards models were fit to identify tumor variables impacting MFS in patients with class 2 tumors. The overall estimate of the published MFS was obtained by performing meta-analysis of data from published series. Analysis took place in August 2021.

Main Outcomes and Measures

MFS.

Results

There were 92 patients from the University of Iowa and 255 patients from the Cleveland Clinic. The mean (SD) age at diagnosis was 59.4 (13.0) years. The median (IQR) follow-up interval was 38.0 (19.0-57.0) months. The observed MFS for patients with class 2 tumor in this cohort (3 years: 67% [95% CI, 59%-77%]; 5 years: 47% [95% CI, 37%-61%]) and in published studies (3 years: 62% [95% CI, 57%-66%]; 5 years: 40% [95% CI, 34%-46%]) were better than those predicted (50% and 28% for 3 and 5 years, respectively). Within patients with class 2 tumor, those with metastasis had larger tumors compared with nonmetastatic tumors (mean largest basal diameter difference, 1.7 [95% CI, 0.5-3.0] mm; P = .01; mean thickness ratio, 1.3 [95% CI, 1.04-1.5]; P = .01, respectively). An increasing tumor size was significantly associated with increased hazard ratio (1.16 [95% CI, 1.06-1.27]; P < .001) of metastasis.

Conclusions and Relevance

These findings suggest the predicted MFS for metastatic tumors (class 2) appears to be worse than that observed here and reported by others. Incorporation of tumor size in the prediction model may enhance its accuracy. Adjuvant therapy trials may not be able to rely on predicted MFS to calculate efficacy with a high degree of confidence.

Relationship between gene expression profile class and tumor thickness regression after plaque brachytherapy for choroidal melanoma

BACKGROUND AND OBJECTIVE

To examine the relationship between gene expression profile class and tumor thickness reduction as measured by ultrasonography in response to plaque brachytherapy using a single-center, retrospective cohort study.

METHODS

A total of 15 patients with choroidal melanoma who underwent biopsy for gene expression profiling and were treated with plaque brachytherapy from a single institution from 12/8/14 through 12/19/19 were retrospectively reviewed for clinical characteristics and rate of tumor regression. Ultrasonographic B-scan tumor height was recorded just prior to plaque placement and following plaque removal in the patient's chart to assess percent reduction in tumor thickness from baseline.

RESULTS

A total of 15 patients met inclusion criteria and were analyzed in this study. Minimum follow-up was 6 months after plaque removal. The percent regression in tumor thickness from baseline as measured by ultrasonography was greater for class 2 tumors than for class 1 tumors at 12-month follow up after treatment, and this difference was statistically significant (P = 0.012). There was no statistical significance in reduction at 3 months (P = 0.46) and 9 months (P = 0.10) after plaque brachytherapy. Although not statistically significant, class 2 tumors appeared to regress more rapidly than class 1 tumors in response to radiation.

CONCLUSIONS

In this study, class 2 choroidal melanoma tumors show a more rapid anatomic response to treatment than class 1 tumors at 12 months post plaque brachytherapy.

Gene Expression Profiling in Uveal Melanoma: Five-Year Prospective Outcomes and Meta-Analysis

Introduction

The prognostic 15-gene expression profile (15-GEP) test for uveal melanoma (UM) predicts metastatic risk based on primary tumor biology. Here we report outcomes from a prospective registry of 15-GEP-tested patients, and a meta-analysis with published cohorts.

Objectives

Management and 5-year clinical outcomes following 15-GEP testing were evaluated.

Methods

Eighty-nine patients with 15-GEP results were prospectively enrolled at four centers. Physician-recommended management plans were collected, and clinical outcomes tracked every 6 months.

Results

Eighty percent of Class 1 (low-risk) patients underwent low-intensity management; all Class 2 (high-risk) patients underwent high-intensity management (p < 0.0001). Median follow-up for event-free patients was 4.9 years. Five Class 1 (10%) and 23 Class 2 (58%) tumors metastasized (p < 0.0001). Five-year Class 1 and 2 metastasis-free survival rates were 90% (81-100%) and 41% (27-62%; p < 0.0001), and melanoma-specific survival rates were 94% (87-100%) and 63% (49-82%; p = 0.0007). Class 2 was the only independent predictor of metastasis and was associated with increased risk for metastasis and mortality by meta-analysis.

Conclusions

UM patient management is guided by 15-GEP testing. Class 2 patients were managed more intensely, in accordance with an observed metastatic rate of >50%; Class 1 patients were safely spared intensive surveillance, resulting in appropriate utilization of healthcare resources.

Integrating the melanoma 31-gene expression profile test with surgical oncology practice within national guideline and staging recommendations

Aim: Define changes in clinical management resulting from the use of the prognostic 31-gene expression profile (31-GEP) test for cutaneous melanoma in a surgical oncology practice. Patients & methods: Management plans for 112 consecutively tested patients with stage I-III melanoma were evaluated for duration and number of clinical visits, blood work and imaging. Results: 31-GEP high-risk (class 2; n = 46) patients received increased management compared with low-risk (class 1; n = 66) patients. Test results were most closely associated with follow-up and imaging. Of class 1 patients, 65% received surveillance intensity within guidelines for stage I-IIA patients; 98% of class 2 patients received surveillance intensity equal to stage IIB-IV patients. Conclusion: We suggest clinical follow-up and metastatic screening be adjusted according to 31-GEP test results.

RELATIONSHIP OF CLINICAL FEATURES AND BASELINE TUMOR SIZE WITH GENE EXPRESSION PROFILE STATUS IN UVEAL MELANOMA: A Multi-institutional Study

PURPOSE

To study the relationship between gene expression profile subclass and clinical features in a multicenter cohort of patients with uveal melanoma.

METHODS

A retrospective, multicenter study was undertaken with patients entered from nine major ocular oncology centers from across the United States. Eligible patients had uveal melanoma and underwent I-125 plaque brachytherapy with concurrent tumor biopsy with gene expression profile testing between January 1, 2010, and October 28, 2014. Data were collected regarding patient demographics, baseline tumor clinical features, and gene expression profile results. Statistical analyses were performed using the Fisher's exact test, Wilcoxon rank-sum test, Kruskal-Wallis test, and proportional-odds cumulative logit modeling.

RESULTS

Inclusion criteria were met for 379 patients. Gene expression profile class divided the cohort into two main groups, Class 1 (n = 263) and Class 2 (n = 113). Class 1 tumors were further subdivided into Class 1a (n = 186) and Class 1b (n = 77). The differences between Class 1 and Class 2 tumors were similar to previous studies, except the finding of Class 2 tumors being more likely to have associated exudative retinal detachment (P < 0.001). There was no statistically significant difference between Class 1 and Class 2 tumors based on the presence of lipofuscin, drusen, or subretinal fluid. Class 1a tumor patients, compared with Class 1b, were significantly older (P = 0.034). Class 2 tumors, when compared with Class 1b, were associated with increasing patient age (P < 0.001), larger tumor height (P = 0.010), ciliary body involvement (P = 0.001), exudative retinal detachment (P = 0.024), and anterior tumor location (P < 0.001). When the tumors were grouped into Collaborative Ocular Melanoma Study size categories, increasing tumor size category was significantly associated with Class 2 status: 6% of small tumors, 32% of medium tumors, and 53% of large tumors were Class 2.

CONCLUSION

In a multi-institutional setting, we found that the only significant difference in clinical features between Class 1a and Class 1b tumors was that patients with Class 1a tumors were older at the time of diagnosis. We also found that Class 1a and Class 1b have clinical features distinct from Class 2 tumors. The distribution of the gene expression profile subclasses among the size groups was similar to reported time-to-metastasis data among the same size groupings. Our clinical findings support the current molecular classification-based survival data previously reported in uveal melanoma.

Prospective evaluation of risk-appropriate management of uveal melanoma patients informed by gene expression profiling

Aim:

The Clinical Application of DecisionDx-UM Gene Expression Assay Results study aimed to evaluate the clinical utility of the prognostic 15-gene expression profile (15-GEP) test for uveal melanoma (UM) patients in a large, prospective multicenter cohort.

Patients & methods:

Nine centers prospectively enrolled 138 UM patients clinically tested with the 15-GEP. Physician-recommended specialty referrals and metastatic surveillance regimens were collected.

Results:

A total of 93% of high-risk class 2 patients were referred to medical oncology for follow-up, compared with 51% of class 1 patients. A majority (62%) of class 2 patients were recommended overall high-intensity metastatic surveillance, while 85% of class 1 patients were recommended low-intensity metastatic surveillance.

Conclusion:

Treatment plan recommendations for UM patients are aligned with GEP-informed metastatic risk, consistent with prior studies.

CORRELATION OF GENE EXPRESSION PROFILE STATUS AND AMERICAN JOINT COMMISSION ON CANCER STAGE IN UVEAL MELANOMA

PURPOSE

To study the relationship between gene expression profile (GEP) subclass and American Joint Committee on Cancer (AJCC) stage in patients with uveal melanoma (UM).

METHODS

A retrospective, multicenter study was undertaken with patients entered from nine major ocular oncology centers from across the United States. Three hundred sixty eligible patients had UM and underwent I-125 plaque brachytherapy with concurrent tumor biopsy with GEP testing between January 1, 2010, and October 28, 2014. Patient demographics and UM features were analyzed by both GEP and AJCC status.

RESULTS

Gene expression profile class divided the cohort into three groups: Class 1a (n = 186), Class 1b (n = 77), and Class 2 (n = 113). When classified using AJCC staging criteria, we found the following: Stage I in 91 cases (25.3%), Stage IIA in 143 cases (39.7%), Stage IIB in 89 cases (24.7%), Stage IIIA in 36 cases (10%), and Stage IIIB in 1 case (0.3%). There were no Stage IV cases, as lymph node and metastatic data were not collected as a part of this study. Among Stage I tumors, both high tumor height and high largest basal diameter were associated with a higher frequency of Class 2 status (P < 0.05). As UMs progress to a larger AJCC tumor group (T1-T4), the odds ratio of having a worse prognosis based on GEP class was 1.75 (95% CI, 1.36-2.25; P < 0.001). Similarly, as UMs progress to a higher AJCC stage, the odds ratio of having a worse prognosis based on GEP class was 1.69 (95% CI, 1.36-2.10; P < 0.001).

CONCLUSION

This report details the differences in clinical features between GEP subclasses and how they are distributed among the AJCC stages. When the tumors were grouped by AJCC staging criteria, both larger AJCC tumor (T) group and worsening AJCC stage were associated with worsening predicted prognosis, based on GEP subclass.

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.

Practice Patterns for the Treatment of Uveal Melanoma with Iodine-125 Plaque Brachytherapy: Ocular Oncology Study Consortium Report 5

Background

Treatment planning for I-125 plaque therapy for uveal melanoma has advanced significantly since the Collaborative Ocular Melanoma Study trial, with more widely available image-guided planning and improved dosimetry.

Objective

We evaluated real-world practice patterns for I-125 plaque brachytherapy in the United States by studying practice patterns at centers that comprise the Ocular Oncology Study Consortium (OOSC).

Methods

The OOSC database and responses to a treatment practice survey were evaluated. The database contains treatment information from 9 institutions. Patients included in the database were treated between 2010 and 2014. The survey was conducted in 2018 and current treatment planning methods and prescriptions were queried.

Results

Examination of the OOSC database revealed that average doses to critical structures were highly consistent, with the exception of one institution. Survey responses indicated that most centers followed published guidelines regarding dose and prescription point. Dose rate ranged from 51 to 118 cGy/h. As of 2018, most institutions use pre-loaded plaques and fundus photographs and/or computed tomography or magnetic resonance imaging in planning.

Conclusions

While there were differences in dosimetric practices, overall agreement in plaque brachytherapy practices was high among OOSC institutions. Clinical margins and planning systems were similar among institutions, while prescription dose, dose rates, and dosimetry varied.

Extrascleral Tumor Extension Associated with Localized Scleral Melt following Plaque Brachytherapy for Uveal Melanoma: Clinical and Histologic Findings

BACKGROUND/AIMS

Our study aims to better characterize the clinical and histopathologic features of eyes with extrascleral uveal melanoma associated with scleral melt following brachytherapy.

METHODS

A retrospective review was performed on patients who had undergone 125I (iodine-125) brachytherapy for uveal melanoma at our institution between 1992 and 2015. Patients with postradiation scleral necrosis who required enucleation were identified, and an analysis including a review of histopathology results was performed on those cases.

RESULTS

A total of 301 patients underwent plaque brachytherapy for uveal melanoma, of whom 31 required eventual enucleation. The histologic analysis showed extraocular extension through full-thickness scleral discontinuities in 6 cases. All but 1 (5 of 6) of these eyes exhibited either mitotic figures or Ki-67 positivity. Mitotic figures were noted in 4 specimens, including 3 eyes exhibiting mitoses within or adjacent to the extrascleral portion of the tumor. Two eyes exhibiting mitoses, as well as the case with Ki-67 positivity, also had clinical evidence of tumor regrowth.

CONCLUSION

We found evidence of mitotic activity at the area of scleral discontinuity in some eyes with and in some without clinical evidence of tumor regrowth. Protruding pigmented material in areas of scleral necrosis after plaque brachytherapy may represent actively proliferating tumors even without internal evidence of tumor regrowth.

Genetic prognostication in uveal melanoma

Uveal melanoma (UM) is a rare tumour with a high propensity to metastasize. Although no effective treatment for metastases yet exists, prognostication in UM is relevant for patient counselling, planning of follow-up and stratification in clinical trials. Besides conventional clinicopathologic characteristics, genetic tumour features with prognostic significance have been identified. Non-random chromosome aberrations such as monosomy 3 and gain of chromosome 8q are strongly correlated with metastatic risk, while gain of chromosome 6p indicates a low risk. Recently, mutations in genes such as BAP1, SF3B1 and EIF1AX have been shown to be related to patient outcome. Genetics of UM is a rapidly advancing field, which not only contributes to the understanding of the pathogenesis of this cancer, but also results in further refinement of prognostication. Concomitantly, advances have been made in the use of genetic tests. New methods for genetic typing of UM have been developed. Despite the considerable progress made recently, many questions remain, such as those relating to the reliability of prognostic genetic tests, and the use of biopsied or previously irradiated tumour tissue for prognostication by genetic testing. In this article, we review genetic prognostic indicators in UM, also comparing available genetic tests, addressing the clinical application of genetic prognostication and discussing future perspectives for improving genetic prognostication in UM.

Clinical Predictors of Regression of Choroidal Melanomas after Brachytherapy: A Growth Curve Model

PURPOSE

To build multivariate models to assess correctly and efficiently the contribution of tumor characteristics on the rate of regression of choroidal melanomas after brachytherapy in a way that adjusts for confounding and takes into account variation in tumor regression patterns.

DESIGN

Modeling of longitudinal observational data.

PARTICIPANTS

Ultrasound images from 330 of 388 consecutive choroidal melanomas (87%) irradiated from 2000 through 2008 at the Helsinki University Hospital, Helsinki, Finland, a national referral center.

METHODS

Images were obtained with a 10-MHz B-scan during 3 years of follow-up. Change in tumor thickness and cross-sectional area were modeled using a polynomial growth-curve function in a nested mixed linear regression model considering regression pattern and tumor levels. Initial tumor dimensions, tumor-node-metastasis (TNM) stage, shape, ciliary body involvement, pigmentation, isotope, plaque size, detached muscles, and radiation parameters were considered as covariates.

MAIN OUTCOME MEASURES

Covariates that independently predict tumor regression.

RESULTS

Initial tumor thickness, largest basal diameter, ciliary body involvement, TNM stage, tumor shape group, break in Bruch's membrane, having muscles detached, and radiation dose to tumor base predicted faster regression, whether considering all tumors or those that regressed in a pattern compatible with exponential decay. Dark brown pigmentation was associated with slower regression. In multivariate modeling, initial tumor thickness remained the predominant and robust predictor of tumor regression (P < 0.0001). In addition, use of ruthenium isotope as opposed to iodine isotope (P = 0.018) independently contributed to faster regression of tumor thickness. For both isotopes considered alone, initial tumor thickness was the sole clinical predictor of regression (P < 0.0001).

CONCLUSIONS

Regression of choroidal melanoma after brachytherapy was associated with several clinical tumor and treatment parameters, most of which were shown to reflect initial tumor size. An independent predictor of regression of tumor thickness was the isotope used. These 2 covariates need to be adjusted for when exploring the associations with the rate of regression of histopathologic or genetic features of the tumor. Our model allows such future analyses efficiently without matching.

Gene expression profiling in uveal melanoma: technical reliability and correlation of molecular class with pathologic characteristics

BACKGROUND

A 15-gene expression profile test has been clinically validated and is widely utilized in newly diagnosed uveal melanoma (UM) patients to assess metastatic potential of the tumor. As most patients are treated with eye-sparing radiotherapy, there is limited tumor tissue available for testing, and technical reliability and success of prognostic testing are critical. This study assessed the analytical performance of the 15-gene expression test for UM and the correlation of molecular class with pathologic characteristics.

METHODS

Inter-assay, intra-assay, inter-instrument/operator, and inter-site experiments were conducted, and concordance of the 15-gene expression profile test results and associated discriminant scores for matched tumor samples were evaluated. Technical success was determined from de-identified clinical reports from January 2010 - May 2016. Pathologic characteristics of enucleated tumors were correlated with molecular class results.

RESULTS

Inter-assay concordance on 16 samples run on 3 consecutive days was 100%, and matched discriminant scores were strongly correlated (R² = 0.9944). Inter-assay concordance of 46 samples assayed within a one year period was 100%, with an R² value of 0.9747 for the discriminant scores. Intra-assay concordance of 12 samples run concurrently in duplicates was 100%; discriminant score correlation yielded an R² of 0.9934. Concordance between two sites assessing the same tumors was 100% with an R² of 0.9818 between discriminant scores. Inter-operator/instrument concordance was 96% for Class 1/2 calls and 90% for Class 1A/1B calls, and the discriminant scores had a correlation R² of 0.9636. Technical success was 96.3% on 5516 samples tested since 2010. Increased largest basal diameter and thickness were significantly associated with Class 1B and Class 2 vs. Class 1A signatures.

CONCLUSIONS

These results show that the 15-gene expression profile test for UM has robust, reproducible performance characteristics. The technical success rate during clinical testing remains as high as first reported during validation. As molecular testing becomes more prevalent for supporting precision medicine efforts, high technical success and reliability are key characteristics when testing such limited and precious samples. The performance of the 15-gene expression profile test in this study should provide confidence to physicians who use the test's molecular classification to inform patient management decisions.

Association between Tumor Regression Rate and Gene Expression Profile after Iodine 125 Plaque Radiotherapy for Uveal Melanoma

PURPOSE

Gene expression profile (GEP) testing segregates uveal melanoma (UM) into 2 main prognostic classes. It is unknown if a greater tumor regression response after iodine 125 (I¹²⁵) brachytherapy correlates with class 2 GEP status. The purpose of this study was to determine whether there is a significant relationship between the rate of UM height regression and GEP classification testing after I¹²⁵ plaque brachytherapy.

DESIGN

Multicenter, retrospective cohort study.

PARTICIPANTS

Adult UM patients treated with I¹²⁵ plaque brachytherapy who had concurrent tumor biopsy at the time of surgery with a GEP test result from January 1, 2010 through June 30, 2014.

METHODS

Baseline clinical data and GEP class assignments were obtained. The ultrasonographic tumor height was recorded at baseline and at 3, 6, 9, and 12 months and at the most recent final follow-up visits. Subanalysis of paired cases based on pretreatment ultrasound height was performed. Statistical analysis was performed using Wilcoxon rank-sum tests, the Fisher exact test, and Kaplan-Meier analysis.

MAIN OUTCOME MEASURES

Percentage change in tumor height from baseline.

RESULTS

A total of 353 patients were included in the study. Median follow-up was 2.1 years (range, 0.5-5.3 years). Gene expression profile status was class 1 in 247 tumors (70%) and class 2 in 106 tumors (30%). Increased patient age, larger tumor dimensions, and greater tumor thickness were associated with class 2 GEP status (P = 0.006, P < 0.001, and P < 0.001, respectively). The percentage reduction in tumor height from baseline was significantly greater in class 1 than class 2 tumors at 3 months (17.5% vs. 11.8%; P = 0.007) and 6 months (26.8% vs. 17.1%; P = 0.007), respectively, but there was no significant difference in reduction between class 1 and 2 tumors at 9 months (P = 0.26) and 12 months (P = 0.57) after treatment. Class 1A and 1B tumors showed similar reduction compared with class 2 tumors (P < 0.05).

CONCLUSIONS

Class 1 UM tumors tend to regress more rapidly than class 2 tumors in the first 6 months after plaque radiotherapy. Class 1A and 1B tumors regress at similar rates after plaque radiotherapy.

New concepts in the molecular understanding of uveal melanoma

PURPOSE OF REVIEW

Uveal melanoma is the most common primary intraocular malignancy, and its metastases are deadly. Significant work has been done to elucidate the molecular framework that causes uveal melanoma development and metastasis. This review is intended to highlight the most recent breakthroughs in the molecular understanding of uveal melanoma.

RECENT FINDINGS

Monosomy of chromosome 3 and class 2 gene-expression profile are well-known indicators of melanoma metastasis. However, some patients with disomy 3 and class 1 gene expression profiling (GEP) still develop metastasis. Disomy 3 tumors may be further classified based upon the presence of an SF3B1 mutation. The role of SF3B1 gene is unclear at this time but may be related to the development of late metastases among disomy 3 uveal melanoma. Class 1 GEP tumors have recently been subdivided into class 1a and class 1b, with class 1b tumors carrying a slightly higher risk of metastasis. Among patients with either class 1 or class 2 GEP, the expression of preferentially expressed antigen in melanoma (PRAME) is an independent risk factor for the development of metastasis. Mutation of GNAQ is the most commonly observed mutation in uveal melanoma, regardless of chromosome 3 status or GEP class. Inhibitors or GNAQ may be targets for therapeutic intervention in uveal melanoma. MicroRNA molecules are small noncoding RNA molecules that have been recently demonstrated to function in RNA silencing and posttranscriptional regulation of gene expression. These molecules may play a role in the development of uveal melanoma metastasis.

SUMMARY

New findings such as the presence or absence of PRAME, mutations in the SF3B1 gene and microRNA dysregulation have added new layers to our understanding of uveal melanoma. These new concepts will enhance our ability to prognosticate tumor metastasis and may provide targets for therapeutic intervention.

MYOMELANOCYTIC CHOROIDAL TUMOR: Cytopathologic Diagnosis

PURPOSE

Establishing the correct diagnosis of a growing choroidal tumor can be difficult.

METHODS

Clinical examination and ultrasound of a patient followed for what was thought to be a uveal melanoma. Fine-needle biopsy established the correct diagnosis.

RESULTS

We demonstrate that fine-needle biopsy can correctly identify a very rare tumor, a myomelanocytic neoplasm.

CONCLUSION

Myomelanocytic choroidal tumors can be diagnosed on fine-needle biopsy.

Uveal melanoma: estimating prognosis

Uveal melanoma is the most common primary malignant tumor of the eye in adults, predominantly found in Caucasians. Local tumor control of uveal melanoma is excellent, yet this malignancy is associated with relatively high mortality secondary to metastasis. Various clinical, histopathological, cytogenetic features and gene expression features help in estimating the prognosis of uveal melanoma. The clinical features associated with poor prognosis in patients with uveal melanoma include older age at presentation, male gender, larger tumor basal diameter and thickness, ciliary body location, diffuse tumor configuration, association with ocular/oculodermal melanocytosis, extraocular tumor extension, and advanced tumor staging by American Joint Committee on Cancer classification. Histopathological features suggestive of poor prognosis include epithelioid cell type, high mitotic activity, higher values of mean diameter of ten largest nucleoli, higher microvascular density, extravascular matrix patterns, tumor-infiltrating lymphocytes, tumor-infiltrating macrophages, higher expression of insulin-like growth factor-1 receptor, and higher expression of human leukocyte antigen Class I and II. Monosomy 3, 1p loss, 6q loss, and 8q and those classified as Class II by gene expression are predictive of poor prognosis of uveal melanoma. In this review, we discuss the prognostic factors of uveal melanoma. A database search was performed on PubMed, using the terms “uvea,” “iris,” “ciliary body,” “choroid,” “melanoma,” “uveal melanoma” and “prognosis,” “metastasis,” “genetic testing,” “gene expression profiling.” Relevant English language articles were extracted, reviewed, and referenced appropriately.

Uveal Melanoma Regression after Brachytherapy: Relationship with Chromosome 3 Monosomy Status

AIM

The objective was to evaluate the relationship between the regression rate of ciliary body melanoma and choroidal melanoma after brachytherapy and chromosome 3 monosomy status.

METHODS

We conducted a prospective and consecutive case series of patients who underwent biopsy and brachytherapy for ciliary/choroidal melanoma. Tumor biopsy performed at the time of radiation plaque placement was analyzed with fluorescence in situ hybridization to determine the percentage of tumor cells with chromosome 3 monosomy. The regression rate was calculated as the percent change in tumor height at months 3, 6, and 12. The relationship between regression rate and tumor location, initial tumor height, and chromosome 3 monosomy (percentage) was assessed by univariate linear regression (R version 3.1.0).

RESULTS

Of the 75 patients included in the study, 8 had ciliary body melanoma, and 67 were choroidal melanomas. The mean tumor height at the time of diagnosis was 5.2 mm (range: 1.90-13.00). The percentage composition of chromosome 3 monosomy ranged from 0-20% (n = 35) to 81-100% (n = 40). The regression of tumor height at months 3, 6, and 12 did not statistically correlate with tumor location (ciliary or choroidal), initial tumor height, or chromosome 3 monosomy (percentage).

CONCLUSION

The regression rate of choroidal melanoma following brachytherapy did not correlate with chromosome 3 monosomy status.

Disparities in Uveal Melanoma: Patient Characteristics

Uveal melanoma is the most common intraocular malignancy in adults. Despite excellent rates of local control, half of all patients with uveal melanoma ultimately go on to develop fatal metastatic disease. This review focuses on disparities and differences in the underlying characteristics of the patients, and how these patient characteristics impact the development of metastasis and subsequent patient survival. Specifically, we detail disparities in epidemiology and risk factors as they relate to the development of primary uveal melanoma, to the development of metastasis, and to patient survival following metastasis.

Tumor-height regression rate after brachytherapy between choroidal melanoma gene expression profile classes: effect of controlling for tumor height

PURPOSE

To evaluate the relationship between choroidal melanoma regression rate and its gene expression profile class after iodine-125 brachytherapy at 3 and 6 months, controlling for baseline tumor height.

METHODS

Patients from October 2012 to January 2015 at a single Ophthalmic Oncology Center who had undergone iodine-125 brachytherapy for the treatment of choroidal melanoma and who had a gene expression profile test result obtained from intraoperative fine-needle aspiration biopsy at the time of plaque surgery were retrospectively reviewed. Baseline patient and tumor characteristics were obtained, including tumor height and gene expression profile test result. Tumor height at 3 and 6 months following treatment was obtained. Regression rate was analyzed with two-way analysis of variance to class type and baseline pre-operative tumor height. Class 2 patients were matched to class 1 patients by tumor height and resulting distributions of paired regression rate differences were compared.

RESULTS

A total of 114 patients were studied. When preoperative tumor height was controlled for in the comparative analysis, neither group of patients at 3 or 6 months had a significant dependency between gene expression profile class and tumor regression rate. Additionally, class 1 and class 2 patients matched for pre-operative tumor height did not express different regression rates.

CONCLUSIONS

Our study adds to a growing body of evidence that tumor regression rate does not necessarily depend on gene expression profile class type in choroidal melanoma after brachytherapy at 3 and 6 months when controlling for baseline tumor height.

Independent Prognostic Significance of Gene Expression Profile Class and Largest Basal Diameter of Posterior Uveal Melanomas

PURPOSE

To determine whether any conventional clinical prognostic factors for metastasis from uveal melanoma retain prognostic significance in multivariate models incorporating gene expression profile (GEP) class of the tumor cells.

DESIGN

Prospective, interventional case series with a prognostic model.

METHODS

Single-institution study of GEP testing and other conventional prognostic factors for metastasis and metastatic death in 299 patients with posterior uveal melanoma evaluated by fine-needle aspiration biopsy (FNAB) at the time of or shortly prior to initial treatment. Univariate prognostic significance of all evaluated potential prognostic variables (patient age, largest linear basal diameter of tumor [LBD], tumor thickness, intraocular location of tumor, melanoma cytomorphologic subtype, and GEP class) was performed by comparison of Kaplan-Meier event rate curves and univariate Cox proportional hazards modeling. Multivariate prognostic significance of combinations of significant prognostic factors identified by univariate analysis was performed using step-up and step-down Cox proportional hazards modeling.

RESULTS

GEP class was the strongest prognostic factor for metastatic death in this series. However, tumor LBD, tumor thickness, and intraocular tumor location also proved to be significant individual prognostic factors in this study. On multivariate analysis, a 2-term model that incorporated GEP class and largest basal diameter was associated with strong independent significance of each of the factors.

CONCLUSION

Although GEP test is the most robust prognostic indicator in uveal melanoma and early studies of mostly larger tumors found that no clinicopathologic factors had significant prognostic value independent of GEP, our single-center study, which included a substantial proportion of smaller tumors, showed that both GEP and LBD of the tumor are independent prognostic factors for metastasis and metastatic death in multivariate analysis.

Gene expression profiling and regression rate of irradiated uveal melanomas

BACKGROUND AND OBJECTIVE

Uveal melanoma is the most common primary intraocular cancer; however, the molecular features that predict response to therapy are poorly understood. Our objective was to determine whether gene expression profiling (GEP) is associated with rate of tumor regression after I-125 plaque brachytherapy for uveal melanoma.

PATIENTS AND METHODS

Retrospective review of 138 patients with posterior uveal melanoma treated with I-125 plaque brachytherapy in which GEP class and 3-month post-radiation ultrasonographic tumor thickness data were available. Statistical analysis was performed using t test and Fisher's exact test.

RESULTS

GEP class assignment was class 1 in 83 (60.1%) and class 2 in 55 (39.9%) patients. Mean patient age was 60.9 years for class 1 and 68.1 years for class 2 tumors (P = .002). Mean initial tumor diameter was 13.0 mm for class 1 and 14.1 mm for class 2 tumors (P = .02). Mean initial tumor thickness was 5.2 mm for class 1 and 6.1 mm for class 2 tumors (P = .047). Three months after I-125 plaque radiotherapy, mean reduction in tumor thickness was 26.5% for class 1 and 16.7% for class 2 tumors (P = .03).

CONCLUSION

Class 1 uveal melanoma tumors exhibit more rapid early tumor regression than class 2 tumors after I-125 plaque radiotherapy.

Regression rate of posterior uveal melanomas following iodine-125 plaque radiotherapy

AIM

To characterize the regression rate of posterior uveal melanoma following radioactive iodine-125 (I-125) plaque.

MATERIALS AND METHODS

We retrospectively analyzed 95 patients with posterior uveal melanoma who were treated with only radioactive I-125 plaque and had more than 3 years follow-up. All patients were treated with plaque radiotherapy using tumor dose of 85 Gy at the tumor apex, following COMS protocol. Regression rate was assessed with standardized A-scan ultrasonography. Associations with tumor regression were evaluated by means of mixed linear regression modeling.

RESULTS

Mean decrease in the tumor thickness (% original thickness) at 12, 24, and 36 months after radiotherapy for melanomas < 3 mm in thickness was 29%, 38%, and 45%, for melanoma 3-8 mm in thickness was 32%, 44%, and 59%, and for melanoma more than 8 mm in thickness was 52%, 62%, and 68%, respectively. With a doubling of follow-up time (0.5-1 year, or 1-2 years of follow-up from treatment), tumors < 3 mm in thickness at treatment showed a 0.5 mm decrease in tumor thickness, whereas melanomas 3-8 mm showed a 1 mm decrease, and melanomas >8 mm showed a 1.7 mm decrease. Uveal melanomas that developed systemic metastasis showed an additional 0.4 mm decrease with a doubling of follow-up time from treatment, compared with those that did not develop metastasis (P = 0.050).

CONCLUSIONS

Posterior uveal melanomas with higher initial thickness show steeper and more reduction in tumor thickness following radioactive I-125 plaque. After the initial phases, the regression curve became similar for tumors with different thicknesses.

Does choroidal melanoma regression correlate with chromosome 3 loss after ruthenium brachytherapy?

AIM

To determine the reduction of choroidal melanoma thickness 6 months after ruthenium 106-brachytherapy according to chromosome 3 status, which correlates strongly with metastatic death.

METHODS

Transscleral fine needle aspiration biopsy was performed prior to the insertion of a radioactive plaque if the tumour was deemed sufficiently thick and anterior for such a procedure. Transretinal biopsy with a 25-gauge vitreous cutter was performed for thin and posterior tumour within a month of plaque removal. The chromosome 3 status was determined by fluorescence in situ hybridisation from 2002 until 2006, and by either multiplex ligation-dependent probe amplification and/or microsatellite analysis after this period until the end of the study. The choroidal melanoma dimensions were obtained from outpatient visits.

RESULTS

149 eyes from 149 patients were included. The mean age was 60.8 years. 84 eyes (56.4%) had disomy 3 and 65 eyes (43.6%) monosomy 3. The median pretreatment tumour thickness was 3.0 mm in disomy 3 and 4.1 mm in monosomy 3 tumours (p=0.018). The follow-up duration medians were 6.3 months for disomy 3 and 6.4 months for monosomy 3 tumours (p=0.68). The rates of thickness reduction were 6.7% and 7.0% per month, respectively (p=0.59). Thickness reduction exceeding 50% occurred in 32 (38.1%) disomy 3 and 24 (36.9%) monosomy 3 tumours.

CONCLUSIONS

The rate of choroidal melanoma regression after ruthenium-106 brachytherapy does not appear to correlate with chromosome 3 loss, suggesting that tumour thickness reduction 6 months after treatment is unlikely to predict survival.