Gene expression profiling and regression rate of irradiated uveal melanomas

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.

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.

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.

Regression patterns of uveal melanoma after iodine-125 plaque brachytherapy

Background

Tumor regression of uveal melanomas (UMs) after radiotherapy has been reported as a valuable prognostic factor for metastasis and metastatic death. But its effect on prognosis is questionable. The purpose of this study was to summarize the regression features of uveal melanoma after iodine-125 plaque brachytherapy and the relationship with prognosis.

Methods

Adult uveal melanoma patients who only received iodine-125 plaque brachytherapy between December 2009 and March 2018 at the Beijing Tongren Hospital, Capital Medical University were enrolled in this study. The regression rate was calculated as the percent change in tumor height, and each eye was classified for four main regression patterns: Decrease (D), Stable (S), Others (O), and Increase (I), according to the trend of height change. Statistical analysis was performed using one-way ANOVA and chi-square test, univariate and multivariate logistic regression, and Kaplan-Meier analysis.

Results

A total of 139 patients was included in the study. The median follow-up was 35 months. Regression patterns status was pattern D in 65 tumors (46.8%), pattern S in 50 tumors (36.0%), pattern O in 6 tumors (4.3%), and pattern I in 18 tumors (12.9%). Reductions of tumor mean height for each follow-up visit were 5.26% (3 months), 10.66% (6 months), 9.37% (12 months), and 14.68% (18 months). A comparison (D vs. S vs. O vs. I) revealed the preoperative height of pattern I was significantly lower than the pattern D, S and O (mean: 7.24 vs. 7.30 vs. 6.77 vs. 5.09 mm, respectively; P = 0.037). LBD (largest basal diameter) was strongly associated with the metastasis (P = 0.03). However, an association between the tumor regression and subsequent melanoma-related metastasis and mortality could not be confirmed (P = 0.66 and P = 0.27, respectively). The tumor regression rate increased with increasing tumor height (P = 0.04) and decreased with increasing of LBD (P = 0.01).

Conclusion

Our study showed a lack of association between the prognosis and the regression of uveal melanomas following I-125 plaque radiotherapy. The LBD and original height of the tumor have predictive value in tumor regression rate, and LBD was positively associated with metastasis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01898-3.

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.

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.

Recent advancements in the management of retinoblastoma and uveal melanoma

Retinoblastoma and uveal melanoma are the most common intraocular malignancies observed in pediatric and adult populations, respectively. For retinoblastoma, intra-arterial chemotherapy has dramatically improved treatment outcomes and eye salvage rates compared with traditional salvage rates of systemic chemotherapy and external beam radiation therapy. Intravitreal injections of chemotherapy have also demonstrated excellent efficacy for vitreous seeds. Uveal melanoma, on the other hand, is treated predominantly with iodine-125 plaque brachytherapy or with proton beam therapy. Major strides in uveal melanoma genomics have been made since the early 2000s, allowing ocular oncologists to better understand the metastatic risks of the tumor on the basis of specific genetic signatures. Loss-of-function mutations of the BAP1 gene are associated with the highest metastatic risk, whereas gain-of-function mutations of SF3B1 and EIF1AX often confer a better prognosis. Expression of a cancer-testis antigen called PRAME (preferentially expressed antigen in melanoma) has been shown to increase metastatic risks in both low-risk and high-risk melanomas. New therapeutic approaches, including molecular therapies and nanoparticle phototherapy, are currently being investigated as alternative treatment modalities for uveal melanoma.

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.

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.

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.

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.