CHOROIDAL NEVUS TRANSFORMATION INTO MELANOMA PER MILLIMETER INCREMENT IN THICKNESS USING MULTIMODAL IMAGING IN 2355 CASES: The 2019 Wendell L. Hughes Lecture

Long Term Follow-Up Observation in Small Choroidal Melanocytic Tumors

BACKGROUND

The purpose of this study is to analyze the long-term evolution of patients with small choroidal melanocytic tumors (SCMTs) undergoing observation, and to assess their rate of transformation into melanomas and survival.

METHODS

A retrospective single-cohort study of patients with SCMTs (1-3 mm in height and 5-10 mm in base) diagnosed from January 1992 to February 2023 was carried out, with observation as the initial treatment. The main criterion for a transformation into melanoma is considered to be an increase in size of more than 1 mm in height and/or more than 1 mm in base measured on an ultrasound/retinography, recorded in two consecutive visits separated by one to three months.

RESULTS

243 patients were included with a mean age of 65.3 years and a mean follow-up of 7.9 years (6 months-27.9 years); 27 patients showed tumor growth. The probabilities of growth at 5, 10, and 15 years are 10%, 14%, and 17%, respectively. Regarding survival, 22 patients died and only 3 deaths were due to melanoma metastasis. Survival rates at 5 and 10 years are 99% and 97%.

CONCLUSIONS

Observation is a viable therapeutic option for SCMTs, avoiding the side effects of treatment, considering the majority of these tumors do not progress to melanoma. With close monitoring, patients can be treated promptly upon detecting a transformation. Additionally, the findings confirm that small melanocytic tumors can lead to metastatic disease, albeit at a low rate.

Using Deep Learning to Distinguish Highly Malignant Uveal Melanoma from Benign Choroidal Nevi

Background: This study aimed to evaluate the potential of human-machine interaction (HMI) in a deep learning software for discerning the malignancy of choroidal melanocytic lesions based on fundus photographs. Methods: The study enrolled individuals diagnosed with a choroidal melanocytic lesion at a tertiary clinic between 2011 and 2023, resulting in a cohort of 762 eligible cases. A deep learning-based assistant integrated into the software underwent training using a dataset comprising 762 color fundus photographs (CFPs) of choroidal lesions captured by various fundus cameras. The dataset was categorized into benign nevi, untreated choroidal melanomas, and irradiated choroidal melanomas. The reference standard for evaluation was established by retinal specialists using multimodal imaging. Trinary and binary models were trained, and their classification performance was evaluated on a test set consisting of 100 independent images. The discriminative performance of deep learning models was evaluated based on accuracy, recall, and specificity. Results: The final accuracy rates on the independent test set for multi-class and binary (benign vs. malignant) classification were 84.8% and 90.9%, respectively. Recall and specificity ranged from 0.85 to 0.90 and 0.91 to 0.92, respectively. The mean area under the curve (AUC) values were 0.96 and 0.99, respectively. Optimal discriminative performance was observed in binary classification with the incorporation of a single imaging modality, achieving an accuracy of 95.8%. Conclusions: The deep learning models demonstrated commendable performance in distinguishing the malignancy of choroidal lesions. The software exhibits promise for resource-efficient and cost-effective pre-stratification.

Intralesional Vessel Diameter Measured by Optical Coherence Tomography Angiography Could Improve the Differential Diagnosis of Small Melanocytic Choroidal Lesions

In this study, we aimed to identify the features of indeterminate choroidal melanocytic lesions visualized on optical coherence tomography angiography (OCTA) and to identify the predictors of growth. We retrospectively evaluated 86 patients with indeterminate lesions treated at our centre from 2016 to 2021. Clinical management involved active surveillance followed by brachytherapy if growth was detected. The lesions were classified into two groups according to whether they grew (small melanomas) or remained stable (choroidal nevi). Growth was detected in 19 (22.1%) lesions. All patients underwent OCTA at baseline. These images were compared to identify the possible predictors of growth. Significant between-group differences were observed in thickness (p = 0.00), greatest basal diameter (p = 0.00), number of risk factors (p = 0.00), symptoms (p = 0.001; relative risk [RR]: 4.3), orange pigment (p = 0.00; RR: 6.02), and ultrasonographic hollowness (Kappa sign); p = 0.000; RR: 5.3). The melanomas had significantly more vessels with a diameter ≥ 76.3 µm (p = 0.02; RR: 2.46). The time to growth in these lesions was significantly shorter (p = 0.05) than in lesions with smaller vessels. These findings show that vessel diameter quantified by OCTA can help differentiate between choroidal nevi and small melanomas, when considered together with clinical risk factors.

Choroidal nevus through a broader vision: Retinal imaging acquisition captured with Broad Line Fundus Imaging technology

OBJECTIVE

To describe the peculiarities in imaging acquisition of fourteen patients with choroidal nevus using the Broad Line Fundus Imaging (BLFI) technology.

METHODS

Single-center, retrospective, cross-sectional analysis.

RESULTS

All images were acquired using the BLFI technology. We have found that choroidal nevus is undetectable in the blue channel (BC) (435-500 nm) and the green channel (GC) (500-585 nm). The only visible changes are related to the drusen, which appeared in BC and GC as light focal dots, correlated to the yellowish foci in the true-color image. On the red channel (RC) (585-640 nm), all lesions revealed the same pattern: a well-defined dark spot, with enhanced contrast, allowing the better visualization, measuring, and characterization of the nevus when compared with the other color channels, including the true-color imaging.

CONCLUSION

BLFI application in choroidal nevus might be helpful at presentation, refining the diagnostic reliability, and monitoring, as it allows for better detection of alterations in the lesions. The peculiarities of the choroidal nevus are better assessed when using the RC due to its longer wavelength and deeper penetration in the retina and choroid.

Understanding choroidal nevus risk factors for transformation into melanoma

A choroidal nevus is a common intraocular tumor in the United States, found in approximately 5% of Caucasian adults. The three main risks of melanocytic choroidal nevus include vision loss from a subfoveal nevus, development of subretinal fluid, and transformation of nevus into melanoma, a malignant counterpart. We explore clinical risk factors that predict benign melanocytic choroidal nevus transformation into a malignant choroidal melanoma. Based on a large analysis of 2,355 cases that were monitored longitudinally using multimodal imaging, the most recent list of clinical features includes tumor Thickness greater than 2 mm on ultrasonography, subretinal Fluid on optical coherence tomography, Symptomatic vision loss 20/50 or worse, Orange pigment on fundus autofluorescence, Melanoma hollow on ultrasonography, and DIaMeter greater than 5 mm on fundus photography. These factors are remembered with a mnemonic of the capital letters TFSOM-DIM for "To Find Small Ocular Melanoma Doing Imaging." Analysis of these factors demonstrated a Kaplan-Meier mean five-year risk of 1% with no risk factors, 11% with any one factor, 22% with any two factors, 34% with any three factors, 51% with any four factors, and 55% with any five factors. There was no patient with six risk factors. Of those with combinations of four risk factors, six of 15 combinations yielded a 70%-100% rate of transformation; of those with combinations of five risk factors, two of five combinations yielded a 70%-100% rate of transformation. Choroidal nevus carries a risk for evolving into melanoma, and understanding of clinical and imaging features predictive of this outcome is highly important.

Growth rate of indeterminate choroidal lesions prior to melanoma diagnosis

PURPOSE

Small choroidal melanocytic lesions have a low rate of metastasis and can be reasonably managed with surveillance until they demonstrate evidence of growth or clinical risk factors for melanoma. However, even choroidal nevi are not stationary, with many exhibiting slow growth over time. We sought to quantify the growth rates of indeterminate choroidal lesions that were initially observed prior to a clinical diagnosis of melanoma.

METHODS

A single-center retrospective study was performed of patients diagnosed with choroidal melanoma based upon clinical characteristics who were initially followed for indeterminate lesions over at least 6 months. Subjects were included if they had a minimum of two B-scan ultrasound measurements prior to the visit at which melanoma was diagnosed. Demographic and tumor characteristics were collected from the medical record. Growth rates were calculated as the change in lesion thickness in mm per month and were recorded at 6-month intervals; ultrasound measurements less than 1 month apart were excluded. The characteristics of indeterminate lesions with faster versus slower growth rates prior to melanoma diagnosis were compared.

RESULTS

Fifty-four patients met inclusion criteria. The mean age at melanoma diagnosis was 67.4 years, and 53.7% were female. Subjects had a median of four B-scan ultrasound measurements prior to melanoma diagnosis (range 2-19) and were followed for a median of 40.6 months (range 9.9-138.0 months). The mean lesion thickness was 1.4 mm (range 0.5-2.2 mm) at presentation, and increased to 2.3 mm (range 1.5-5.7 mm) at melanoma diagnosis. The mean growth rate did not exceed 0.021 mm/month (95% CI: 0.004-0.039; equivalent to 0.25 mm/year) for indeterminate lesions, but increased to 0.057 mm/month (95% CI: 0.043-0.071 mm/month; equivalent to 0.68 mm/year) at the time of melanoma diagnosis. Rapidly growing lesions had a greater tumor thickness and shorter duration of observation at the time of melanoma diagnosis.

CONCLUSION

For most indeterminate choroidal lesions eventually diagnosed as melanoma, the lesion thickness was relatively stable for a period of time, then rose significantly between the penultimate visit and the final visit. These findings confirm the recommendation for continued monitoring of suspicious choroidal lesions, as the growth rate may accelerate just prior to melanoma diagnosis. Lesions with a mean growth rate of up to 0.25 mm/year were observed, whereas lesions clinically determined to have transformed into melanoma demonstrated a mean growth rate of 0.68 mm/year. These values provide a baseline for future studies and potential therapies directed at stabilizing or reducing the growth of indeterminate choroidal lesions or small choroidal melanomas. Limitations of this study include its retrospective nature and reliance on clinical diagnostic criteria.

Choroidal biopsies; a review and optimised approach

The majority of choroidal tumours are diagnosed accurately with clinical examination and the additional data obtained from non-invasive imaging techniques. Choroidal biopsies may be undertaken for diagnostic clarity in cases such as small melanocytic or indeterminate lesions, identifying the primary tumour in the case of choroidal metastases or the subclassification of rarer conditions such as uveal lymphoma. There is however an increasing use of biopsy techniques for prognostication in uveal melanoma. This review explores the main indications and surgical techniques for tumour acquisition, and the optimised approach utilised by the current authors to improve successful yield for histological and genetic analysis.

Imaging of Uveal Melanoma—Current Standard and Methods in Development

Simple Summary

Uveal melanoma is the most prevalent intraocular tumor in adults, derived from melanocytes; the liver is the most common site of its metastases. Due to troublesome tumor localization, different imaging techniques are utilized in diagnostics, i.e., fundus imaging (FI), ultrasonography (US), optical coherence tomography (OCT), single-photon emission computed tomography (SPECT), positron emission tomography/computed tomography (PET/CT), magnetic resonance imaging (MRI), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), or fundus autofluorescence (FAF). Specialists eagerly use these techniques, but sometimes the precision and quality of the obtained images are imperfect, raising diagnostic doubts and prompting the search for new ones. In addition to analyzing the currently utilized methods, this review also introduces experimental techniques that may be adapted to clinical practice in the future. Moreover, we raise the topic and present a perspective for personalized medicine in uveal melanoma treatment.

Abstract

Uveal melanoma is the most common primary intraocular malignancy in adults, characterized by an insidious onset and poor prognosis strongly associated with tumor size and the presence of distant metastases, most commonly in the liver. Contrary to most tumor identification, a biopsy followed by a pathological exam is used only in certain cases. Therefore, an early and noninvasive diagnosis is essential to enhance patients’ chances for early treatment. We reviewed imaging modalities currently used in the diagnostics of uveal melanoma, including fundus imaging, ultrasonography (US), optical coherence tomography (OCT), single-photon emission computed tomography (SPECT), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), fundus autofluorescence (FAF), as well as positron emission tomography/computed tomography (PET/CT) or magnetic resonance imaging (MRI). The principle of imaging techniques is briefly explained, along with their role in the diagnostic process and a summary of their advantages and limitations. Further, the experimental data and the advancements in imaging modalities are explained. We describe UM imaging innovations, show their current usage and development, and explain the possibilities of utilizing such modalities to diagnose uveal melanoma in the future.

Small Choroidal Melanoma: Correlation of Growth Rate with Pathology

Purpose

The aim of the study was to evaluate equivalence of growth rate and pathologic confirmation in small choroidal melanoma (SCM).

Design

This study is a case series.

Subjects Participants and Controls

A total of 61 patients with a choroidal melanocytic tumor of size 5.0-16.0 mm in the largest basal diameter and 1.0-2.5 mm in thickness were classified into the pathology-confirmed group (n = 19), growth-confirmed group (n = 30), and with combined observations (n = 12).

Methods

Distribution of clinical variables (age, gender, laterality, tumor dimensions, tumor location, and presence of orange pigment, subretinal fluid, drusen, and retinal pigment epithelial [RPE] atrophy) between the groups was analyzed. Patient and disease characteristics were summarized as the median and interquartile range for continuous variables and the frequency and percentage for categorical variables. Comparisons were made using the Wilcoxon rank sum test for continuous variables and either Fisher's exact test or the χ² test for categorical variables with a p value threshold of 0.05 for statistical significance. Growth rate (change in basal dimension/12 months) diagnostic of SCM was quantified.

Main Outcome Measures

The primary aim of this study was to test the hypothesis that "growth" was diagnostic of SCM with the secondary aim of quantifying the malignant "growth rate" (growth rate of SCM).

Results

The clinical characteristics among all 3 groups were similar except more patients with symptoms (68 vs. 20 vs. 42%, p = 0.004) and juxtapapillary location (p = 0.03) were in the pathology group than in the growth-confirmed group. Those in the combined and growth-confirmed groups had more patients with drusen (11 vs. 60 vs. 50%, p = 0.003) and RPE atrophy (11 vs. 23 vs. 67%, p = 0.003), respectively, than in the pathology group. The median time to detect growth was 9 months (range 3-26 months). The mean growth rate in basal dimension was 1.8 mm/12 months (range, 0.0-7.4 mm; [95% CI: 1.32-2.28]).

Conclusions and Relevance

Choroidal melanocytic lesions exhibiting a defined growth rate can be clinically diagnosed as SCM without a need for biopsy.

Long non-coding RNA terminal differentiation-induced non-coding RNA regulates cisplatin resistance of choroidal melanoma by positively modulating extracellular signal-regulated kinase 2 via sponging microRNA-19b-3p

In the present study, we aimed to investigate the role of long non-coding RNA terminal differentiation-induced non-coding RNA (TINCR) in cisplatin (DDP) resistance of choroidal melanoma (CM) and the potential molecular mechanisms. CM and non-CM tissues were collected from 60 CM patients. DDP-resistant CM cells were obtained by selection with linearly increased DDP treatment. The expression levels of TINCR, microR-19b-3p (miR-19b-3p), and extracellular signal-regulated kinase 2 (ERK-2) were detected by quantitative real-time PCR. Cholecystokinin octapeptide (CCK-8) assay was utilized to detect chemosensitivity and cell viability. Flow cytometry analysis was performed to detect apoptotic cells. The protein levels of Bax, Bcl-2, cleaved-caspase-3, ERK-2, and nuclear factor-kappa B p65 were measured by Western blot. RNA immunoprecipitation (RIP) and dual-luciferase reporter assays were performed to determine the relationship among TINCR, miR-19b-3p, and ERK-2. The results showed that the levels of TINCR and ERK-2 were markedly increased in DDP-resistant CM tissues and cells, while miR-19b-3p level was significantly reduced. TINCR knockdown reduced DDP resistance and cell viability and promoted cell apoptosis, while TINCR overexpression exhibited opposite effects. TINCR and ERK-2 were direct targets of miR-19b-3p. Further experiments revealed that TINCR enhanced DDP resistance in CM cells by regulating the miR-19b-3p/ERK-2/NF-kb axis. Taken together, our study revealed a critical role of TINCR in regulating DDP resistance in CM and suggested that TINCR is a potential cisplatin-resistant CM therapeutic target.

Small Choroidal Melanoma: Correlation between Clinical Characteristics and Metastatic Potential

IMPORTANCE

Diagnosis of small choroidal melanoma is based upon clinical features and presence of factors predictive of local malignant growth. Prognostic biopsy quantifies risk of metastasis.

OBJECTIVE

The aim of this study is to explore relationship between clinical characteristics and metastatic potential of a small choroidal melanoma.

DESIGN

Retrospective review of 53 patients with small choroidal melanoma treated in a tertiary oncology clinic. Patients were derived from 3 cohorts, with pathologic confirmation, with growth confirmation, and those treated only on clinical basis. Based upon prognostic biopsy outcomes, each case was classified into low or high metastatic potential groups. Distribution of clinical characteristics such as age, laterality, symptoms, tumor dimensions, tumor distance from optic nerve and fovea, presence of surface orange pigment, drusen, retinal pigment epithelial atrophy, and subretinal fluid was analyzed between metastatic groups.

MAIN OUTCOME MEASURES

Distribution of clinical characteristics between low or high metastatic potential groups was analyzed.

RESULTS

A total of 53 patients [mean age, 61 years (range, 27-81 years); 32 (60%) men and 21 (40%) women] were classified into pathology confirmed group (n = 13), growth confirmed group (n = 26), and with clinical group (n = 14). Prognostic biopsy in the growth, pathology, and clinical groups revealed low metastatic potential in 23, 10, and 11 patients, respectively, and high metastatic potential in 3 patients in each group. Distribution of clinical characteristics between low or high metastatic potential groups was not statistically significantly different.

CONCLUSION

Clinical characteristics do not identify metastatic potential of a small choroidal melanoma.

White Paper on Ophthalmic Imaging for Choroidal Nevus Identification and Transformation into Melanoma

Purpose

To discuss the evolution of noninvasive diagnostic methods in the identification of choroidal nevus and determination of risk factors for malignant transformation as well as introduce the novel role that artificial intelligence (AI) can play in the diagnostic process.

Methods

White paper.

Results

Longstanding diagnostic methods to stratify benign choroidal nevus from choroidal melanoma and to further determine the risk for nevus transformation into melanoma have been dependent on recognition of key clinical features by ophthalmic examination. These risk factors have been derived from multiple large cohort research studies over the past several decades and have garnered widespread use throughout the world. More recent publications have applied ocular diagnostic testing (fundus photography, ultrasound examination, autofluorescence, and optical coherence tomography) to identify risk factors for the malignant transformation of choroidal nevus based on multimodal imaging features. The widespread usage of ophthalmic imaging systems to identify and follow choroidal nevus, in conjunction with the characterization of malignant transformation risk factors via diagnostic imaging, presents a novel path to apply AI.

Conclusions

AI applied to existing ophthalmic imaging systems could be used for both identification of choroidal nevus and as a tool to aid in earlier detection of transformation to malignant melanoma.

Translational Relevance

Advances in AI models applied to ophthalmic imaging systems have the potential to improve patient care, because earlier detection and treatment of melanoma has been proven to improve long-term clinical outcomes.

Circulating tumor DNA tracking through driver mutations as a liquid biopsy-based biomarker for uveal melanoma

BACKGROUND

Uveal melanoma (UM) is the most common intraocular tumor in adults. Despite good primary tumor control, up to 50% of patients develop metastasis, which is lethal. UM often presents asymptomatically and is usually diagnosed by clinical examination and imaging, making it one of the few cancer types diagnosed without a biopsy. Hence, alternative diagnostic tools are needed. Circulating tumor DNA (ctDNA) has shown potential as a liquid biopsy target for cancer screening and monitoring. The aim of this study was to evaluate the feasibility and clinical utility of ctDNA detection in UM using specific UM gene mutations.

METHODS

We used the highly sensitive digital droplet PCR (ddPCR) assay to quantify UM driver mutations (GNAQ, GNA11, PLCβ4 and CYSTLR2) in cell-free DNA (cfDNA). cfDNA was analyzed in six well established human UM cell lines with known mutational status. cfDNA was analyzed in the blood and aqueous humor of an UM rabbit model and in the blood of patients. Rabbits were inoculated with human UM cells into the suprachoroidal space, and mutated ctDNA was quantified from longitudinal peripheral blood and aqueous humor draws. Blood clinical specimens were obtained from primary UM patients (n = 14), patients presenting with choroidal nevi (n = 16) and healthy individuals (n = 15).

RESULTS

The in vitro model validated the specificity and accuracy of ddPCR to detect mutated cfDNA from UM cell supernatant. In the rabbit model, plasma and aqueous humor levels of ctDNA correlated with tumor growth. Notably, the detection of ctDNA preceded clinical detection of the intraocular tumor. In human specimens, while we did not detect any trace of ctDNA in healthy controls, we detected ctDNA in all UM patients. We observed that UM patients had significantly higher levels of ctDNA than patients with nevi, with a strong correlation between ctDNA levels and malignancy. Noteworthy, in patients with nevi, the levels of ctDNA highly correlated with the presence of clinical risk factors.

CONCLUSIONS

We report, for the first time, compelling evidence from in vitro assays, and in vivo animal model and clinical specimens for the potential of mutated ctDNA as a biomarker of UM progression. These findings pave the way towards the implementation of a liquid biopsy to detect and monitor UM tumors.

Application of Multimodal and Molecular Imaging Techniques in the Detection of Choroidal Melanomas

Choroidal melanomas are the most common ocular malignant tumors worldwide. The onset of such tumors is insidious, such that affected patients often have no pain or obvious discomfort during early stages. Notably, enucleation is required for patients with a severe choroidal melanoma, which can seriously impact their quality of life. Moreover, choroidal melanomas metastasize early, often to the liver; this eventually causes affected patients to die of liver failure. Therefore, early diagnosis of choroidal melanomas is extremely important. Unfortunately, an early choroidal melanoma is easily confused with a choroidal nevus, which is the most common benign tumor of the eye and does not often require surgical treatment. This review discusses recent advances in the use of multimodal and molecular imaging to identify choroidal melanomas and choroidal nevi, detect early metastasis, and diagnose patients with choroidal melanomas.

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.

Follow the nevus: the cost-utility of monitoring for growth of choroidal nevi

AIM

To develop a model to evaluate the cost-utility of choroidal nevi monitoring recommendations with varying clinical risk factors.

METHODS

A Markov model was created to evaluate the cost-utility in cost per quality-adjusted life-year ($/QALY) for monitoring patients with choroidal nevus. This probabilistic model was applied both to a hypothetically monitored and unmonitored group of patients beginning at different ages and with varying clinical risk factors of the nevus. Duration of screening was modeled for the remainder of the patients' life expectancy. Best available clinical data on the prevalence and incidence of choroidal nevi/melanoma, and relative risk of nevus transformation were combined with the initial and downstream costs of screening, downstream costs of melanoma-related mortality, and QALY saved by monitoring, to estimate the best monitoring regimen. Main outcome measures were average $/QALY saved by consensus recommended monitoring scenarios for the duration of a patient's remaining life expectancy in comparison with no follow-up, and the cost-utility of modified regimens.

RESULTS

The $/QALY of the recommended monitoring scenarios varied substantially based on nevus clinical risk factors, patient age, frequency of follow-up, and objective testing utilized. The $/QALY for the recommended monitoring scenario of a flat nevus without risk factors in a 60-year-old patient was $77 180. The $/QALY for monitoring a nevus with 3 clinical risk factors in a 60-year-old patient was $85 393. The $/QALY values for differently-aged patients were larger, and intermediate degrees of risk factors for nevus growth varied, depending largely upon the specifics of the modeled monitoring scenarios.

CONCLUSION

The average $/QALY of currently recommended monitoring scenarios fall within economically acceptable standards and could provide insight for formulating appropriate clinical strategies. Cost-utility could be enhanced by targeting higher risk groups and considering less frequent monitoring for the lower risk groups.