Immunomagnetic detection of micrometastatic cells in bone marrow of uveal melanoma patients: a paradox

Heterogeneity and molecular landscape of melanoma: implications for targeted therapy

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

A Case Report of Management of Medulloepithelioma of the Ciliary Body and Iris without Recurrence over an Observation Period of Twenty Years

Intraocular medulloepithelioma is a rare embryonal tumor that is believed to arise from the epithelium of the medullary tube. We report a 37-year-old female with medulloepithelioma presented at the age of 17 with a one-month history of left-sided visual deterioration and visible iris lesion. Birth history and medical and family histories were insignificant. The left eye revealed a vascularized iris mass. Further examination revealed a grey-white ciliary body mass and a subluxated lens with best-corrected visual acuity (BCVA) of 0.5. The patient underwent partial lamellar corneo-sclerouvectomy. The histological and electron microscopic findings revealed medulloepithelioma. To reduce the risk of recurrence of the probable malignant tumor, she was treated with Ruthenium plaque therapy about six weeks following surgical removal. Pars plana vitrectomy and lensectomy with laser photocoagulation of the peripheral retina were performed at the removal of the brachytherapy plaque. She regained her BCVA of 1.0 in her left eye 3.5 months following pars plana vitrectomy. At 20-year follow-up, no tumor recurrence was seen and her BCVA remained 1.0.

Circulating Neoplastic-Immune Hybrid Cells Predict Metastatic Progression in Uveal Melanoma

Background: Uveal melanoma is an aggressive cancer with high metastatic risk. Recently, we identified a circulating cancer cell population that co-expresses neoplastic and leukocyte antigens, termed circulating hybrid cells (CHCs). In other cancers, CHCs are more numerous and better predict oncologic outcomes compared to circulating tumor cells (CTCs). We sought to investigate the potential of CHCs as a prognostic biomarker in uveal melanoma. Methods: We isolated peripheral blood monocular cells from uveal melanoma patients at the time of primary treatment and used antibodies against leukocyte and melanoma markers to identify and enumerate CHCs and CTCs by immunocytochemistry. Results: Using a multi-marker approach to capture the heterogeneous disseminated tumor cell population, detection of CHCs was highly sensitive in uveal melanoma patients regardless of disease stage. CHCs were detected in 100% of stage I-III uveal melanoma patients (entire cohort, n = 68), whereas CTCs were detected in 58.8% of patients. CHCs were detected at levels statically higher than CTCs across all stages (p = 0.05). Moreover, CHC levels, but not CTCs, predicted 3 year progression-free survival (p < 0.03) and overall survival (p < 0.04). Conclusion: CHCs are a novel and promising prognostic biomarker in uveal melanoma.

Metastatic uveal melanoma: The final frontier

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

Identification of survival-related genes and a novel gene-based prognostic signature involving the tumor microenvironment of uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults and almost fifty percent of patients subsequently develop systemic metastases usually involving the liver. The tumor microenvironment (TME) is crucial to the initiation and progression of tumors. In the present study, we comprehensively evaluated the TME of primary UM samples from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database by using several bioinformatic algorithms. The prognostic value of immune score and infiltrating immune cells in the TME were evaluated. Differentially expressed genes between the low- and high-immune score groups were also identified. The majority of tumor-infiltrating lymphocytes in UM have been determined to be activated CD8 + T cells. Therefore, weighted gene co-expression network analysis (WGCNA) was performed to identify the co-expression modules and genes significantly associated with the level of infiltrating CD8 + T cells in UM. Survival-related genes involved in the TME were identified by univariate Cox regression analysis. Furthermore, an eight-gene-based prognostic signature was established in the training dataset TCGA-UM via Lasso-penalized and multivariate Cox regression analyses. The predictive value of this signature was validated in two testing datasets. Besides, a nomogram was established to serve clinical practice. Moreover, hub genes involved in the infiltrating CD8 + T cells were identified and a potential targeted therapy for preventing metastasis of UM was proposed based on the results. In summary, our results provided a robust gene-based prognostic signature for predicting prognosis of UM patients and proposed a potential targeted therapy for preventing UM metastasis.

Applying Single-Cell Technology in Uveal Melanomas: Current Trends and Perspectives for Improving Uveal Melanoma Metastasis Surveillance and Tumor Profiling

Uveal melanoma (UM) is the most common primary adult intraocular malignancy. This rare but devastating cancer causes vision loss and confers a poor survival rate due to distant metastases. Identifying clinical and molecular features that portend a metastatic risk is an important part of UM workup and prognostication. Current UM prognostication tools are based on determining the tumor size, gene expression profile, and chromosomal rearrangements. Although we can predict the risk of metastasis fairly accurately, we cannot obtain preclinical evidence of metastasis or identify biomarkers that might form the basis of targeted therapy. These gaps in UM research might be addressed by single-cell research. Indeed, single-cell technologies are being increasingly used to identify circulating tumor cells and profile transcriptomic signatures in single, drug-resistant tumor cells. Such advances have led to the identification of suitable biomarkers for targeted treatment. Here, we review the approaches used in cutaneous melanomas and other cancers to isolate single cells and profile them at the transcriptomic and/or genomic level. We discuss how these approaches might enhance our current approach to UM management and review the emerging data from single-cell analyses in UM.

Monosomy 3 Influences Epithelial-Mesenchymal Transition Gene Expression in Uveal Melanoma Patients; Consequences for Liquid Biopsy

Despite outstanding advances in diagnosis and the treatment of primary uveal melanoma (UM), nearly 50% of UM patients develop metastases via hematogenous dissemination, driven by the epithelial-mesenchymal transition (EMT). Despite the failure in UM to date, a liquid biopsy may offer a feasible non-invasive approach for monitoring metastatic disease progression and addressing protracted dormancy. To detect circulating tumor cells (CTCs) in UM patients, we evaluated the mRNA expression of EMT-associated transcription factors in CD45-depleted blood fraction, using qRT-PCR. ddPCR was employed to assess UM-specific GNA11, GNAQ, PLCβ4, and CYSLTR2 mutations in plasma DNA. Moreover, microarray analysis was performed on total RNA isolated from tumor tissues to estimate the prognostic value of EMT-associated gene expression. In total, 42 primary UM and 11 metastatic patients were enrolled. All CD45-depleted samples were negative for CTC when compared to the peripheral blood fraction of 60 healthy controls. Tumor-specific mutations were detected in the plasma of 21.4% patients, merely, in 9.4% of primary UM, while 54.5% in metastatic patients. Unsupervised hierarchical clustering of differentially expressed EMT genes showed significant differences between monosomy 3 and disomy 3 tumors. Newly identified genes can serve as non-invasive prognostic biomarkers that can support therapeutic decisions.

Liquid Biopsy in Uveal Melanoma: Are We There Yet?

In the era of precision oncology, major strides are being made to use individual tumor information for clinical decision-making. Differing from traditional biopsy methods, the emerging practice of liquid biopsy provides a minimally invasive way of obtaining tumor cells and derived molecules. Liquid biopsy provides a means to detect and monitor disease progression, recurrence, and treatment response in a noninvasive way, and to potentially complement classical biopsy. Uveal melanoma (UM) is a unique malignancy, with diagnosis heavily reliant on imaging, few repeat biopsies, and a high rate of metastasis, which occurs hematogenously and often many years after diagnosis. In this disease setting, a noninvasive biomarker to detect, monitor, and study the disease in real time could lead to better disease understanding and patient care. While advances have been made in the detection of tumor-disseminated components, sensitivity and specificity remain important challenges. Ambiguity remains in how to interpret current findings and in how liquid biopsy can have a place in clinical practice. Related publications in UM are few compared to other cancers, but with further studies we may be able to uncover more about the biology of disseminated molecules and the mechanisms involved in the progression to metastasis.

Analysis of monosomy-3 in immunomagnetically isolated circulating melanoma cells in uveal melanoma patients

Monosomy-3 in primary uveal melanoma (UM) is associated with a high risk of metastasis and mortality. Although circulating melanoma cells (CMC) can be found in most UM patients, only approximately 50% of the patients develop metastases. We utilized a novel immuno-FISH assay to detect chromosome-3 in intact CMC isolated by dual immunomagnetic enrichment. Circulating melanoma cells were detected in 91% of the patients (n = 44) with primary non-metastatic UM, of which 58% were positive for monosomy-3. The monosomy-3 status of CMC corresponded to the monosomy-3 status of the primary tumor in 10 of the 11 patients where this could be tested. Monosomy-3 in the CMC was associated with an advanced tumor stage (P = 0.046) and was detected in all four patients who developed metastasis within the follow-up period of 4 yr. This non-invasive technique may enable the identification of UM patients at risk for metastasis particularly when a primary tumor specimen is unavailable.

The Results of Stricter Inclusion Criteria in an Immunomagnetic Detection Study of Micrometastatic Cells in Bone Marrow of Uveal Melanoma Patients - Relevance for Dormancy

Approximately 50% of uveal melanoma patients develop metastases. We want to evaluate the effect of stricter criteria on our data from our previous study correlating survival and bone marrow (BM) micrometastasis results using our immunomagnetic separation (IMS) method. Mononuclear cell fractions (MNC) isolated from BM were examined for tumour cells and the patients were classified as BM positive (BM+) or BM negative (BM-). The study originally included 328 consecutive patients with uveal melanoma from 1997 to 2006. The cohort was limited to 217 patients when we introduced cyto- or histopathological verification of melanoma cells in the patient as a main new criterion for inclusion. Tumour cells were found in BM-samples in 38.7% (95% CI, 32-45) at enrolment. Until the latest work-up 43.8% (95% CI, 38-50) of patients had developed melanoma metastases. After a minimum follow-up time of 8.5 years, 60.4% (95% CI, 54-66) of patients had died. The causes were: melanoma metastases 69.5%, another type of cancer 5.4% and non-cancerous causes 19.5%. Overall median survival was shorter for the BM- patients (11.3 years) (95% CI, 10-12) compared to the BM+ (16.5 years) (95% CI, 12-14), p = 0.04, log rank test. All-cause mortality and specific melanoma mortality estimated after 12 year follow-up showed a highly significant difference comparing BM- and BM+, p = 0.010 and p = 0,017, respectively. IMS yields a high fraction of BM+ samples due to micrometastasis at diagnosis and these cells appear to have a positive prognostic impact strengthening our previous report. The late recurrences support the concept of tumour dormancy.

Patterns of care and outcomes of proton and eye plaque brachytherapy for uveal melanoma: Review of the National Cancer Database

PURPOSE

To examine national practice patterns and outcomes of eye plaque brachytherapy compared to proton external beam radiotherapy in the treatment of choroid melanoma.

METHODS AND MATERIALS

Demographic and clinical data for 1224 patients with choroid melanoma treated with either brachytherapy or proton beam therapy from 2004 to 2013 were obtained from the National Cancer Database. Logistic regression and propensity score matching was used to create a 1:1 matched cohort. Kaplan-Meier and Cox regression analyses were performed to evaluate survival in brachytherapy and proton groups.

RESULTS

Median followup was 37 and 29 months for brachytherapy and protons, respectively. Most patients were treated with brachytherapy (n = 996) vs. protons (n = 228). Proton patients came from more urban, affluent, and educated zip codes, and they were more likely to be treated at an academic center (all p < 0.004). In the propensity-score matched cohort, 2-year overall survival was 97% vs. 93%, and 5-year overall survival was 77% vs. 51% for brachytherapy and protons, respectively (p = 0.008). Multivariate Cox regression found older age (hazard ratio [HR] = 1.06, 95% confidence interval (CI) = 1.03-1.09), larger tumor diameter (12-18 mm, HR = 2.48, 95% CI = 1.40-4.42, >18 mm, HR = 6.41, 95% CI = 1.45-28.35), and protons (HR = 1.89, 95% CI = 1.06-3.37) were negative prognosticators of survival.

CONCLUSIONS

Patients selected for proton treatment have inferior survival outcomes compared to brachytherapy in this retrospective analysis. There may be unaccounted variables that influence survival, warranting further prospective studies.

Bilateral uveal melanomas with different gene expression detected with 7 years interval

PURPOSE

To report a bilateral uveal melanoma detected in a micrometastasis study.

METHOD

Case report.

RESULTS

At enucleation of a circumpapillary amelanotic mixed melanoma in a patient with ocular melanocytosis, a pigmented lesion in the other eye was detected, thought to be a naevus. BAP1 was positive showing nuclear staining of the tumour cells. Seven years later the naevus showed growth and development of a retinal detachment. FNAB disclosed monosomy 3 in the spindle tumour cells.

CONCLUSION

A case of bilateral melanoma with long-term survival without metastatic diseases is reported. Different gene expressions in the two eyes were revealed. The case is a reminder that follow-up over years is essential in patients with a uveal melanoma, especially with ocular melanocytosis.