Genetic characterization of advanced conjunctival melanoma and response to systemic treatment

[New systemic treatment approaches for conjunctival melanoma]

Conjunctival melanoma is a rare disease that nevertheless has a high tumor-associated mortality rate. A resection in sano with adjuvant local treatment currently represents the therapeutic gold standard and systemic treatment is used for metastasized conjunctival melanoma and/or very advanced nonresectable local findings. New knowledge on molecular changes in conjunctival melanoma shows a clear similarity to those of cutaneous melanoma. Therefore, many findings on new systemic forms of treatment for cutaneous melanoma can be transferred to conjunctival melanoma. In the clinical application BRAF/MEK inhibitors and immune checkpoint inhibitors are already in use and good response rates have been shown in small retrospective studies and case reports. Due to the rarity of conjunctival melanoma, there are no larger prospective studies comparing different systemic therapeutic agents. In a nonrandomized retrospective comparison, a better overall survival was shown for a combination of BRAF/MEK inhibitors (progression-free 1‑year survival probability of 54.7%; overall survival of 29.1 months) compared to a combination of PD1/CTLA4 antibodies (progression-free 1‑year survival probability of 42%; overall survival of 18 months). The current recommendation is to perform genomic profiling for every conjunctival melanoma, particularly to investigate a BRAF mutation. If a BRAF mutation is present, BRAF/MEK inhibitor treatment should preferably be initiated. Treatment with immune checkpoint inhibitors can be used in the case of BRAF-negative mutation status or treatment failure with BRAF/MEK inhibitors. Monotherapy with the CTLA4 antibody ipilimumab is not recommended due to its inferiority to PD1 antibodies. New knowledge in the genomic profiling of conjunctival melanoma could enable further targeted treatment options in the future.

Primary Treatment of Eyelid Conjunctival Melanoma with Immunotherapy: A Case Report

Conjunctival melanoma is a rare, life- and sight-threatening ocular malignancy sharing molecular features with cutaneous and mucosal melanoma. Despite current clinical approaches, high recurrence rates and frequent metastases pose significant challenges in management. Immune checkpoint inhibitors such as ipilimumab and nivolumab have revolutionized cutaneous melanoma treatment, but their efficacy in conjunctival melanoma remains largely unexplored. Herein, the authors present the case of metastatic palpebral conjunctival melanoma in a 59-year-old male successfully treated with a first-line combination of ipilimumab and nivolumab without adjuvant therapies or local surgeries. Local disease resolution was achieved after only 7 months of treatment, and the immune checkpoint inhibitor regimen was well-tolerated with limited systemic adverse effects and no ocular side effects.

Treatment of Conjunctival Melanoma Cell Lines With a Light-Activated Virus-Like Drug Conjugate Induces Immunogenic Cell Death

Purpose

Conjunctival melanoma (CJM) is a rare malignant ocular surface tumor, which often leads to local recurrences and metastases. In murine models of subcutaneous tumors, treatment with a novel virus-like drug conjugate (VDC; Bel-sar) showed a dual mechanism of action with direct tumor cell killing as well as stimulation of an antitumoral immune response. Bel-sar is currently being evaluated for the treatment of primary uveal melanoma and indeterminate nevi in a phase III clinical trial. We determined whether Bel-sar also has direct antitumor efficiency and a potential immunostimulatory capacity in CJM cells.

Methods

Three human tumor-derived CJM lines were used. Bel-sar's subcellular and intracellular locations were determined with tracers. Following light activation of Bel-sar, cytotoxicity and exposure of damage-associated molecular patterns (DAMPs) were assessed. Treated tumor cells were co-cultured with THP-1 derived macrophages to assess tumor-cell phagocytosis.

Results

Bel-sar was bound and internalized by CJM cells and subsequently found in the cell membrane, lysosome, Golgi apparatus, and mitochondria. Bel-sar activation induced near complete cell death with half-maximal inhibitory concentration (IC50) values between 30 pM and 60 pM. Finally, light-activated Bel-sar enhanced exposure of DAMPs, including calreticulin, heat shock protein 90, and stimulated phagocytosis by macrophages.

Conclusions

Treatment with a novel VDC (Bel-sar) induced pro-immunogenic cell death in all three CJM cell lines. The in vitro cytotoxicity was accompanied by exposure of DAMPs, suggesting Bel-sar is a potential treatment for CJM by a dual mechanism of action. This dual mechanism may provide a targeted and direct killing of tumor cells and induce an immune response which might decrease local recurrences and metastasis.

Conjunctival Melanoma: A Clinical Review and Update

Conjunctival melanoma (Co-M) is an aggressive, invasive eye and eyelid cancer. Its global incidence of ~1 in a million is increasing at a rate ratio of ~1.4, but this rises sharply in over 65-year-olds. Although rare, Co-M has a devastating impact on the lives of those who develop it. Co-M is often misdiagnosed or overlooked, leading to vision loss either from the destructive effects of the tumour or side effects of therapy, facial disfigurement from radical surgery, and death from metastases. Due to its rarity, there is limited evidence for diagnosis and management; hence, there is no standardised treatment and not all cases are referred to a specialised ocular oncology centre. Recent progress in cancer immunology and genetics have revolutionised the treatment of cutaneous melanomas, which share some similarities to Co-M. Importantly, a better understanding of Co-M and its precursor lesions is urgently needed to lead to the development of novel targeted and immunotherapies both for local tumour control and disseminated disease. This review aims to provide a comprehensive clinical overview of the current knowledge regarding Co-M, its epidemiology, pathogenesis, presentation, diagnosis and recent changes in the classification of its precursor lesions, management, and recent advances in novel biological therapies for personalised treatment of this disease.

Advances in Molecular Understanding of Ocular Adnexal Disease

The goal of this Special Issue is to provide comprehensive molecular biological data that aims to elucidate the molecular and epigenetic mechanisms operable in diseases of the ocular adnexa [...].

Targeted Therapy and Immunotherapy for Advanced Malignant Conjunctival Tumors: Systematic Review

PURPOSE

To review the outcomes of targeted therapy and immunotherapy in advanced conjunctival tumors, including conjunctival squamous cell carcinoma, conjunctival melanoma, and conjunctival lymphoma.

METHODS

A Pubmed database systematic search was performed between January 1999 and December 2022. The literature search was limited to studies published in English.

RESULTS

This review included 142 patients with advanced malignant conjunctival tumors from 42 articles. In the conjunctival squamous cell carcinoma group, 2 cases of advanced conjunctival squamous cell carcinoma treated with epidermal growth factor receptor inhibitors showed significant tumor size improvement after 7.5 months of follow-up. Among 7 cases treated with systemic immunotherapy, 5 cases (72%) had complete response (CR), 1 case (14%) showed partial response (PR), and 1 case (14%) had stable disease (SD) after 16 months. In the conjunctival melanoma group, among 18 cases treated with combined v-raf murine sarcoma viral oncogene homolog B1/mitogen-activated extracellular signal-regulated kinase inhibitors, 6 (33%) had CR, 5 (28%) had PR, 2 (11%) had SD, and 5 (28%) had progressive disease after 24.8 months of follow-up. Of 44 conjunctival melanoma cases treated with immunotherapy, 12 (28%) had CR, 9 (20%) had PR, 7(16%) had SD, and 16 (36%) had progressive disease after 14.2 months. Systemic Rituximab treatment for conjunctival lymphoma cases resulted in CR in 21 patients (63%), PR in 11 patients (33%), and SD in 1 patient (3%) after 20.5 months of follow-up. Intralesional Rituximab injections in 38 conjunctival lymphoma cases showed CR in 28 patients (75%), PR in 7 patients (19%), SD in 1 patient (2%), and progressive disease in 2 patients (4%) after 20.4 months of follow-up.

CONCLUSIONS

Despite limited clinical case reports and short-term follow-ups, targeted therapy and immunotherapy have shown promising results for advanced malignant conjunctival tumors.

Incidence and Mortality of Conjunctival Melanoma in Australia (1982 to 2014)

Purpose

The purpose of this study was to estimate the incidence and mortality of conjunctival melanoma in Australia from 1982 to 2014.

Methods

De-identified unit data for all cases of ocular melanoma were extracted from the Australian Cancer Database from 1982 to 2014. Conjunctival melanoma cases were extracted, and the incidence and mortality were analyzed. Incidence rates were age-standardized against the 2001 Australian Standard Population. Mortality was assessed using log-rank and Cox regression.

Results

From 1982 to 2014, there were 299 cases of conjunctival melanoma. The age-standardized incidence rate was 0.48 (95% confidence interval [CI] = 0.41 to 0.54) per million per year. Women (0.52, 95% CI = 0.42 to 0.62) had a higher incidence than men (0.42, 95% CI = 0.33 to 0.51). The incidence of conjunctival melanoma increased in men (+1.46%) and significantly women (+1.41%, P = 0.023) over the study period. The mean 5-, 10-, and 15-year disease-specific survival were 90%, 82%, and 80%, respectively, during the 33-year interval. Comparisons of survival among age, sex, and state revealed no significant differences when tested using log-rank or Cox regression.

Conclusions

In conclusion, we found an increase in the rate of conjunctival melanoma diagnoses in Australia from 1982 to 2014. Over the same period, disease survival remained unchanged at a mean of 90%.

Genetic Aspects of Conjunctival Melanoma: A Review

Conjunctival melanoma (CM) is a rare but aggressive cancer. Over the past decade, molecular studies using rapidly advancing technologies have increasingly improved our understanding of CM genetics. CMs are mainly characterized by dysregulated MAPK and PI3K/AKT/mTOR pathways, driven by commonly mutated (BRAF, NRAS, NF1) or less commonly mutated (KIT, PTEN) genes. Another group of genes frequently mutated in CMs include TERT and ATRX, with known roles in telomere maintenance and chromatin remodeling/epigenetic regulation. Uveal melanoma-related genes (BAP1, SF3B1, GNAQ/11) can also be mutated in CMs, albeit infrequently. Additional CM-related mutated genes have increasingly been identified using more comprehensive genetic analyses, awaiting further confirmation in additional/larger studies. As a tumor arising in a partly sun-exposed mucosal tissue, CM exhibits a distinct genomic profile, including the frequent presence of an ultraviolet (UV) signature (and high mutational load) and also the common occurrence of large structural variations (distributed across the genome) in addition to specific gene mutations. The knowledge gained from CM genetic studies to date has led to new therapeutic avenues, including the use of targeted and/or immuno-therapies with promising outcomes in several cases. Accordingly, the implementation of tumor genetic testing into the routine clinical care of CM patients holds promise to further improve and personalize their treatments. Likewise, a growing knowledge of poor prognosis-associated genetic changes in CMs (NRAS, TERT, and uveal melanoma signature mutations and chromosome 10q deletions) may ultimately guide future strategies for prognostic testing to further improve clinical outcomes (by tailoring surveillance and considering prophylactic treatments in patients with high-risk primary tumors).

Clinical features and prognosis of patients with metastatic ocular and orbital melanoma: A bi-institutional study

PURPOSE

Metastatic ocular and orbital melanomas are extremely rare. The clinical characteristics and standard treatments for these patients are not fully established.

MATERIALS AND METHODS

We retrospectively analyzed patients with metastatic ocular and orbital melanoma from Fudan University Shanghai Cancer Center and Eye & ENT Hospital of Fudan University between January 2012 and May 2022.

RESULTS

Overall, 51 patients with metastatic ocular and orbital melanoma were included. The most common primary sites were uvea (73%), followed by conjunctiva (22%), lacrimal sac (4%), and orbit (2%). Patients with uveal melanoma (UM) had a significantly younger age (48 vs. 68 years, p < 0.001), higher incidence of liver metastases (89% vs. 9%, p<0.001), a lower incidence of lymph nodes metastases (16% vs. 46%, p = 0.043) and a lower incidence of BRAF mutation (0% vs. 55%, p<0.001) compared with patients with conjunctival melanoma (CM). The overall response rate of the first-line treatment was 18%. Three of the four patients with BRAF-mutated CM responded to dabrafenib and trametinib treatment. The median progression-free survival (PFS) and overall survival (OS) of first-line treatment were 5.1 and 11.9 months, respectively. Among patients with liver metastases, liver-directed treatment was correlated with better patient PFS (p < 0.001) and OS (p < 0.001) after adjusting for number of metastatic sites and primary sites.

CONCLUSION

CM and UM have different characteristics. Patient with CM had a high incidence of BRAF mutation, and the treatment of BRAF and MEK inhibitors conferred clinical benefit. Liver directed therapies had a potential benefit in disease control in patients with liver metastases.

Risk factors and prognosis of orbital exenteration in conjunctival melanoma

OBJECTIVES

To identify the risk factors of orbital exenteration and to evaluate the prognosis of exenterated patients with conjunctival melanoma (CM).

METHODS

79 consecutive CM patients treated at our centre from January 2000 to September 2021 were included. The demographic, clinical and pathological characteristics were compared between eye-sparing patients and orbital exenteration patients. Main outcomes including progression-free survival (PFS), distant metastasis-free survival (DFS) and disease specific survival (DSS) were assessed in exenterated patients.

RESULTS

The mean follow-up period was 46 ± 39 months. Risk factors for orbital exenteration were identified as worse cT category (OR, 50.75; 95% CI, 5.40-477.07; P = 0.001) and greater tumour thickness (OR, 1.27; CI, 1.04-1.55; P = 0.02). Of the 32 patients who underwent orbital exenteration, three (9.4%) had local recurrence; six (18.8%) experienced regional metastasis; sixteen (50.0%) suffered distant metastasis and fifteen (46.9%) died of metastatic disease. In patients who received orbital exenteration, palpebral conjunctiva involvement (PFS: P < 0.01; DFS: P < 0.05; DSS: P = 0.04), histological ulceration (PFS: P = 0.03; DFS: P = 0.01; DSS: P = 0.03) and regression (PFS: P = 0.01; DFS: P < 0.01; DSS: P = 0.04) were identified as risk factors for poor prognosis. Caruncle involvement (P = 0.01) was also associated with increased risk of melanoma related mortality in exenterated patients.

CONCLUSIONS

Histopathological factors should be taken into account when formulating surgical plans for orbital exenteration and when evaluating patients' prognosis following exenteration. For CM patients with caruncle or palpebral conjunctiva involvement, orbital exenteration should be considered for unresectable disease.

Characterisation and outcome of RAC1 mutated melanoma

BACKGROUND

Activating hot spot R29S mutations in RAC1, a small GTPase influencing several cellular processes including cell proliferation and cytoskeleton rearrangement, have been reported in up to 9% of sun-exposed melanomas. Clinical characteristics and treatment implications of RAC1 mutations in melanoma remain unclear.

METHODS

We investigated the largest set (n = 64) of RAC1 mutated melanoma patients reported to date, including a retrospective single institution cohort (n = 34) from the University Hospital Essen and a prospective multicentre cohort (n = 30) from the translational study Tissue Registry in Melanoma (TRIM; CA209-578), for patient and tumour characteristics as well as therapy outcomes.

RESULTS

From 3037 sequenced melanoma samples screened RAC1 mutations occurred in ^∼2% of samples (64/3037). The most common RAC1 mutation was P29S (95%, 61/64). The majority of tumours had co-occuring MAP kinase mutations (88%, 56/64); mostly activating NRAS (47%, 30/64) mutations, followed by activating BRAF (28%, 18/64) and NF1 (25%, 16/64) mutations. RAC1 mutated melanomas were almost exclusively of cutaneous origin (84%, 54/64) or of unknown primary (MUP, 14%, 9/64). C > T alterations were the most frequent mutation type identified demonstrating a UV-signature for RAC1 mutated melanoma. Most patients with unresectable disease (39) received immune checkpoint inhibitors (ICI) (77%, 30/39). Objective response rate of first-line treatment in patients with stage III/IV disease was 21%; median overall survival was 47.8 months.

CONCLUSIONS

RAC1 mutated melanomas are rare, mostly of cutaneous origin and frequently harbour concomitant MAP kinase mutations, particularly in NRAS. Patients with advanced disease benefit from systemic treatment with ICI.