Clinical treatment options for early-stage and advanced conjunctival melanoma

Curing Stage IV Melanoma: Where Have We Been and Where Are We?

Little more than 10 years ago, metastatic melanoma was considered to have one of the poorest cancer outcomes, associated with a median overall survival of 6-8 months. Cytotoxic chemotherapy offered modest response rates of 20%-30%, but no clear survival benefit. Patients were routinely enrolled in clinical trials as their first-line therapy in the search for effective novel therapeutics. Remarkable developments in molecular biology, cancer genomics, immunology, and drug discovery have dominated the early part of the 21st century, and nowhere have the benefits been better realized than in the transformation of outcomes for patients with metastatic melanoma: since 2011, 14 new agents have been approved that significantly increase survival, with long-term remissions and, possibly now, potential for cure. Even so, there is still much work to be done, given that most treated patients still die of their disease. Although most survival gains have so far been realized for cutaneous melanoma, improving treatment options for those 10% of patients with rarer, noncutaneous melanomas is a high priority. Key novel therapeutic approaches aimed at improving outcomes with potential for curing patients with melanoma are considered.

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%.

Factors affecting recurrence and metastasis in conjunctival melanoma

PURPOSE

To evaluate clinical and demographic characteristics and factors affecting recurrence, metastasis, and survival in conjunctival melanoma (CM).

METHODS

The clinical records of 45 patients who were treated for CM between October 1998 and June 2022 were retrospectively evaluated. Age, gender, presence of underlying conjunctival nevus-primary acquired melanosis (PAM), tumor stage according to the 8th edition of the American Joint Committee on Cancer (AJCC) staging system, tumor basal diameter, tumor thickness, lymph node (LN) involvement, metastasis, presence of tumor at the surgical margin, treatment method, need for adjuvant therapy, local tumor control, recurrence, and survival were recorded.

RESULTS

Twenty-one (46.7%) patients were female and 24 (53.3%) patients were male. The mean age at diagnosis was 53.2 ± 16.1 years. Median follow up time was 12 (1-300) months. Fifteen (33.3%) patients had conjunctival PAM; 2 (4.4%) patients had conjunctival nevus. The tumor stage was T1 in 24 (55.8%), T2 in 13 (30.2%), and T3 in 6 (14.0%) of the cases. The T stage in 2 cases could not be determined. For stage T1 and T2 CM, in addition to excisional biopsy (EB) and cryotherapy, alcohol epitheliectomy (AE) was performed in 17 cases (37.8%), superficial sclerectomy (SS) was performed in 7 (15.6%), and amnion membrane transplantation (AMT) due to a large conjunctival defect in 9 (20.0%). Six (14.0%) T3 cases underwent primary exenteration. Positive surgical margins were observed in 23 (51.1%) of the excised tumors at histopathologic examination. Adjuvant topical mitomycin-C (MMC) was used in 7 (30.4%) and strontium-90 episcleral brachytherapy in 4 (17.4%) of the 23 cases with tumor-positive borders. During the follow-up, recurrence was seen in 14 (31.1%) cases. According to Kaplan Meier analysis, the mean time to recurrence development was 90.5 ± 16.1 months and the 5-year recurrence free rate was 52.0%. Fourteen of the recurrent cases underwent EB + cryotherapy, 3 underwent AE + SS, and 3 underwent secondary exenteration. Metastasis and LN involvement occurred in 11 (24.4%) and 8 (17.8%) of the cases, respectively. Four (8.9%) cases expired during follow-up. According to Kaplan-Meier analysis, the mean time to metastasis was 106.2 ± 17.3 months and the 5-year metastasis free rate was 52.0%. While recurrence was more frequent in CM developing from PAM/nevus, metastasis was more frequent in men and those with LN involvement.

CONCLUSION

Conjunctival melanoma was a malignant tumor with high recurrence and metastasis rates. Precursor nevus/PAM is a risk factor for recurrence, while male gender and regional LN involvement were risk factors for metastasis in this study.

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).

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.

Metastasis of Conjunctival Melanoma to the Cardiac Atrium: A Case Report

The authors present an unreported case of malignant conjunctival melanoma with metastasis to the right cardiac atrium. A 67-year-old woman with history of conjunctival melanoma of the OS presented with asymptomatic recurrence with new extension to the fornix. Surgical management was planned; however, the patient was admitted to the hospital with symptoms of heart and respiratory failure. She was found to have a large mass in the right atrium. The mass was resected and was found to be metastatic conjunctival melanoma. The patient received chemotherapy and her symptoms have improved. This case highlights the high recurrence rate of conjunctival melanoma and the importance of tumor surveillance.

Publication trends of research on conjunctival melanoma during 1997–2022: A 25-year bibliometric study

Background

Conjunctival melanoma (CM) is a life-threatening ocular tumor with a high rate of local recurrence and metastasis. Our objective is to analyze research trends in CM field and compare contributions from different countries, institutions and authors.

Methods

We extracted all CM-related publications published from 1997 to 2022 from the Web of Science database and applied Microsoft Excel and VOSviewer to review publication data, analyze publication trends, and visualize relevant data.

Results

A total of 708 publications were identified. The United States contributed the most publications (280) and citations (8,781 times) with the highest H-index value (47). The Ophthalmic Plastic and Reconstructive Surgery, British Journal of Ophthalmology, American Journal of Ophthalmology and Cornea were the most productive journal concerning CM, and Shields CL, Shields JA, Jager MJ as well as Finger PT had published the most papers in the field. Keywords were classified into three clusters: clinical research, management-related research and genetic research. The keywords “primary acquired melanosis”, “metastasis” and “BRAF mutations” were most frequently emerged. According to the average appearing year (AAY), targeted therapy (AAY of 2019.0) and nivolumab (AAY of 2018.7) were identified as the main focuses of the field in the near future.

Conclusion

In the past 25 years, the United States, Germany, England and the Netherlands held the leading position in the CM research. A group of scholars made important contributions to CM research and will continue to guide cutting-edge research. Treatments that have been shown to be effective for advanced cutaneous melanoma, such as targeted therapy and immunotherapy, are potential focuses for future CM research.

Use of interferon alpha 2b to manage conjunctival primary acquired melanosis and conjunctival melanoma

Primary acquired melanosis (PAM) is acquired conjunctival pigmentation that can give rise to conjunctival melanoma (CM), a malignant tumor of the bulbar and palpebral conjunctiva or the caruncle. Surgical excision is the treatment of choice for this neoplasm. Topical chemotherapy is also used for patients with PAM with atypia or CM, hand in patients with recurrent or extensive disease, this may be an important option. Of the several chemotherapeutic drugs used, topical interferon alpha 2b (IFN-α2b) has become popular because of its low toxicity. Clinical evidence from case reports and case series supports the efficacy of IFN-α2b as the preferred adjuvant treatment for PAM and CM. In addition, topical IFN-α2b has been successfully applied to melanocytic tumors refractory to other treatments, such as cryotherapy and topical mitomycin C. In patients with locally advanced CM, the combination of IFN-α2b and systemic immunotherapy may serve as an alternative to exenteration. Given the low frequency of CM, long-term multicenter studies are needed to demonstrate the efficacy of IFN-α2b for preventing local recurrence and distant metastasis.

Small but Challenging Conjunctival Melanoma: New Insights, Paradigms and Future Perspectives

Although its incidence has increased over the last decades, conjunctival melanoma (CM) remains a rare but challenging periocular malignancy. While there is currently no recognized standard of care, "no-touch" surgical excision followed by adjuvant treatments is usually recommended. Despite its small size, managing CM is challenging for clinicians. The first challenge is the high risk of tumour local recurrence that occurs in about one third of the patients. The management of locally advanced CM (≥T2) or multiple recurrences may require mutilating surgeries such as orbital exenteration (OE). The second challenge is the metastatic spread of CM that occurs in about one quarter of patients, regardless of whether complete surgical excision is performed or not. This highlights the infiltrative and highly aggressive behaviour of CM. Recently, attention has been directed towards the use of eye-sparing strategies to avoid OE. Initially, wide conservative surgeries followed by customized brachytherapy or radiotherapy have appeared as viable strategies. Nowadays, new biological insights into CM have revealed similarities with cutaneous melanoma. These new findings have allowed clinicians to reconsider the management of locally advanced CM with "medical" eye-sparing treatment as well as the management of metastatic spread. The aim of this review was to summarize the current and future perspectives of treatment for CM based on recent biological findings.

The Abscopal Effect in the Era of Checkpoint Inhibitors

Therapy targeting immune checkpoints represents an integral part of the treatment for patients suffering from advanced melanoma. However, the mechanisms of resistance are responsible for a lower therapeutic outcome than expected. Concerning melanoma, insufficient stimulation of the immune system by tumour neoantigens is a likely explanation. As shown previously, radiotherapy is a known option for increasing the production of tumour neoantigens and their release into the microenvironment. Consequently, neoantigens could be recognized by antigen presenting cells (APCs) and subjected to effector T lymphocytes. Enhancing the immune reaction can trigger the therapeutic response also at distant metastases, a phenomenon known as an abscopal effect (from “ab scopus”, that is, away from the target). To illustrate this, we present the case of a 78-year old male treated by anti-CTLA-4/ipilimumab for metastatic melanoma. The patient received the standard four doses of ipilimumab administered every three weeks. However, the control CT scans detected disease progression in the form of axillary lymph nodes metastasis and liver metastasis two months after ipilimumab. At this stage, palliative cryotherapy of the skin metastases was initiated to alleviate the tumour burden. Surprisingly, the effect of cryotherapy was also observed in untreated metastases and deep subcutaneous metastases on the back. Moreover, we observed the disease remission of axillary lymph nodes and liver metastasis two months after the cryotherapy. The rarity of the abscopal effect suggests that even primed anti-tumour CD8⁺ T cells cannot overcome the tumour microenvironment’s suppressive effect and execute immune clearance. However, the biological mechanism underlying this phenomenon is yet to be elucidated. The elicitation of a systemic response by cryotherapy with documented abscopal effect was rarely reported, although the immune response induction is presumably similar to a radiotherapy-induced one. The report is a combination case study and review of the abscopal effect in melanoma treated with checkpoint inhibitors.

New Targeted Therapies and Immunotherapies for Locally Advanced Periocular Malignant Tumours: Towards a New 'Eye-Sparing' Paradigm?

The management of periocular skin malignant tumours is challenging. Surgery remains the mainstay of treatment for localised eyelid cancers. For more locally advanced cancers, especially those invading the orbit, orbital exenteration has long been considered the gold standard; however, it is a highly disfiguring and traumatic surgery. The last two decades have been marked by the emergence of a new paradigm shift towards the use of 'eye-sparing' strategies. In the early 2000s, the first step consisted of performing wide conservative eyelid and orbital excisions. Multiple flaps and grafts were needed, as well as adjuvant radiotherapy in selected cases. Although being incredibly attractive, several limitations such as the inability to treat the more posteriorly located orbital lesions, as well as unbearable diplopia, eye pain and even secondary eye loss were identified. Therefore, surgeons should distinguish 'eye-sparing' from 'sight-sparing' strategies. The second step emerged over the last decade and was based on the development of targeted therapies and immunotherapies. Their advantages include their potential ability to treat almost all tumours, regardless of their locations, without performing complex surgeries. However, several limitations have been reported, including their side effects, the appearance of primary or secondary resistances, their price and the lack of consensus on treatment regimen and exact duration. The aim of this article was to review the evolution of the management of locally advanced periocular malignant tumours over the last three decades and highlight the new paradigm shift towards the use of 'eye-sparing' strategies.

m6A RNA hypermethylation-induced BACE2 boosts intracellular calcium release and accelerates tumorigenesis of ocular melanoma

Ocular melanoma, including uveal melanoma (UM) and conjunctival melanoma (CM), is the most common and deadly eye cancer in adults. Both UM and CM originate from melanocytes and exhibit an aggressive growth pattern with high rates of metastasis and mortality. The integral membrane glycoprotein beta-secretase 2 (BACE2), an enzyme that cleaves amyloid precursor protein into amyloid beta peptide, has been reported to play a vital role in vertebrate pigmentation and metastatic melanoma. However, the role of BACE2 in ocular melanoma remains unclear. In this study, we showed that BACE2 was significantly upregulated in ocular melanoma, and inhibition of BACE2 significantly impaired tumor progression both in vitro and in vivo. Notably, we identified that transmembrane protein 38B (TMEM38B), whose expression was highly dependent on BACE2, modulated calcium release from endoplasmic reticulum (ER). Inhibition of the BACE2/TMEM38B axis could trigger exhaustion of intracellular calcium release and inhibit tumor progression. We further demonstrated that BACE2 presented an increased level of N⁶-methyladenosine (m⁶A) RNA methylation, which led to the upregulation of BACE2 mRNA. To our knowledge, this study provides a novel pattern of BACE2-mediated intracellular calcium release in ocular melanoma progression, and our findings suggest that m⁶A/BACE2/TMEM38b could be a potential therapeutic axis for ocular melanoma.