Conjunctival Melanoma: Outcomes based on the American Joint Committee on Cancer Clinical Classification (8th Edition) of 425 Patients at a Single Ocular Oncology Center

Conjunctival melanoma: Insights into classification, outcomes, and biomarkers

Conjunctival melanoma is quite rare, estimated at approximately 0.5 incidence per 1 million persons per year. This malignancy arises from a pre-existing nevus (7%), primary acquired melanosis (74%), or de novo without pre-existing condition (19%) and develops most often in patients with Fitzpatrick skin types I (23%) and II (62%). At initial presentation, the tumor size is approximately 13 mm in cross-sectional diameter and has 3-mm thickness, involving the bulbar (97%), forniceal (30%), tarsal (28%), or caruncular (11%) regions, often with corneal (54%) and rarely with orbital (4%) involvement. According to the eighth edition of the American Joint Committee on Cancer (AJCC), the tumor is classified as T1 (63%), T2 (18%), T3 (20%), and T4 (0%). Outcomes depend on several factors including patient age, AJCC classification, orbital invasion, and type of initial surgery, whereas tumor origin and Fitzpatrick skin type do not appear to impact outcomes. Older patients (≥70 years of age) demonstrate larger tumors, greater recurrence, and greater vision loss. Analysis of 425 patients by AJCC classification (T1 versus T2 versus T3) revealed increasing T category with greater lymph node metastasis (3% versus 13% versus 25%; P < .001), tumor-related systemic metastasis (13% versus 45% versus 40%; P < .001), and tumor-related death (8% versus 22% versus 37%; P < .001). Data of patients with orbital invasion revealed significantly greater 10-year rates of exenteration (P < .001), distant metastasis (P = .0005), and death (P = .001). Studies have demonstrated biomarkers related to conjunctival melanoma include mutations in BRAF, NRAS, ATRX, and NF1. Future therapies might be directed against these mutations or with small-molecule inhibitors and/or immunotherapy. In summary, conjunctival melanoma is a rare but ominous malignancy, imparting moderate risk for lymph node and systemic metastasis as well as death, depending on tumor features and classification. The first surgery is highly important in prevention of tumor seeding, recurrence, and metastasis.

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).

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.

Advances in conjunctival melanoma: clinical features, diagnostic modalities, staging, genetic markers, and management

Conjunctival melanoma, a rare malignancy of the ocular surface, is increasing in incidence. When small, straightforward excision with "no touch" surgery and cryotherapy at an experienced centre can provide excellent outcomes. When advanced, management is more complex and highly individualized. The risk of metastatic disease from conjunctival melanoma is as high as 30% and depends on tumour origin, American Joint Committee on Cancer (AJCC) classification, biomarkers, and perhaps most important, management technique. Metastatic disease can result in melanoma-associated death. Therefore, early detection and prompt directed treatment at an experienced centre are important for protection from metastasis. In this review, we provide an update on conjunctival melanoma clinical features, diagnostic modalities, AJCC staging, genetic markers, and the most critical, controlled management with minimization of tumour seeding. We detail the new era of characterization of conjunctival melanoma with molecular biomarkers that predict melanoma prognosis. This could lead to precision medicine with targeted approaches to specific mutations that improve patient survival. As we work together, the field of conjunctival melanoma is moving forward.

Conjunctival Melanoma in 430 Cases: Comparative Analysis of the Impact of Orbital Invasion on Tumor Recurrence, Metastasis, and Death

PURPOSE

To compare the clinical features at presentation and treatment outcomes of conjunctival melanoma by absence/presence of orbital invasion.

METHODS

A retrospective review of patients with conjunctival melanoma managed at a single tertiary referral center from April 18, 1974, to September 9, 2019.

RESULTS

Of 430 patients with conjunctival melanoma, 21 (5%) had orbital invasion at presentation. A comparison between the 2 groups (orbital invasion absent vs. present) revealed that the orbital invasion group had a higher frequency of prior eyelid incisional biopsy (5% vs. 24%, P = 0.006), greater tumor basal diameter (12.2 vs. 17.3, P = 0.009), greater tumor thickness (2.4 vs. 7.0, P < 0.001), more quadrants involved (1.8 vs. 2.5, P = 0.002), and more clock hours involved (4.4 vs. 5.8, P = 0.037). In addition, those with orbital invasion were more likely to undergo exenteration as primary treatment (1% vs. 24%, P < 0.001). Multivariate relative risk regression analysis revealed that variables predictive of orbital invasion included greater tumor thickness (P < 0.001) and greater involvement of the fornix (P = 0.031) and tarsus (P = 0.033). Outcomes revealed orbital invasion group with greater 5-year/10-year distant metastatic rate (16%/21% vs. 63%/63%, P = 0.005), and greater melanoma-related death rate (7%/13% vs. 38%/53%, P = 0.001).

CONCLUSIONS

Conjunctival melanoma with orbital invasion at presentation demonstrate larger, more extensive tumors involving the fornix or tarsus, and with greater rate of melanoma-related metastasis and death.

Conjunctival Melanocytic Lesions

CONTEXT.—

Conjunctival melanocytic lesions consist of a variety of neoplastic and nonneoplastic conditions. These include benign processes such as primary intraepithelial hypermelanosis and melanocytic hyperplasia, secondary forms of intraepithelial hypermelanosis and melanocytic hyperplasia, melanocytic nevi, melanocytic proliferations with malignant potential, and melanoma.

OBJECTIVE.—

To provide a concise yet comprehensive resource regarding the histopathologic diagnosis of conjunctival melanocytic lesions. We aim to detail and clarify the numerous classification schemes that exist for junctional melanocytic proliferations of the conjunctiva (known as primary acquired melanosis or PAM; also termed conjunctival melanocytic intraepithelial neoplasia or C-MIN). Although not uniformly adopted, C-MIN is classified by using a numeric system based on a defined set of criteria. A less complex scheme (conjunctival melanocytic intraepithelial lesion or CMIL) has recently been proposed by the World Health Organization. Additionally, we aim to update the reader regarding molecular features and prognostic indicators.

DATA SOURCES.—

Peer-reviewed literature and archived cases for illustration.

CONCLUSIONS.—

Accurate histologic classification is essential, as PAM/C-MIN/CMILs that have a significant potential to progress to invasive melanoma may be clinically indistinguishable from low-risk lesions. Conjunctival melanoma (CM) more closely resembles cutaneous melanoma in terms of its pathogenesis and molecular features, compared to melanoma arising at other mucosal sites or to uveal melanoma. Depth of invasion and ulceration status, among other factors, have emerged as important prognostic indicators in CM. Sentinel lymph node biopsy may provide further prognostic information. Lastly, integration of pathologic and clinical findings is essential at this anatomically sensitive location to determine appropriate clinical management.

IGF-1R is a molecular determinant for response to p53 reactivation therapy in conjunctival melanoma

As the p53 tumor suppressor is rarely mutated in conjunctival melanoma (CM), we investigated its activation as a potential therapeutic strategy. Preventing p53/Mdm2 interaction by Nutlin-3, the prototypical Mdm2 antagonist, or via direct siRNA Mdm2 depletion, increased p53 and inhibited viability in CM cell lines. The sensitivity to Nutlin-3 p53 reactivation with concomitant Mdm2 stabilization was higher than that achieved by siRNA, indicative of effects on alternative Mdm2 targets, identified as the cancer-protective IGF-1R. Nutlin-3 treatment increased the association between IGF-1R and β-arrestin1, the adaptor protein that brings Mdm2 to the IGF-1R, initiating receptor degradation in a ligand-dependent manner. Controlled expression of β-arrestin1 augmented inhibitory Nutlin-3 effects on CM survival through enhanced IGF-1R degradation. Yet, the effect of IGF-1R downregulation on cell proliferation is balanced by β-arrestin1-induced p53 inhibition. As mitomycin (MMC) is a well-established adjuvant treatment for CM, and it triggers p53 activation through genotoxic stress, we evaluated how these alternative p53-targeting strategies alter the cancer-relevant bioactivities of CM. In 2D and 3D in vitro models, Nutlin-3 or MMC alone, or in combination, reduces the overall cell tumor growth ~30%, with double treatment inhibition rate only marginally higher than single-drug regimens. However, histopathological evaluation of the 3D models revealed that Nutlin-3 was the most effective, causing necrotic areas inside spheroids and complete loss of nuclear staining for the proliferative marker Ki67. These findings were further validated in vivo; zebrafish xenografts demonstrate that Nutlin-3 alone has higher efficacy in restraining CM tumor cell growth and preventing metastasis. Combined, these results reveal that β-arrestin1 directs Mdm2 toward different substrates, thus balancing IGF-1R pro-tumorigenic and p53-tumor suppressive signals. This study defines a potent dual-hit strategy: simultaneous control of a tumor-promoter (IGF-1R) and tumor-suppressor (p53), which ultimately mitigates recurrent and metastatic potential, thus opening up targeted therapy to CM.