Targeted therapy for malignant ocular melanomas
Introduction
Targeted therapies or molecularly targeted therapy of malignant tumors have become a pillar of the treatment of malignancies in the last decade (1-3). A targeted molecular therapy is a treatment option on the molecular level, blocking the growth of cancer cells by interfering with specific targeted molecules. The molecules are needed for carcinogenesis and growth of the tumors rather than by simply interfering with all rapidly dividing cells in the body as it is achieved by conventional chemotherapy. Besides hormonal therapy and cytotoxic chemotherapy, targeted molecular therapy is one the three types of pharmacotherapy for cancer. Using highly specific molecules affecting the cancer-related processes in a focused manner, side effects caused by systemically applied cancer drugs can be markedly reduced while, simultaneously, the more precise and effective targeting of the tumor cells may improve the outcome. The purpose of this review is to summarize the potentials of a targeted therapy for primary ocular malignant tumors in adults. These tumors mainly include conjunctival melanomas (CMs) and uveal melanomas (UMs), which can be sub-differentiated into melanomas of the ciliary body, the iris and the choroid.
Methods
Search strategy
Using electronic bibliographic databases, PubMed, Embase, and Web of Science were searched for the following keywords with different combinations: “ocular melanoma”, “targeted therapy”, “uveal melanoma”, “conjunctival melanoma”, “mitogen-activated protein kinase (MAPK)”, “PI3K/mTOR”, “BRAF V600E mutation“, “BRAF-mutated conjunctival melanoma”, “pembrolizumab”, “nivolumab”, and “checkpoint immune therapy”. Searches were limited to English and German human studies until May 16th, 2020.
CM
Overview
CMs, malignant melanocytic lesions occurring on the ocular surface, have a low prevalence but showed an increase in their incidence in Europe and the United States in the last decades (4-8). Its prevalence in the United States and Europe was estimated to be approximately 0.5 to 1.0/million (4). After surgical excision CMs frequently recur locally with a frequency estimated to range between 30% to 60% and can lead to lethal metastasis (9-13). Options for systemic therapy of tumor-distant metastases have been limited and lead to death due to metastasis in about 10% to 35% at 10 years follow-up (9-13). CMs share many similarities with cutaneous melanomas including lymphatic metastasis, clinical characteristics, and molecular genetic pattern. As in the case of cutaneous melanomas, the mutation load is high in CMs with about 90,000 mutations in the entire genome, and most mutations in CMs are cytosine to thymine transitions, potentially as a sequel of ultra-violet light-induced damage (14-16). UMs usually show a markedly lower mutational load, also with different mutations involved, and the clinical features of UMs differ profoundly from those of CMs. CMs as well as UMs have been discussed to represent different types of cancer (17). As a corollary, mutations commonly observed in cutaneous melanoma, like V600E in exon 15 of BRAF, Q61L in exon 3 of NRAS or NF1 mutations, have also been detected in CMs. BRAF mutations were detected in 29% to 35%, NRAS mutations in 18%, and NF1 mutations in 33% in CMs (15,18-22).
Clinical findings and procedure
A precursor for CMs is usually a primary acquired melanosis or a conjunctival melanocytic nevus, while only rarely a CM develops de novo (8,23). Clinical features include a brownish pigmented, slightly elevated lesion in the conjunctiva with some hyperemia and dilatation of the feeding conjunctival vessels. Few studies reported also amelanotic CMs (24-27). CMs in their early stage can be misdiagnosed as a therapy-resistant conjunctivitis (28). CMs can grow aggressively and spread superficially on the conjunctiva and extend onto the corneal surface, as well as can grow locally invasively into the deeper tissues. Diagnosis of CMs should include a photographic documentation of the lesion, sonographic examination of the eye and search of metastases (29).
Therapy of CM
The therapy of CMs includes the excisional “no-touch” biopsy of the suspicious lesion, followed by a histopathological examination to assess the nature of the lesion and whether the resection edges are free of tumor cells. An analysis of the serum concentration of lactate dehydrogenase and S100 can also be performed. S100 are CM tumor markers indicating potential CM metastases. A genetic analysis of the samples should search for c-KIT (tyrosine-protein kinase KIT, CD117) and BRAF (proto-oncogene B-Raf), and if not found then NRAS (neuroblastoma RAS) (29,30). Staging using the staging manual of the American Joint Committee of Cancer (AOJCC) and the final diagnosis consists of searching for malignancies in the oropharyngeal compartment and checking of the lymph nodes of the head and neck (29,31). The surgical excision of the primary tumor is followed by adjuvant therapy such as brachytherapy, proton beam radiation, or topical medical therapies such as the application of mitomycin eye drops (32-34).
Targeted therapies for CM
If metastases have developed and with no possibilities for a curative surgical treatment, targeted molecular therapies applying checkpoint-inhibitors such as pembrolizumab or nivolumab come into play. As cancer immunotherapy, checkpoint inhibitor therapy targets immune checkpoints, which are key regulators of the immune system. Activation of these immune checkpoints increases, and inhibition decreases, the immune response to an immunologic stimulus by changing the degree of the T-cell activation or the T-cell effector function. Physiologically, the inhibition of the immune checkpoints serves to prevent the development of auto-aggressive diseases. By stimulating inhibitory immune checkpoint targets, some cancers can protect themselves from an immunological attack by T-cells. A checkpoint therapy blocks inhibitory checkpoints and thus restores the normal function of the immune system. Checkpoint inhibitors target currently approved in medicine include the molecules CTLA4, PD-1, and PD-L1. PD-1 is the transmembrane programmed cell death-1 protein (also called PDCD1 and CD279), which interacts with PD-L1 (PD-1 ligand 1, or CD274). PD-L1 on the cell surface binds to PD1 on an immune cell surface and thus inhibits the immune cell activity. An important function of PD-L1 is the regulation of T-cell activities, so that a cancer-mediated upregulation of PD-L1 on the T-cell surface may inhibit T-cells and prevent them from attacking the cancer cell. Inactivation of PD-1 or PD-L1 by antibodies binding to either of them block their interaction with the T-cell and may thus allow the T-cells to attack the tumor.
Pembrolizumab or nivolumab are currently discussed for the checkpoint-associated therapy of metastasizing CMs, with small case series being published (34-39). However, results of a prospective randomized treatment trial are missing yet. It has remained unclear how far results of phase-III trials on the therapy of cutaneous melanomas using checkpoint inhibitors can be directly transferred on the therapy of CMs (23,40-43).
UMs
Overview
Uveal malignant melanomas, representing about 5% of all malignant melanomas, can be located in the choroid (90%), ciliary body (6%), or iris (4%), and have a mean age-adjusted incidence of 5.1 cases per million per year in Caucasians. They are the most common primary intraocular tumor in adults (44-51). UMs usually manifest in the sixth decade of life. Risk factors include fair skin, blue iris color, inability to tan, ocular or oculodermal melanocytosis, cutaneous or iris or choroidal nevus, and BRCA1-associated protein 1 mutation. Currently, the most widely used first-line treatment options for this malignancy is a local resection, either as a transscleral resection or by an intraocular approach, radiation therapy, and enucleation. Radiation treatment is differentiated into plaque brachytherapy using plaques loaded with iodine-125, ruthenium-106, palladium-103, cobalt-60, and tele-therapy applying proton beam therapy, helium ion therapy, or a stereotactic radiosurgery such as cyber knife, gamma knife, or linear accelerator. Despite all research and improvements in the diagnostic capabilities, the long-term survival rate has remained guarded and mostly unaffected by the therapy. In contrast, the possibilities for a globe and vison salvaging therapy have markedly improved by the increased surgical and radiological treatment options. UMs metastases usually occur in the liver by hematological pathways (44-54).
Despite similarities in their name and stemming from melanocytes, UMs and cutaneous melanomas (and CMs) show profound differences in their risk factors, clinical characteristics and course, metastasizing, genetic pattern and molecular changes, and responses to systemic therapy including targeted molecular therapy. If metastases of UMs have occurred, the life expectancy is markedly reduced, and therapy options are rather limited. It has to be stressed that the characteristics, therapy options and prognosis differ profoundly between CMs and UMs, so that extrapolations from cutaneous melanoma therapies to the treatment of UMs are not possible (44-54).
Genetic variables of UM
Although no evidence-based therapy for metastases of UMs is available yet, prognostication is important for counselling of the patients and planning of follow-up examinations. Besides conventional clinic-pathologic characteristics, including size and location of the tumor and histological tumor cell type, genetic factors are of profound importance for the prognosis. Non-random chromosome aberrations such as monosomy 3 and gain of chromosome 8q are strongly correlated with the risk of metastases, while gain of chromosome 6p is associated with a low risk. In addition, mutations in genes like BAP1, SF3B1 and EIF1AX have been reported to be associated with the prognosis (45-52).
Patients with an UM can have a five-year survival rate of 80%. In dependence of high-risk genetic patterns, such as monosomy 3 and gain of chromosome 8q, the risk for the development of metastasis and the general prognosis can be markedly guarded. Metastases of UM show a high affinity to the liver, as it is commonly the first metastasis detected. Approximately 25% of all UMs develop metastases after 5 years and 34% after 10 years after local treatment. Metastases occur mainly in a hematogenous way, while conjunctival or skin melanomas metastasize rather lymphogenous.
There is no effective adjuvant therapy for metastases of UMs at the moment, while studies of innovative treatment regiments are ongoing, including clinical studies using the chemotherapeutics fotemustine; dendritic cells loaded with autologous tumor RNA to activate CD4- and CD8-T-cell response against tumor antigens; the kinase inhibitor sunitinib alone or in combination with cisplatin/tamoxifen; and anti-receptor tyrosine kinase drugs such as crizotinib (55-61). In contrast to skin melanomas, UMs have not been effectively been treated by targeted molecular therapy (62) (Table 1).
Full table
Conclusions
In conclusion, since CMs show marked similarities in clinical and genetic aspects with cutaneous melanomas, and since, systemic therapies with checkpoint inhibitors have already been established for cutaneous melanomas, the application of checkpoint inhibitors are a treatment option for metastatic CMs. As a corollary, due to differences in clinics and genetics between UMs and CMs or cutaneous melanomas, including the lack of lymphatic vessels in the eye, it has remained elusive whether the available possibilities of molecular targeted therapy are an effective therapy option for metastatic UMs (63,64).
Acknowledgments
Funding: None.
Footnote
Provenance and Peer Review: This article was commissioned by the editorial office, Annals of Eye Science for the series “Eyelid Surgery”. The article has undergone external peer review.
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/aes-20-101). The series “Eyelid Surgery” was commissioned by the editorial office without any funding or sponsorship. LMH served as the unpaid Guest Editor of the series and serves as an unpaid editorial board member of Annals of Eye Science from Dec 2019 to Nov 2021. The authors have no other conflicts of interest to declare.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.
References
- Scott AM, Wolchok JD, Old LJ. Antibody therapy of cancer. Nat Rev Cancer 2012;12:278-287. [Crossref] [PubMed]
- Postow MA, Callahan MK, Wolchok JD. Immune checkpoint blockade in cancer therapy. J Clin Oncol 2015;33:1974-82. [Crossref] [PubMed]
- Vanneman M, Dranoff G. Combining immunotherapy and targeted therapies in cancer treatment. Nat Rev Cancer 2012;12:237-51. [Crossref] [PubMed]
- Tuomaala S, Eskelin S, Tarkkanen A, et al. Population‐based assessment of clinical characteristics predicting outcome of conjunctival melanoma in whites. Invest Ophthalmol Vis Sci 2002;43:3399-408. [PubMed]
- Yu GP, Hu DN, McCormick S, et al. Conjunctival melanoma: is it increasing in the United States? Am J Ophthalmol 2003;135:800-6. [Crossref] [PubMed]
- Triay E, Bergman L, Nilsson B, et al. Time trends in the incidence of conjunctival melanoma in Sweden. Br J Ophthalmol 2009;93:1524-8. [Crossref] [PubMed]
- Seregard S, Kock E. Conjunctival malignant melanoma in Sweden 1969-91. Acta Ophthalmol (Copenh) 1992;70:289-96. [Crossref] [PubMed]
- Heindl LM, Cursiefen C. Bindehautmelanom--eine Systemerkrankung: Neue chirurgische und adjuvante Therapien. Ophthalmologe 2015;112:890-1. [Crossref] [PubMed]
- Shields CL, Shields JA, Gunduz K, et al. Conjunctival melanoma: risk factors for recurrence, exenteration, metastasis, and death in 150 consecutive patients. Arch Ophthalmol 2000;118:1497-1507. [Crossref] [PubMed]
- Missotten GS, Keijser S, De Keizer RJ, et al. Conjunctival melanoma in the Netherlands: a nationwide study. Invest Ophthalmol Vis Sci 2005;46:75-82. [Crossref] [PubMed]
- Paridaens AD, Minassian DC, McCartney AC, et al. Prognostic factors in primary malignant melanoma of the conjunctiva: a clinicopathological study of 256 cases. The Br J Ophthalmol 1994;78:252-9. [Crossref] [PubMed]
- Tuomaala S, Toivonen P, Al-Jamal R, et al. Prognostic significance of histopathology of primary conjunctival melanoma in Caucasians. Curr Eye Res 2007;32:939-52. [Crossref] [PubMed]
- Shields CL, Markowitz JS, Belinsky I, et al. Conjunctival melanoma: outcomes based on tumor origin in 382 consecutive cases. Ophthalmology 2011;118:389-95.e1. [Crossref] [PubMed]
- Rivolta C, Royer-Bertrand B, Rimoldi D, et al. UV light signature in conjunctival melanoma;not only skin should be protected from solar radiation. J Hum Genet 2016;61:361-2. [Crossref] [PubMed]
- Hodis E, Watson IR, Kryukov GV, et al. A landscape of driver mutations in melanoma. Cell 2012;150:251-63. [Crossref] [PubMed]
- Berger MF, Hodis E, Heffernan TP, et al. Melanoma genome sequencing reveals frequent PREX2 mutations. Nature 2012;485:502-6. [Crossref] [PubMed]
- Royer-Bertrand B, Torsello M, Rimoldi D, et al. Comprehensive genetic landscape of uveal melanoma by whole-genome sequencing. Am J Hum Genet 2016;99:1190-8. [Crossref] [PubMed]
- Cancer Genome Atlas Network. Genomic classification of cutaneous melanoma. Cell 2015;161:1681-96. [Crossref] [PubMed]
- Griewank KG, Westekemper H, Murali R, et al. Conjunctival melanomas harbor BRAF and NRAS mutations and copy number changes similar to cutaneous and mucosal melanomas. Clin Cancer Res 2013;19:3143-52. [Crossref] [PubMed]
- Larsen AC, Dahl C, Dahmcke CM, et al. BRAF mutations in conjunctival melanoma: investigation of incidence, clinicopathological features, prognosis and paired premalignant lesions. Acta Ophthalmol 2016;94:463-70. [Crossref] [PubMed]
- Scholz SL, Cosgarea I, Susskind D, et al. NF1 mutations in conjunctival melanoma. Br J Cancer 2018;118:1243-7. [Crossref] [PubMed]
- Swaminathan SS, Field MG, Sant D, et al. Molecular characteristics of conjunctival melanoma using whole-exome sequencing. JAMA Ophthalmol 2017;135:1434-7. [Crossref] [PubMed]
- Shields CL, Chien JL, Surakiatchanukul T, et al. Conjunctival tumors: review of clinical features, risks, biomarkers, and outcomes--The 2017 J. Donald M. Gass Lecture. Asia Pac J Ophthalmol (Phila) 2017;6:109-20. [PubMed]
- Walters AR, Keck KM, Simmons O, et al. Malignant melanoma presenting as amelanotic caruncular lesion in a child. J AAPOS 2017;21:501-3. [Crossref] [PubMed]
- Damani MR, O'Brien JM. Amelanotic conjunctival melanoma. JAMA Ophthalmol 2016;134:e153568. [Crossref] [PubMed]
- Betts RR, Espana EM, Margo CE. Amelanotic Melanoma Arising within conjunctival melanocytic intraepithelial neoplasia sine pigmento. Ophthalmology 2015;122:2178. [Crossref] [PubMed]
- Jay V, Font RL. Conjunctival amelanotic malignant melanoma arising in primary acquired melanosis sine pigmento. Ophthalmology 1998;105:191-4. [Crossref] [PubMed]
- Kopsachilis N, Chatzibougias D, Ziakas N, et al. Chronic red eye due to amelanotic conjuctival melanoma masquerading as pyogenic granuloma. More than meets the eye. Clin Exp Optom 2015;98:283-5. [Crossref] [PubMed]
- Glossmann JP, Skoetz N, Starbatty B, et al. Conjunctival melanoma: Standard operating procedures in diagnosis, treatment and follow-up care. Ophthalmologe 2018;115:489-98. [Crossref] [PubMed]
- Mor JM, Heindl LM. Systemic BRAF/MEK Inhibitors as a Potential Treatment Option in Metastatic Conjunctival Melanoma. Ocul Oncol Pathol 2017;3:133-41. [Crossref] [PubMed]
- Weiling M, Bergua A, Kruse FE, et al. Therapy options for malignant eyelid tumors]. Ophthalmologe 2016;113:1095-108. [Crossref] [PubMed]
- Rokohl AC, Koch KR, Mor JM, et al. Personalized medicine in the treatment of periocular tumors: Targeted treatment and use of immune checkpoint inhibitors. Ophthalmologe 2020;117:521-7. [Crossref] [PubMed]
- Amin MB, Greene FL, Edge SB. editors. AJCC cancer staging manual. 8th edition. Schweiz, Chicago, IL: Springer; AJCC American Joint Committee on Cancer; 2017. Available online: http://www.springer.com/. Assessed 16.5.2020.
- Bosch JJ, Heindl LM. Neue adjuvante Therapien beim okulären Melanom. Klin Monbl Augenheilkd 2017;234:670-3. [Crossref] [PubMed]
- Finger PT, Pavlick AC. Checkpoint inhibition immunotherapy for advanced local and systemic conjunctival melanoma: a clinical case series. J Immunother Cancer 2019;7:83. [Crossref] [PubMed]
- Sagiv O, Thakar SD, Kandl TJ, et al. Immunotherapy With Programmed Cell Death 1 Inhibitors for 5 Patients With Conjunctival Melanoma. JAMA Ophthalmol 2018;136:1236-41. [Crossref] [PubMed]
- Kini A, Fu R, Compton C, et al. Pembrolizumab for recurrent conjunctival melanoma. JAMA Ophthalmol 2017;135:891-2. [Crossref] [PubMed]
- Ford J, Thuro BA, Thakar S, et al. Immune Checkpoint Inhibitors for Treatment of Metastatic Melanoma of the Orbit and Ocular Adnexa. Ophthalmic Plast Reconstr Surg 2017;33:e82-e85. [Crossref] [PubMed]
- Kim JM, Weiss S, Sinard JH, et al. Dabrafenib and trametinib for BRAF-mutated conjunctival melanoma. Ocul Oncol Pathol 2020;6:35-8. [Crossref] [PubMed]
- El Zaoui I, Bucher M, Rimoldi D, et al. Conjunctival melanoma targeted therapy: MAPK and PI3K/mTOR pathways inhibition. Invest Ophthalmol Vis Sci 2019;60:2764-72. [Crossref] [PubMed]
- Cao J, Pontes KC, Heijkants RC, et al. Overexpression of EZH2 in conjunctival melanoma offers a new therapeutic target. J Pathol 2018;245:433-44. [Crossref] [PubMed]
- Hodi FS, O'Day SJ, McDermott DF, et al. Improved survival with ipilimumab in patients with metastatic melanoma. N Engl J Med 2010;363:711-23. [Crossref] [PubMed]
- Postow MA, Chesney J, Pavlick AC, et al. Nivolumab and ipilimumab versus ipilimumab in untreated melanoma. N Engl J Med 2015;372:2006-17. [Crossref] [PubMed]
- Triozzi PL, Eng C, Singh AD. Targeted therapy for uveal melanoma. Cancer Treat Rev 2008;34:247-58. [Crossref] [PubMed]
- Damato B, Eleuteri A, Taktak AF, et al. Estimating prognosis for survival after treatment of choroidal melanoma. Prog Retin Eye Res 2011;30:285-95. [Crossref] [PubMed]
- Harbour JW, Chao DL. A molecular revolution in uveal melanoma: implications for patient care and targeted therapy. Ophthalmology 2014;121:1281-8. [Crossref] [PubMed]
- Field MG, Harbour JW. Recent developments in prognostic and predictive testing in uveal melanoma. Curr Opin Ophthalmol 2014;25:234-9. [Crossref] [PubMed]
- Kaur J, Malik MA, Gulati R, et al. Genetic determinants of uveal melanoma. Tumour Biol 2014;35:11711-7. [Crossref] [PubMed]
- Shields JA, Shields CL. Management of posterior uveal melanoma: past, present, and future: the 2014 Charles L. Schepens lecture. Ophthalmology 2015;122:414-28. [Crossref] [PubMed]
- Chattopadhyay C, Kim DW, Gombos DS, et al. Uveal melanoma: From diagnosis to treatment and the science in between. Cancer 2016;122:2299-312. [Crossref] [PubMed]
- Goh AY, Layton CJ. Evolving systemic targeted therapy strategies in uveal melanoma and implications for ophthalmic management: a review. Clin Exp Ophthalmol 2016;44:509-19. [Crossref] [PubMed]
- Dogrusöz M, Jager MJ. Genetic prognostication in uveal melanoma. Acta Ophthalmol 2018;96:331-47. [Crossref] [PubMed]
- Kalirai H, Dodson A, Faqir S, et al. Lack of BAP1 protein expression in uveal melanoma is associated with increased metastatic risk and has utility in routine prognostic testing. Br J Cancer 2014;111:1373-80. [Crossref] [PubMed]
- Park JJ, Diefenbach RJ, Joshua AM, et al. Oncogenic signaling in uveal melanoma. Pigment Cell Melanoma Res 2018;31:661-72. [Crossref] [PubMed]
- Available online: www.clinicaltrials.gov. Assessed 17.5.2020
- Bailey FP, Clarke K, Kalirai H, et al. Kinome-wide transcriptional profiling of uveal melanoma reveals new vulnerabilities to targeted therapeutics. Pigment Cell Melanoma Res 2018;31:253-66. [Crossref] [PubMed]
- Carvajal RD, Schwartz GK, Tezel T, et al. Metastatic disease from uveal melanoma: treatment options and future prospects. Br J Ophthalmol 2017;101:38-44. [Crossref] [PubMed]
- Diener-West M, Reynolds SM, Agugliaro DJ, et al. Development of metastatic disease after enrollment in the COMS trials for treatment of choroidal melanoma: Collaborative Ocular Melanoma Study Group Report No. 26. Arch Ophthalmol 2005;123:1639-43. [Crossref] [PubMed]
- Moser JC, Pulido JS, Dronca RS, et al. The Mayo Clinic experience with the use of kinase inhibitors, ipilimumab, bevacizumab, and local therapies in the treatment of metastatic uveal melanoma. Melanoma Res 2015;25:59-63. [Crossref] [PubMed]
- Damato B. Does ocular treatment of uveal melanoma influence survival? Br J Cancer 2010;103:285-90. [Crossref] [PubMed]
- Hofmann UB, Kauczok-Vetter CS, Houben R, et al. Overexpression of the KIT/SCF in uveal melanoma does not translate into clinical efficacy of imatinib mesylate. Clin Cancer Res 2009;15:324-9. [Crossref] [PubMed]
- Croce M, Ferrini S, Pfeffer U, et al. Targeted therapy of uveal melanoma: Recent failures and new perspectives. Cancers (Basel) 2019;11:846. [Crossref] [PubMed]
- Heindl LM, Schrödl F, Lütjen-Drecoll E, et al. Ciliary body lymphangiogenesis. Ophthalmology 2013;120:e41-2. [Crossref] [PubMed]
- Schrödl F, Kaser-Eichberger A, Trost A, et al. Lymphatic Markers in the Adult Human Choroid. Invest Ophthalmol Vis Sci 2015;56:7406-16. [Crossref] [PubMed]
Cite this article as: Jonas RA, Rokohl AC, Heindl LM. Targeted therapy for malignant ocular melanomas. Ann Eye Sci 2021;6:7.