Uveal Melanoma Research and Treatment at Mayo Clinic

Mayo Clinic in Rochester, Minnesota, has a long history in the treatment of uveal melanomas. In the early 1980s, Dennis Robertson, MD, was one of the first to use iodine-125 plaques, the form of brachytherapy most commonly used for treatment of uveal melanomas in the United States today. The plaques used in the Collaborative Ocular Melanoma Study (COMS), a multicenter study initiated in 1985 to evaluate therapeutic interventions for patients with choroidal melanoma, used gold shells made at Mayo Clinic. COMS showed that treatment of medium-sized choroidal melanomas (Figure 1) with radioactive plaque brachytherapy was at least 90% successful in local control of the melanoma and had no increase in metastatic risk compared with enucleation. Unfortunately, radiation retinopathy ultimately limits vision in these patients. “The question now, however, is what to do with small, medium, and large melanomas in light of COMS data and new molecular information,” said Jose S. Pulido, MD, of the Department of Ophthalmology. At least 50% of uveal melanomas have a mutation in a protein called GNAQ. Unfortunately, this mutation occurs early on, even in what are considered choroidal nevi. Of more importance is that there appear to be 2 forms of uveal melanomas: • Class 2, a uveal melanoma associated with monosomy of chromosome 3 and with mRNA that confers a high metastatic risk • Class 1, a uveal melanoma with disomy 3 or mRNA testing that has a low metastatic risk “Patients are attuned to these distinctions. Many wish to undergo prognostic testing. It is important to carefully discuss the results and use of the data with patients because at this time there is no prophylactic treatment for clinically undetectable but high-risk uveal melanomas,” according to Dr Pulido. These questions are a focus of intense research at Mayo Clinic and other institutions.