Unexpectedly Low Rate of Metastasis and Death Among Patients Treated for Uveal Melanoma with Brachytherapy, Vitrectomy, and Silicone Oil

<b>Introduction:</b> Historically, approximately 30-32% of uveal melanoma patients develop metastases and die within 5 years. Larger tumor dimensions and monosomy 3 and/or Class 2 gene expression profile of the tumor are associated with an increased risk of metastasis. We evaluated the performance of these prognostic markers in patients undergoing surveillance in a community medical oncology practice. <b>Methods:</b> Uveal melanoma patients treated by a single vitreoretinal surgical oncologist and monitored by a single medical oncologist were identified via a clinical database search for analysis. Specified prognostic markers were evaluated for sensitivity, specificity, positive and negative predictive value, as well as prognostic accuracy. <b>Results:</b> We identified 37 uveal melanoma patients, followed for a median of 4.0 ± 3.7 years. Twenty-seven (73%) patients underwent plaque brachytherapy with vitrectomy and silicone oil for radiation attenuation; seven (19%) patients underwent brachytherapy alone; three (8%) had enucleation. There were no intraocular treatment failures. Six (16.2%) patients developed metastasis, and only one patient died of metastatic disease. Disomy 3 and Class 1 accurately predicted a low risk for metastasis (>90% negative predictive value). However, monosomy 3 and Class 2 had a low positive predictive value and prognostic accuracy in "high-risk" patients. <b>Conclusions:</b> In this single-center cohort, we observed an unexpectedly low rate of 5-year metastasis. AJCC stage correlated poorly with metastasis or survival. Molecular prognostic results of Disomy 3 and Class 1 gene expression profile accurately predicted a "low" risk for metastasis (>90% negative predictive value). Further evaluation of these unique surgical techniques needs to be carried out.