Iris melanoma: Prognostication for metastasis

Uveal melanoma prognostication studies have mainly included posterior uveal melanomas located in the ciliary body and choroid, often excluding iris melanoma. In this study, we report prognostic status and survival outcomes in a series of 35 patients with biopsy-proven iris melanoma. Fluorescence in situ hybridization was performed in 10 (29%) cases and 2 (5%) underwent multiplex ligation-dependent probe amplification. In total, 9 cases demonstrated disomy 3, 2 cases with monosomy 3 (fluorescence in situ hybridization), and 1 had a technical failure. On gene expression profile testing, 20 of the 23 cases (90%) were gene expression profile class 1A, and the remaining 3 (10%) were class 1B. No patient had a Class 2 status. The median follow-up period was 49 months (mean 59, range 2-156 months). No metastasis was reported during follow-up, and metastasis-free survival was 100%. A review of the published literature revealed 47 cases with high-risk status on molecular prediction, of which only 6 (13%) developed metastasis. Ciliary body involvement was reported in 5 cases and was unknown in 2 cases. We conclude that molecular prognostication of iris melanoma demonstrates low-risk prognostic status in the majority of cases irrespective of the technique used. Even those with high-risk status do not develop metastasis unless the tumor involves the ciliary body.