8q Gain Has No Additional Predictive Value in SF3B1 MUT Uveal Melanoma but Is Predictive for a Worse Prognosis in Patients with BAP1 MUT Uveal Melanoma

Gain of chromosome 8q has been associated with poor prognosis in uveal melanoma (UM), and an increase in the absolute number of 8q-copies correlated with an even shorter survival. Splicing factor 3b subunit 1 ( )-mutated ( ) tumors display structural chromosomal anomalies and frequently show a partial gain of chromosome 8qter. A recent subset of UM with early-onset metastases has been identified, prompting the investigation of the relationship between survival, 8q gain, and UM. Retrospective cohort study. Patients diagnosed with UM who underwent enucleation or received a biopsy at the Erasmus MC Cancer Institute or the Rotterdam Eye Hospital, The Netherlands were included. Fifty-nine patients with tumors and 211 patients with BRCA1 associated protein 1 ( )-mutated ( ) tumors were included in this study. Copy number status and gene expression were assessed using either a single nucleotide polymorphism array, fluorescence in situ hybridization, and karyotyping, or a combination of these techniques. Disease-free survival was determined and a cut-off of 60 months was used to define early-onset metastatic disease. Disease-free survival. Forty-eight patients with UM (81%) had chromosome 8q gain (3 copies, 78%; 4 copies, 22%). Kaplan-Meier analysis of UM did not indicate a difference in survival in patients with or without gain of 8q ( = 0.99). Furthermore, the number of 8q copies was not associated with survival when comparing early ( = 0.97) versus late ( = 0.23) metastases group. In contrast, the presence of 8q gain (86%) was correlated with a decreased survival in UM ( = 0.013). We did not find a correlation between 8q gain and early-onset metastasis in tumors. Gain of 8q has no additional predictive value in tumors. In contrast, 8q gain is predictive of a worse prognosis in patients with tumors. Thus, gain of chromosome 8q has additional predictive value for tumors, but not for tumors. The author(s) have no proprietary or commercial interest in any materials discussed in this article.