Genetic analyses of uveal melanoma metastases

Purpose To identify genes linked to metastasis development in uveal melanoma (UM), transcriptome analysis linked to comparative genomic hybridization was performed with 63 primary tumors and 115 liver metastasis. 9 primary tumors and their matched metastasis (couples) were also analyzed. A biostatistical approach was used to define the genetic prognosis parameters. BAP-1 mutations reported to be frequently present in class 2 UM were investigated. Results Fifteen percent of the metastases were found disomic for the chromosome 3 (suggesting a class1 profile) and the couples were monosomic for chromosome 3 (suggesting a class2 profile). Examination of the genomic imbalances in couples (all with monosomy 3, suggesting a class2 profile) indicated that no major alterations occurred at the metastatic step. Very few genes (30) were found differentially expressed between the primary tumor and the metastasis after removal of liver expressed genes. Conclusion These results suggest that the events leading to the metastasis spreading are already present in the primary tumor.