Clinical presentation, pathological features and natural course of metastatic uveal melanoma, an orphan and commonly fatal disease.

Background: Uveal melanoma (UM) is a rare disease characterized by an unpredictable course and a variable outcome. We assessed the natural course of patients with metastatic uveal melanoma (MUM).

Methods: Data from 76 patients with MUM who were treated in Leuven between 1957 and 2008 were examined retrospectively. Statistical analysis involved the nonparametric, Kaplan-Meier and log rank tests.

Results: The median age at diagnosis of UM was 58 years (range 30-94). Synchronous metastases were found in 9% of the cases; all other patients had metachronous disease after a median interval of 40 months (range 7-420). Statistical analysis failed to identify factors related to the time until metastatic spread with the exception of a significant negative correlation with age at UM diagnosis (Spearman: ρ = -0.4, p < 0.001). The most frequent metastatic site was the liver (in 96% of the patients). The median time from diagnosis of UM until death was 47 months (range 2-236) and only 5 months in patients with metastatic disease (range 1-128).

Conclusions: MUM is an orphan disease. Advances in MUM can only be achieved by the networking of sites interested in this rare tumor type, with systematic collection of data and tumor tissue for improving our understanding of the molecular biology of this disease.