The prognostic value of extraocular extension in relation to monosomy 3 and gain of chromosome 8q in uveal melanoma

PURPOSE: To identify the prognostic value of extraocular extension in enucleated uveal melanoma (UM) patients and to correlate extraocular extension to chromosomal aberrations, metastasis-free survival (MFS), and clinico-histopathological risk factors.

METHODS: Retrospective study of patients with UM treated with enucleation between 1987 and 2011. Melanoma-related metastasis and death were recorded. Statistical analysis (log-rank test or Cox regression analysis) was performed to correlate MFS with tumor characteristics, extraocular extension, episcleral diameter of the extraocular extension, cell type, extracellular matrix patterns, inflammation, loss of chromosome 3, and gain of chromosome 8q.

RESULTS: In 43 (12%) of 357 patients, extraocular extension was observed. In this subset of patients, we noted a reduced survival of 70 months (105.5 months, P = 0.010) compared with patients without extraocular extension (175.8 months). Patients with gain of chromosomal region 8q in UM with extraocular extension had an increased risk of metastatic disease (P < 0.001). In multivariate Cox proportional hazard analysis, largest basal tumor diameter (P = 0.001), extracellular matrix patterns (P = 0.009), episcleral diameter of the extraocular extension (P = 0.016), loss of chromosome 3 (P < 0.001), and gain of 8q (P < 0.001) were independent predictors for MFS.

CONCLUSIONS: Larger episcleral diameter of the extraocular extension and additional gain of chromosome 8q in extraocular extension UM correlates to a worse prognosis. MFS is significantly reduced in UM with a large basal tumor diameter, extracellular matrix patterns, loss of chromosome 3, and gain of chromosome 8q.