NOV 05, 2007
Comprehensive Ophthalmology, Retina/Vitreous
A group of distinguished investigators has reported in Ophthalmology seven years of experience with routine cytogenetic analysis of uveal melanoma in a clinical environment
Cytogenetics is at the forefront of managing melanomas, and this is the largest published series on the prognostic significance of chromosomes 3 and 8 abnormalities in uveal melanoma. The value of this investigation is enhanced by the fact that the cytogenetic studies were performed as part of routine clinical practice and not under artificial research conditions.
They conclude that cytogenetic analysis of chromosomes 3 and 8 enhances prediction of disease-specific mortality after treatment of uveal melanoma but must be interpreted together with tumor diameter and cell type. These findings suggest that cytogenetic studies should be considered as part of the histopathologic evaluation for all choroidal melanomas.
Their non-randomized case series included 356 patients. Biopsies were performed as part of the work-up to establish a diagnosis. Fine needle aspiration biopsy and then PPVx 25 gauge (after Sept 2004) were used to obtain tissue.
Cytogenetic studies showed monosomy 3 in 168 tumors (47.2%) and chromosome 8 gains in 132 tumors (37.1%), with 3 copies of chromosome 8 in 102 tumors (28.7%), 4 in 21 (5.9%), 5 in 5 (1.4%), 6 in 3 (0.8%), and 7 in 1 tumor (0.3%). Multivariate analysis showed the most significant prognostic factors were largest basal tumor diameter (P<0.001), epithelioid cells (P = 0.004), and monosomy 3 (P<0.001). Five-year disease-specific mortality rates were 6% in the absence of chromosomal abnormality, 31% with only chromosome 8 gain, 40% with only monosomy 3, and 66% with abnormality of both chromosomes 3 and 8 (log-rank; P<0.001). There was no interaction between monosomy 3 and chromosome 8 gain in their associations with the other variables.