Abstract
Abstract: :
Cytogenetic analyses of uveal melanomas have shown that chromosome abnormalities, especially those affecting chromosomes 3, 6 and 8, correlate with survival. Purpose: We performed chromosome analyses of uveal melanoma after enucleation in a routine setting. Methods: Cytogenetic analysis was performed on a series of 53 enucleated eyes from patients with a primary uveal melanoma by conventional karyotyping and fluorescence in situ hybridization (FISH). A comparison was made with other known prognostic indicators and survival. Mean follow–up of the patients was 23.9 months. Results: Conventional karyotyping did not succeed in 12 tumours. We did not identify significant differences in tumour characteristics compared to the cases where karyotyping was successful. An option for failure, might be the possibility that the amount of tissue sent in for culture was not sufficient. In the 12 tumours where conventional karyotyping did not succeed, additional FISH analysis for chromosome 3 was possible in four out 12. Monosomy of chromosome 3 and additional copies of 8q were the most common changes: monosomy 3 was found in 17/45 (37.8%) tumours, while 15/41 (36.6%) tumours had additional copies of 8q. Combined alterations of chromosomes 3 and 8 were found in 13/41 (31.7%). Monosomy 3 and i(8q) were both significantly associated with a ciliary body component (P=0.017, P=0.036, respectively) and with largest basal diameter (LBD) ≥12.0 mm (P=0.014, P=0.045). Changes of chromosomes 3 and 8 were analysed for correlation with patient survival. Monosomy of chromosome 3 (P=0.003), additional copies of 8q (P = 0.025) and a LBD ≥12.0 mm (P=0.004) correlated with reduced survival. Histopathological subtype, extrascleral extension, presence of vascular networks, tumour thickness, age, sex and additional alterations of chromosomes 1, 4 and 6 did not have a predictive value for survival in this dataset. Due to the small numbers we could not perform multifactorial analysis. Conclusions: Cytogenetic analysis of uveal melanoma is possible in a routine setting, although the success rate was only 41/53 (77%). The amount of tissue for culture might be responsible why these tumours did not divide and did not produce proper metaphases. In our study, monosomy 3 and a LBD ≥12.0 mm were the best predictors of survival and metastatic disease.
Keywords: melanoma • genetics • oncology