Patient survival in uveal melanoma is not affected by oncogenic mutations in GNAQ and GNA11.

BACKGROUND: Mutations in GNAQ and GNA11, encoding the oncogenic G-protein alpha subunit q and 11, respectively, occur frequently in the majority of uveal melanomas. METHODS: Exons 4 and 5 from GNAQ and GNA11 were amplified and sequenced from 92 ciliary body and choroidal melanomas. The mutation status was correlated with disease-free survival (DFS) and other parameters. RESULTS: None of the tumours harboured a GNAQ exon 4 mutation. A GNAQ mutation in exon 5 codon 209 was found in 46 out of 92 (50.0%) of the tumours. Only 1 out of 92 (1.1%) melanomas showed a mutation in GNA11 exon 4 codon 183, whereas 39 out of 92 (42.4%) harboured a mutation in exon 5 of GNA11 codon 209. Six tumours did not show any mutations in exons 4 and 5 of these genes. Univariate analyses showed no correlation between DFS and the mutation status. CONCLUSION: GNAQ and GNA11 mutations are, in equal matter, not associated with patient outcome.

Chromosomal aberrations in iris melanomas.

BACKGROUND: Uveal melanomas can develop in the choroid, ciliary body and iris. In choroidal and ciliary body melanomas, specific chromosomal changes correlate with metastatic disease. Iris melanomas have a better prognosis than choroidal melanomas, and it would be interesting to know if they share chromosomal changes. In addition, iris melanomas might harbour UV-induced mutations of tumour suppressor genes, such as PTEN and CDKN2A. METHODS: Twenty iris melanomas were analysed for chromosome 1p, 3, 6, 8, 9p and 10q abnormalities using fluorescence in situ hybridisation. These results were correlated to clinical follow-up data using statistical analyses. RESULTS: (Partial) loss of chromosome 3 was observed in nine iris melanomas, and gain of 8q was present in seven tumours. Loss of chromosome 9p was demonstrated in seven tumours, but no deletions of the PTEN region on chromosome 10 were found. Three patients died of metastatic disease, and one patient developed liver metastases, but is still alive. Univariate analysis indicated a lower disease-free survival for patients with diffuse growing melanomas (p=0.01), melanomas that lost a copy of chromosome 3 (p=0.03), or invading the ciliary body (p=0.01). In a multivariate analysis, none of the correlations were significant. CONCLUSION: Loss of chromosome 3 as well as loss of chromosomal region 9p21 (that entails tumour suppressor gene CDKN2A) plays a role in iris melanoma. A firm correlation with disease-free survival could not be established, possibly due to the small sample size.

Oncogenic GNAQ mutations are not correlated with disease-free survival in uveal melanoma.

BACKGROUND: Recently, oncogenic G protein alpha subunit q (GNAQ) mutations have been described in about 50% of uveal melanomas and in the blue nevi of the skin. METHODS: GNAQ exon 5 was amplified from 75 ciliary body and choroidal melanoma DNAs and sequenced directly. GNAQ mutation status was correlated with disease-free survival (DFS), as well as other clinical and histopathological factors, and with chromosomal variations detected by FISH and CGH. RESULTS: Of the 75 tumour DNA samples analysed, 40 (53.3%) harboured oncogenic mutations in GNAQ codon 209. Univariate and multivariate analysis showed that GNAQ mutation status was not significantly correlated with DFS. CONCLUSION: The GNAQ mutation status is not suitable to predict DFS. However, the high frequency of GNAQ mutations may render it a promising target for therapeutic intervention.