Heterogeneity of GNAQ/11 mutation inversely correlates with the metastatic rate in uveal melanoma.

PURPOSE: To determine whether the GNAQ/11 mutation correlated with the outcome of patients with uveal melanoma (UM) when genetic heterogeneity was considered.

METHODS

We performed a retrospective study of sixty-seven patients with UM. The heterogeneity of GNAQ/11 was examined by using droplet digital PCR. The correlation between metastasis and heterogeneity of the GNAQ/11 mutation was analysed. Disease free survival curves were constructed using the Kaplan-Meier method, and the Wilcoxon log-rank test was used to compare the curves.

RESULTS

The GNAQ/11 mutation ratio was varied between each case. Among these patients, 28.35% of them harboured homogeneous mutation of GNAQ/11, 62.69% present heterogeneous mutation and 8.96% didn't present either GNAQ or GNA11 mutation. The tumour with heterogeneous mutation of GNAQ/11 has a higher metastatic rate than that with homogeneous mutation (13/29 vs 1/18, p=0.027). In Kaplan-Meier analysis, metastasis-free survival was not significantly associated with either homogeneous or heterogeneous mutation of GNAQ/11.

CONCLUSION

The mutation ratio of GNAQ/11 in UM was quite variable. The tumour with heterogeneous mutation of GNAQ/11 is more likely to develop a poor prognosis than that with homogeneous mutation of GNAQ/11.