Gain of chromosome 8q and high expression of EZH2 may predict poor prognosis in Chinese patients with uveal melanoma.

PURPOSE: To explore risk factors predicting poor prognosis of uveal melanoma in a Chinese population, with specific emphasis on monosomy 3, 8q gain, and EZH2 staining.

METHODS

Eighty-nine patients with uveal melanoma from 2012 to 2021 were reviewed. Clinical and pathological records were collected and analyzed. Immunohistochemical staining of EZH2, monosomy 3 and 8q gain were respectively conducted in 45, 54, and 57 cases. Survival was evaluated by Kaplan-Meier analysis and log-rank test. Cox proportional hazard regressions were employed to predict risk factors of distant metastasis.

RESULTS

The median follow-up was 44 months. Altogether, 16 % of patients developed distant metastases and died from disease-related causes. Disease-specific survival at one and three years was 96.6 % and 88.4 % while distant metastasis rates were 7.9 % and 12 %. Univariate Cox regression analysis revealed that age (HR: 1.04), tumor largest basal diameter (HR: 1.21), tumor thickness (HR: 1.21), ciliary body involvement (HR: 3.50), AJCC stage (HR: 5.68), epithelioid cell type (HR: 7.71), 8q gain (HR: 7.48), and high expression of EZH2 (HR: 6.09) were associated with distant metastasis. 8q gain was associated with epithelioid cell type and thicker tumor while EZH2 was correlated with epithelioid cell type. Monosomy 3 lacked a significant correlation with other factors.

CONCLUSION

EZH2 and 8q gain could be taken into consideration when calculating poor prognosis in Chinese patients with uveal melanoma. Monosomy 3 showed no significance in distant metastasis, but this may be due to a small sample size.