Prognostic factors for conjunctival melanoma: a study in ethnic Chinese patients

In patients with conjunctival melanomas, surgery is the first choice of treatment, but no standard adjuvant therapy has been established. In this study, we evaluated prognostic factors for conjunctival melanoma in ethnic Chinese patients.

Demographic data, known (published) prognostic factors, BRAF and KIT gene mutations, treatment strategies and outcomes were reviewed in 53 patients with pathologically confirmed conjunctival melanomas. Univariate and multivariate analyses of factors associated with survival were performed by the Kaplan-Meier method and a Cox proportional hazard model, respectively.

Univariate analyses for 50 patients in whom data were available showed that a higher T stage (p=0.041), greater tumour thickness (p=0.006), local resection (p=0.033) and no adjuvant therapy (p=0.006) were associated with a worse recurrence-free survival (RFS) and metastasis-free survival (MFS). Patients with more involved quadrants also had worse MFS (p=0.039), while a higher T stage (p<0.001), local resection (p=0.008), and no adjuvant therapy (p=0.028) were associated with worse overall survival (OS). However, BRAF or KIT mutations showed no correlations with RFS, MFS or OS. Patients who received high-dose interferon (HDI) adjuvant therapy had a better RFS (p=0.004), MFS (p=0.001) and OS (p=0.005) than those who did not. Multivariate analysis showed that adjuvant therapy and tumour thickness were significant predictive factors for RFS, and the T stage was a significant predictive factor for OS.

Adjuvant therapy and tumour thickness are significantly associated with RFS and T stage is a significant predictor of OS in Chinese patients with conjunctival melanomas. Patients may benefit from adjuvant therapy with HDI.