Purpose: To evaluate the prognosis in Chinese patients with conjunctival melanoma and determine its predictors. Further, to explore the racial differences in clinical characteristics and outcomes between Chinese and Caucasian patients.
Methods: This cohort study included 57 eyes of 57 consecutive patients with pathologically verified conjunctival melanoma between 1996 and 2016. Medical records were reviewed for factors associated with the local recurrence, metastasis, and tumor-related mortality. All eligible patients were followed up for these three outcome measures. The demographic data, clinical characteristics, and outcomes were compared between Chinese and Caucasian patients.
Results: The mean follow-up period was 52.2 ± 49.4 months. Among the total 57 patients, 29 (51%) patients experienced local recurrence. The 1-, 5-, and 10-year recurrence rate was 31.0%, 59.7%, and 66.4%, respectively. Treatment complications detected in the follow-up included dry eye (32, 56.1%), irregular eyelid margin (25, 43.9%), eyelid retraction (18, 31.6%), blepharoptosis (9, 15.8%), mixed pigmentation of the tarsus reconstructed by mucosal membrane graft, corneal opacities (6, 10.5%), and symblepharon (2, 3.5%). Twenty (35%) patients developed metastasis. The 1-, 5-, and 10-year metastasis rate was 16.7%, 38.7%, and 50.9%, respectively. Fourteen (25%) patients died of conjunctival melanoma, with a median survival time of 24 months. The 1-, 5-, and 10-year tumor-related mortality was 3.8%, 30.5%, and 37.4%, respectively. Tumor hemorrhage is an independent risk factor for tumor-related death (hazard ratio [HR]: 18.81, P = 0.01) and metastasis (HR: 4.57, P = 0.02). Significant differences were noted between Chinese and Caucasians patients from America, Germany, and England in demographics, clinical characteristics, and outcomes. Compared to Caucasians, Chinese patients tended to have more male cases (P < 0.01) and to be younger (P = 0.03). At initial presentation, more Chinese patients had de novo tumor origin (P < 0.01), epithelioid cell type (P < 0.01), nonbulbar tumor location (P < 0.01), greater basal diameter (P = 0.04), multifocal tumor (P < 0.01), feeder vessels (P < 0.01), eyelid (P < 0.01) and orbit involvement (P < 0.01), and advanced T stages (P < 0.01). Over a similar follow-up period with Caucasians patients (52.2 vs. 52 months, P = 0.97), a significantly larger proportion of Chinese patients exhibited eyelid invasion (P = 0.04) and orbital invasion (P < 0.01) at follow-up, local recurrence (P < 0.01), metastasis (P < 0.01), and tumor-related death (P < 0.01).
Conclusions: Conjunctival melanoma is a rare malignancy with great potential for mortality in Chinese. Special attention should be paid to patients with tumor hemorrhage. Compared to Caucasians, Chinese patients exhibit more aggressive clinical signs with compromised prognosis.