Clinical features and prognosis of conjunctival melanoma in Japanese patients.

Purpose: To evaluate the clinical features and prognosis of conjunctival melanoma in Japanese patients.

Study design: Retrospective observational case series.

Methods: Twenty patients (8 men and 12 women) diagnosed with conjunctival melanoma at a singlehospital between 2003 and 2017 were analyzed. Data on clinical presentation, sex, age, the affected eye, tumor location, tumor origin, tumor stage according to the American Joint Committee on Cancer staging system (eighth edition), treatment, outcomes, local recurrence, metastasis, and survival were extracted from the patients' medical records and reviewed.

Results: The mean age at diagnosis was 64.2 ± 14.8 years. Tumor locations at the first examination included the bulbar conjunctiva (n = 19), plica (n = 13), and fornix (n = 12). The tumor stage was T1 in 5 cases (25%), T2 in 12 cases (60%), T3 in 3 cases (15%), and T4 in none. The mean follow-up duration was 91.7 ± 46.0 months. The local recurrence rates at 1, 5, and 10 years were 5.0%, 18.8%, and 31.5%, respectively, whilst the metastasis rates were 5.0%, 25.6%, and 32.4%, respectively. Four of the 6 patients who experienced metastasis died; duration from metastasis to death was 17.5 months (range, 7-25). The 5-year survival rate for conjunctival melanoma was 78.8%. Tumor thickness was significantly associated with survival duration on univariate Cox regression analyses.

Conclusion: The mortality rate for conjunctival melanoma in the Japanese population was lower and higher than that reported in the Chinese and United States populations, respectively. Tumor thickness was a prognostic factor for survival in patients with conjunctival melanoma.