Ocular melanoma-when you have seen one, you have not seen them all: a clinical outcome study from the Surveillance, Epidemiology and End Results (SEER) database (1973-2012).

Background: Ocular melanoma (OM) comprises <5% of all melanomas. Uveal melanoma (UM) is the most common subtype of OM, while conjunctival melanoma (CM) is rare and differs significantly from UM. The purpose of this study is to evaluate a large cohort of OM patients to differentiate demographic, pathologic, and clinical factors between these two neoplasms, which may affect treatment and outcomes.

Methods: The Surveillance, Epidemiology, and End Results database (1973-2012) was used to extract demographic and clinical data on 8,165 OM patients (92.1% UM and 7.9% CM).

Results: Both CM and UM were most prevalent among Caucasian males in the seventh decade of life. UM patients presented more often with localized disease (90.9% vs 81.2, <0.01). Surgery (42.8%), radiation (43.0%), or combined surgery and radiation (7.0%) were used in the treatment of UM, while CM was treated almost exclusively with surgery (88.7%). Mean overall survival was longer (15.4 vs 14.6 years; <0.01) and mortality rates were lower in patients (38.8% vs 46.1%; <0.01) with CM.

Conclusion: Despite presenting with more advanced disease than UM, CM is associated with an increased overall survival. Surgery is the primary therapy for CM, whereas radiotherapy is the primary therapy for UM and is associated with prolonged survival.