Trends in incidence, survival, and management of uveal melanoma: a population-based study of 7,516 patients from the Surveillance, Epidemiology, and End Results database (1973-2012).

Introduction: Uveal melanoma (UM) is the most common primary intraocular malignancy, despite comprising <5% of all melanomas. To date, relatively few case series of UM have been published. Moreover, the factors influencing survival remain largely unknown. This study sought to analyze the impact of demographics, histology, clinical presentation, and treatments on the clinical outcomes of UM in a large modern nationwide patient cohort.

Methods: Demographics and clinical data were abstracted on 277,120 histologically confirmed melanoma patients from the Surveillance, Epidemiology, and End Results database between 1973 and 2012.

Results: A total of 7,516 cases of UM represented 3.2% of all recorded cases of melanoma. The mean age-adjusted incidence was 5.1 per million (95% CI 4.2-6.1) and was higher in males (5.9, CI =4.4-7.6) compared to females (4.5, CI =3.3-5.8), <0.001. UM occurred most commonly in the sixth decade of life (61.4±15) and among Caucasians (94.7%). A total of 52.3% of cases were reported in the Western US (35.7% in California). The initial diagnoses in 65.2% of cases were by histopathology, followed by clinical diagnosis (18.8%) and radiographic imaging (16.0%). The percentage of UM cases managed by surgery alone decreased by 69.4% between the 1973-1977 and 2006-2012 time periods, concomitant with a 62% increase in primary radiotherapy, <0.001. The UM mean overall and cancer-specific 5-year relative survival rates were 79.8%±5.8% and 76%±5.3%, respectively. The mean 5-year cancer-specific survival rate (76%) remained stable during the study period between 1973 and 2012. The mean survival for patients treated with primary radiotherapy was significantly improved compared to those treated with surgery alone (15.4±0.4 vs 13.6±0.3, <0.001). Multivariate analysis identified male sex (odds ratio [OR] 1.1, CI =1.0-1.3), age >50 years (OR 4.0, CI =3.4-4.6), distant metastases (OR 8.6, CI =4.7-15), and primary surgical treatment (OR 2.6, CI =2.0-3.3) as independently associated with increased mortality, <0.005. Conversely, patients identified as Hispanic (OR 0.6, CI =0.5-0.8) and patients receiving radiation treatment (OR 0.5, CI =0.4-0.7) were independently associated with reduced mortality, <0.005.

Conclusion: UM remains a rare form of melanoma that occurs primarily in Caucasian patients older than 50 years. More than two-thirds of UM patients are curatively treated with primary radiotherapy as opposed to surgery, which has resulted in a significant improvement in both overall survival and cancer-specific survival. Despite this shift in management strategy, the mean 5-year cancer-specific survival rate remained relatively unchanged during the study period. Male sex, older age, distant disease, and primary surgical therapy rather than radiotherapy are associated with an increased risk of mortality.