Development of metastatic disease after enrollment in the COMS trials for treatment of choroidal melanoma: Collaborative Ocular Melanoma Study Group Report No. 26.

OBJECTIVE: To describe the time between treatment for choroidal melanoma and first diagnosis of metastatic disease, sites of metastasis, treatments for metastasis, and time between diagnosis of metastasis and death.
DESIGN: Prospective, longitudinal follow-up of patients diagnosed with choroidal melanoma who were enrolled in 2 randomized trials conducted by the Collaborative Ocular Melanoma Study Group.
METHODS: Systemic and laboratory evaluations were performed during follow-up according to a standard protocol for 2320 patients enrolled in the Collaborative Ocular Melanoma Study trials without evidence of melanoma metastasis or other primary cancer at baseline.
RESULTS: Seven hundred thirty-nine patients were diagnosed with at least 1 site of metastasis during follow-up after treatment for choroidal melanoma. Five- and 10-year cumulative metastasis rates were 25% (95% confidence interval, 23%-27%) and 34% (95% confidence interval, 32%-37%), respectively. Liver was the most common site (89%). The death rate following the report of melanoma metastasis was 80% at 1 year (95% confidence interval, 77%-83%) and 92% at 2 years (95% confidence interval, 89%-94%). Overall survival after metastasis did not vary by baseline size of primary tumor nor treatment for metastasis (when known). Long-term survival after diagnosis of metastasis was uncommon; only 8 patients survived 5 or more years.
CONCLUSION: Metastasis rate increased significantly with increasing primary tumor dimensions at time of patient enrollment. Prognosis after metastatic disease remains poor. Effective methods are needed to prevent, diagnose, and treat metastasis from choroidal melanoma.