Impact of Tumor Pigmentation in 6934 Patients with Uveal Melanoma at a Single Center

To evaluate clinical features and outcomes associated with degree of tumor pigmentation in patients with uveal melanoma (UM) of the choroid and ciliary body.

Retrospective observational study.

Six thousand nine hundred thirty-four consecutive patients with choroidal or ciliary body melanoma between 1971 and 2007 from a single ocular oncology center.

Data on patient demographics, tumor characteristics, treatment approach, and clinical outcomes were collected. Comparisons between pigmented (>80% pigmentation by surface area), partially pigmented (20%-80%), and nonpigmented tumors (<20%) were performed using relevant hypothesis testing. Survival analyses for metastasis and melanoma-related death were conducted using the Kaplan-Meier method with log-rank tests for univariate comparisons. A multivariate Cox regression analysis was performed to assess the independent effects of multiple covariates on time-to-metastasis.

Extraocular extension, ocular melanocytosis, time to tumor recurrence, tumor location, and melanoma-related metastasis and death.

There were 6934 eyes with UM and the degree of tumor pigmentation was classified as pigmented (n = 3762; 54%), partially pigmented (n = 2115; 31%), or nonpigmented (n = 1057; 15%). Pigmented UM was associated with extraocular extension (P < 0.001), ocular melanocytosis (P = 0.003), earlier tumor recurrence (P < 0.001), and more anterior tumor epicenter location (ciliary body, and equator to ora serrata) (P < 0.001). Pigmented UMs also exhibited the highest 10-year metastasis rate at 26%, compared with 19% for partially pigmented UMs and 16% for nonpigmented UMs (P < 0.001). Kaplan-Meier survival curves demonstrated differences among the tumor pigmentation groups for melanoma-related metastasis (P < 0.001) and melanoma-related death (P < 0.001). Multivariate Cox regression analysis for melanoma-related metastasis showed that pigmented UMs had a 29% higher relative risk of developing metastasis compared with partially pigmented UMs (P = 0.002) and a 54% higher relative risk of developing metastasis compared with nonpigmented UMs (P < 0.001).

Pigmented choroidal and ciliary body melanoma is more often associated with ocular melanocytosis, extraocular extension, anterior tumor epicenter, and earlier tumor recurrence. We also revealed that patients with pigmented UMs demonstrate a higher 10-year rate of metastatic disease and have decreased metastatic survival relative to partially pigmented and nonpigmented UMs.

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.