Survival Outcomes of Uveal Melanoma Involving the Anterior Chamber of the Eye: A National Retrospective Cohort Study: Denmark, 1943-2022.

Purpose: To investigate survival patterns of uveal melanomas involving the anterior chamber by tumor extension and primary tumor location.

Design: Retrospective cohort study.

Participants: Patients diagnosed with uveal melanoma in Denmark between 1943 and 2022 were identified, and cases were reviewed. Patients with tumors involving the anterior chamber were included and categorized into 4 groups based on tumor anatomic extent and configuration: (1) isolated iris melanomas, (2) iris and ciliary body tumors, (3) ring melanomas, and (4) tumors involving iris, ciliary body, and choroid.

Methods: Patient data were analyzed using survival analysis techniques. Cumulative incidences of metastatic death were calculated using competing risk methods. Cause-specific hazard ratios (HRs) were estimated using Cox proportional hazards regression. Restricted mean survival time and life-years lost were calculated at the 10-year and 20-year follow-ups.

Main outcome measures: Primary outcome was mortality resulting from uveal melanoma metastasis. Secondary measures included cumulative incidences, cause-specific HR, restricted mean survival time, and life-years lost at 10 and 20 years.

Results: Among 3859 eligible patients, 789 patients had tumors with anterior chamber involvement, of which 786 patients were included in the analysis. The 20-year cumulative incidence of metastatic death was 0.7% for isolated iris melanomas, 10% for tumors involving the iris and ciliary body, 32% for ring melanomas, and 68% for tumors involving all 3 uveal structures. Compared with tumors involving the iris and ciliary body, the HR was 0.05 (Confidence interval [CI] 0.01-0.4) for isolated iris melanomas, 5.0 (CI, 2.5-10.3) for ring melanomas, and 15.3 (CI, 8.3-28.3) for tumors involving all uveal structures. Ring melanomas significantly worsened survival in iris melanomas (HR, 51.7, CI, 11.2- 239.3) but not in ciliary body melanomas. Among tumors involving both the iris and ciliary body, those primarily located in the ciliary body showed substantially higher mortality (HR, 19.1, CI, 2.4-149.5).

Conclusions: Survival outcomes of uveal melanomas involving the anterior chamber varies by anatomic extension. Ring melanomas resemble ciliary body melanomas in survival outcomes and drive poor prognosis in iris melanomas. Excluding ring melanomas, tumors primarily located in the iris have very low metastatic potential, even with ciliary body involvement. Tumors involving all 3 uveal structures are associated with extremely poor outcomes.

Financial disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.