Primary Orbital Melanoma: An Investigation of a Rare Malignancy Using the National Cancer Database

Objectives: Primary orbital melanoma (POM) is a rare disease with limited data on survival and best treatment practices. Here we utilize the National Cancer Database (NCDB) to determine the overall survival (OS) and covariates that influence mortality.

Study design: Retrospective cohort study.

Methods: All patients diagnosed with POM from 2004 to 2016 were identified in the NCDB. Patient and oncologic data were analyzed using the Kaplan-Meier method and multivariate models for the primary outcome of OS.

Results: A total of 129 patients were identified. Median OS was 36.9 months (95% confidence interval [CI] 24.1-78.7 months) with mean 5-year survival of 42.0% (CI 33.2%-53.2%). Treatments received included surgery alone (43.4%), radiation alone (23.3%), and surgery followed by radiation (20.2%). The multivariate model demonstrated an increased risk of death associated with age over 80 years (hazard ratio [HR] 3.41, CI 1.31-8.86, P = .012), a Charlson-Deyo comorbidity score of 2 or greater (HR 5.30, CI 1.87-15.03, P = .002), and no treatment (HR 2.28, CI 1.03-5.06, P = .042). For every 1 cm increase in tumor size, there was an increased risk of death (HR 1.06, CI 1.00-1.13, P = .039). When compared to surgery alone, no other treatment modality had an effect on OS.

Conclusions: This study leveraged multiyear data from the NCDB to provide prognostic and demographic information on the largest known cohort of POM cases. Increased age, increased comorbidities, not receiving treatment, and larger tumor size were associated with increased mortality. There was no clear survival advantage for specific treatments.

Level of evidence: 4 Laryngoscope, 131:1790-1797, 2021.