Determinants of Long-Term Survival in Metastatic Choroidal and Ciliary Body Melanoma

Abstract

To build and validate a prognostic model that predicts long-term overall survival (OS) in metastatic choroidal and ciliary body melanoma (CCBM) to facilitate patient counseling and planning, reporting, and interpreting clinical trials. Retrospective cohort study with validation. We analyzed predictors of intermediate (IMT; 25-<42 months) and long-term (LT; ≥42 months) OS in a Finnish nationwide cohort of 330 patients with metastatic CCBM. Short-term (<25 months), IMT, and LT survival were compared with pairwise and ordinal logistic regression. A single-center cohort of 259 patients from Italy was used for validation. Models were compared with a deviance test. Median OS was 12 and 17 months in the building and validation datasets, respectively; 40 (12%) and 31 (9%) compared with 44 (17%) and 32 (12%) patients were IMT and LT survivors, respectively. Alkaline phosphatase or lactate dehydrogenase level never exceeded 2 times the upper normal limit (UNL) in either LT cohort. Conditional to both being ≤2 times the UNL, distant metastasis-free interval (DMFI) >42 months (odds ratio [OR] 4.09-4.64; P < .001) paired with age <60 years (OR 3.23; P=.002), having no symptoms (OR 4.19; P=.005), and the largest diameter of the largest metastasis <30 mm (Tumor, Node, Metastasis stage M1a; OR 3.05; P=.001) independently predicted higher odds of surviving longer (IMT or LT) without model preference. These results were confirmed in the validation dataset. Alkaline phosphatase or lactate dehydrogenase >2 times the UNL essentially precluded LT survival. The most robust predictor otherwise was DMFI >42 months, followed by age <60 years, absence of symptoms, and Tumor, Node, Metastasis stage M1a.