Predictors of survival in metastatic melanoma patients with leptomeningeal disease (LMD).

Purpose: Although the survival of most melanoma patients diagnosed with leptomeningeal disease (LMD) is short, some patients can have better outcomes and prolonged survival. A large retrospective cohort of patients was analyzed to identify features associated with survival with LMD from melanoma.

Methods: Clinical characteristics, treatments and survival were collected for melanoma patients diagnosed with LMD from 1999 to 2015. The Kaplan-Meier method was used to estimate overall survival (OS) and Cox proportional hazards regression was used to test statistical significance of associations with survival. Multivariate analysis was performed using Cox proportional regression modeling.

Results: 178 melanoma patients with LMD were identified. Median age at LMD diagnosis was 51 years. Most (n = 153) patients received at least one treatment for LMD, including radiation (n = 98), chemotherapy (n = 89), targeted therapy (n = 60), immunotherapy (n = 12), or intrathecal (IT) therapy (n = 64). Median OS from LMD diagnosis was 3.5 months. One-, two-, and five-year OS rates were 22%, 14%, and 9%, respectively. Factors significantly associated with OS on multivariate analysis included Eastern Cooperative Oncology Group [ECOG] performance status > 0 (HR 2.1, P < 0.0001); neurological symptoms (HR 1.6, P < 0.0001); absent systemic disease (HR 0.4, P < 0.0001); and LMD treatment (HR 0.4, P = 0.0024), targeted therapy (HR 0.6, P = 0.0060), or IT therapy (HR 0.5, P = 0.0019).

Conclusion: Despite their overall poor prognosis a subset of melanoma patients with LMD achieve longer survival. The factors associated with outcomes may be used to guide patient management and to inform the design of future clinical trials for this population.