PATH-97. Retrospective Chart Review of Patients with Leptomeningeal Disease in a Single Institution: Incidence, Treatment, Management, and Failures in a Ten-year Period. What We Missed and How to Move Forward

Abstract BACKGROUND Leptomeningeal disease (LMD) is an aggressive and challenging complication from cancer arising from the invasion of tumor cells to the leptomeninges and cerebrospinal fluid. Melanoma, lung cancer, and breast cancer, are the common etiologies of LMD, although incidence values vary between population studies and LMD can develop from any cancer type. Once thought to be a rare disease, the incidence of LMD is increasing due to improved survival associated with new therapies and improved diagnostic studies. Despite advances in targeted and immunotherapies in the past decade the prognosis of patients with LMD remains grave with overall survival (OS) of weeks to a few months. Herein we will present a retrospective chart review of more than 600 patient with LMD at H. Lee Moffitt Cancer Center & Research Institute. METHODS Patients with LMD have been identified. Eligible patients had histologically or cytologically confirmed diagnosis of a solid tumor, positive CSF cytology and/or clinical signs and symptoms of LMD with characteristic radiographic abnormalities on MRI brain and/or spine. For those who eventually developed LMD, we will use Kaplan-Meier survival curve, log-rank test, univariable, and multivariate Cox proportional hazards regression model to identify factors affecting time from CNS metastasis to LMD and OS. Categorical variables such as patient demographics, baseline characteristics, safety, and treatments will be summarized descriptively using frequencies and percentages. RESULTS More than 600 cases of LMD have been identified and will be included in the analysis. The incidence, primary tumor type, diagnostic studies for diagnosis, treatments pre- and post-diagnosis of LMD, overall survivals, and prognosis will be reported from a single institution. Review is ongoing with expected results in the next few months. CONCLUSIONS Treatments are desperately needed for LMD, as well as finding novel biologically-driven therapies to find cures for this devastating disease. This review will bring insights about changes in incidence of LMD from different cancer types and response to treatments.