BSLD-06 OUTCOMES IN MELANOMA LEPTOMENINGEAL DISEASE: A RETROSPECTIVE ANALYSIS OF DEMOGRAPHIC AND TREATMENT FACTORS

Abstract Leptomeningeal disease (LMD) is a severe and rapidly fatal complication of melanoma characterized by tumor metastasis to the leptomeninges. Due to its rarity and aggressive nature, research on LMD in metastatic melanoma is limited. This retrospective study examined the characteristics and outcomes of 86 melanoma LMD patients treated at the Moffitt Cancer Center between 2011 and 2020. The study aimed to identify demographic and treatment factors associated with the progression from central nervous system (CNS) metastasis to LMD and factors linked to overall survival (OS) post-LMD diagnosis. The study found that the age of primary melanoma diagnosis was significantly lower in patients who developed LMD compared to the general melanoma population at Moffitt (49 vs 65 years, p < 0.0001). Stereotactic radiosurgery (SRS), immune checkpoint inhibitor (ICI) therapy, and carboplatin and paclitaxel systemic therapy were associated with a delayed progression of CNS metastasis to LMD (p < 0.05). In terms of outcomes, any treatment was associated with longer OS in patients with a Karnofsky Performance Score (KPS) > 60 (10.93 weeks vs 3.07 weeks; p < 0.01). However, treatment did not significantly improve OS for patients with a KPS ≤ 60. Patients treated with ICI therapy (n = 22) showed greater OS compared to those who did not receive ICI therapy (n=64, 12.00 vs 5.87 weeks, respectively; p < 0.01). Furthermore, patients with BRAF-mutant tumors receiving only targeted BRAF/MEKi therapy post-LMD diagnosis (n = 8) had a higher median OS (19.13 weeks) compared to those who did not (n = 29, 3.73 weeks; p < 0.01). In conclusion, this single-center retrospective analysis provides valuable insights into melanoma LMD. Understanding patient characteristics, factors associated with delayed progression, and treatments associated with improved OS are helpful in understanding outcomes in melanoma LMD. Larger, prospective studies are needed to validate these findings.