Baseline characteristics, hospital outcomes, and palliative care utilization in leptomeningeal disease: A nationwide analysis.

e14004 Background: Leptomeningeal metastasis (LM) is a rare but devastating manifestation of cancer metastasis. Most solid tumors are known to cause LM, but the most common etiology is breast cancer and lung cancer. The incidence of LM has been increasing due to increased survival rates secondary to the improved systemic cancer treatment. Here we aim to explore the baseline characteristics, epidemiologic differences, palliative care utilization. and hospital outcomes of LM. Methods: Nationwide Inpatient Sample (NIS) database 2016-2019 was queried to determine adult hospitalized patients with LM and relevant cancers by using ICD-10 codes. We studied the racial and socioeconomic differences, palliative care utilization, length of stay (LOS), total hospital charges (THC), and all-cause mortality in cancer patients with and without LM. Multivariate logistic regression analysis was conducted to adjust for confounders. Results: There were 15,325 admissions with LM, 20% had lung cancer (LC) and 20.4% had breast cancer (BC). The prevalence of LM was 1.9% and 0.5%, respectively, in LC and BC patients. LM patients were younger (LC 63 vs 69; BC 56 vs 64 p<0.001), more likely to be non-White, and more likely to have private insurance (37% vs. 19%, p<0.001). LM admissions had significantly increased LOS and higher THC compared to other cohorts. BC or LC with LM was associated with significantly increased Palliative care consult rate ( LC 31% vs 16%; BC 29% vs 10% p<0.001) compared to BC and LC without LM. Palliative care use was more common in the African American race. The all-cause mortality rate in hospitalizations with LM was increased compared to cancer without LM (LC 11% vs 8.6% p=0.008 aOR 1.41; BC 12.8% vs 4.5% p<0.001 aOR 3.39). The white race (OR 0.6, p<0.001) and Medicare (OR 0.58 p<0.001) were associated with lower odds of mortality, while the Hispanic race (OR 1.43, p=0.042) and Medicaid (OR 1.39, p=0.041) were associated with higher odds of mortality among LM hospitalizations. Conclusions: While actionable mutations and targeted therapies are developing rapidly, therapeutic options for LM remain limited, with a median survival of 4-5 months. Palliative care remains essential for a better quality of life; hence further studies should be conducted to improve the utilization of palliative care and investigate racial and economic disparities in the utilization of such.