F-41 | Types of Thromboembolic Events and their Outcomes in Breast Cancer Patients- A Propensity Matched Nationwide Analysis

Venous thromboembolic events (VTE) are a major cause of morbidity and mortality in patients with active malignancy. We aim to investigate the outcome and incidence of acute DVT and PE in breast cancer compared to all other malignancies. The National Readmission Database (2016-2020) was queried to identify all-cause admissions for patients with active breast cancer (all types). A Propensity Score Matching (PSM) model, matched patients with breast cancer to patients with other active malignancies. Pearson's x2 test was applied to the PSM-matched cohorts to compare outcomes. Among 3. 7 million all-cause hospitalizations of breast cancer patients, about 3. 6% suffered a VTE. The majority had acute DVT (1. 6%), followed by acute PE (1. 5%) and DVT with PE (0. 6%). After propensity-matching & multivariate analysis, patients with breast cancer have a lower incidence of acute DVT (2. 2% vs 2. 9%, aOR: 0. 76), acute PE (2. 2% vs 2. 3%, aOR: 0. 96) & DVT with PE (0. 9% vs 1. 1%, aOR: 0. 78) p <0. 001 as compared to other patients with any type of active cancer. However, VTEs are associated with worse mortality. Among different VTEs, the mortality was highest for acute PE (aOR: 2. 15), followed by DVT (aOR: 1. 69) & DVT with PE (aOR: 1. 58) p <0. 001. Resource utilization was higher in breast cancers complicated by VTE, with patients suffering a DVT having the highest LOS (6 vs 3 days) & total cost of hospitalization (16, 556 vs 12, 548) p<0. 001 followed by DVT with PE and PE only (p<0. 05). Interestingly, patients with DVT have higher readmission rates as compared to PE at 90 days (32. 6% vs 28. 5%, p <0. 001). Hospitalization in breast cancer patients was less frequently complicated by venous thromboembolism as compared to other malignancies. The mortality was highest for PE in this cohort, while healthcare-related burden and readmission rates were higher for DVT.