Investigating the outcome of vascular emboli in patients with breast cancer.

e13116 Background: Vascular emboli (VE) represent a critical event in breast cancer pathophysiology. Despite their clinical relevance, their relative impact on breast cancer outcomes remains underexplored. In this study, we delve into comparing the survival outcomes and recurrence rates of patients with and without VE in patients with breast cancer (BC) and adjust for other patient-related variables. Methods: This study was designed based on a retrospective cohort of pathologically confirmed de novo, local, or metastatic recurrence BC female patients diagnosed between 2020 and 2022 and aged > 18 years. Kaplan-Meier curves and Cox proportional hazards models were used to estimate the effect of vascular emboli on survival and recurrence while controlling other reviewed demographic, clinic, pathologic, and therapeutic features following a course of adjuvant or neo-adjuvant treatments. Results: A total of 501 patients were eligible for this study (216 patients without VE vs. 285 patients with VE). The median follow-up was 274 (IQR: 195–523) days. In the group of patients with positive VE, the median age at diagnosis was 49 years, and the median progression-free survival (mPFS) was 881 (95% CI: 856, 1555) days; Patients with bilateral BC have a poorer mPFS of 515 (95% CI: 411, Not Estimable NE), while right BC was associated with a better outcome of 1,035 (95% CI: 869, NE) days (p = 0.001). Moreover, patients with positive hormonal receptors (HR >=10%) who benefited from endocrine therapies have a better PFS of 974 (95% CI: 872, NE) days compared to those with negative HR (<10%) of 656 (95% CI: 586, NE) days (p = 0.02). In addition to the molecular profile, TNBC was associated with poorer survival 579 (95% CI: 553, NE), compared to RH-/HER2+ 675 (95% CI: 635, NE), RH+/HER2- 935 (95% CI: 777, NE), and RH+/HER2+ 1,133 (95% CI: 856, NE) days (p < 0.001). Surgery was associated with better mPFS (935 (95% CI: 869, NE) days compared to neo-adjuvant or palliative patients 856 (95% CI: 635, NE) (p = 0.002). In the group of patients with negative VE, the median age was 48 years. The mPFS was 852 (95% CI: 789–996) days. Patients presented with positive lymph (N2) have a worse PFS of 611 (95% CI: 505, NE) days; in addition, patients with HER2=0 have a worse PFS of 775 (95% CI: 595, 1,320) days compared to HER2 1+ or non-amplified HER2 2+ 928 (95% CI: 840, NE) days, while no statistically significant differences between patients who received different treatment options (HER2 TKI, chemotherapy, radiotherapy, and endocrine therapy) were found. Conclusions: These findings emphasize the importance of considering VE status and hormonal receptor expression in tailoring treatment strategies for BC patients. Identifying high-risk individuals who may benefit from aggressive or novel therapies remains crucial for improving outcomes. Further research is warranted to validate these results and guide clinical decision-making.