Abstract Background: Primary breast sarcomas are extremely rare malignant tumors that account for less than 1% of all breast malignancies. These tumors differ significantly from common breast carcinomas in terms of histogenesis, clinical behavior, and treatment approaches. Due to their low incidence, comprehensive data on clinicopathological characteristics and prognostic factors in female patients are limited. In this study, we evaluated the characteristics and prognostic features of female breast sarcoma patients. Method: Data for this study were obtained from the Surveillance, Epidemiology, and End Results (SEER) database, including female patients diagnosed with primary breast sarcoma, between 2000 and 2021. Demographic, clinicopathological, and survival data were analyzed to identify prognostic factors. Survival outcomes were evaluated using Kaplan-Meier analysis and multivariate Cox regression models. Results: A total of 4389 female breast sarcoma patients were identified from the database. A total of 2613 (59.5%) patients were under the age of 60. The five most common sarcoma types were malignant phyllodes tumor (58.4%), hemangiosarcoma (16.3%), carcinosarcoma (6.2%), sarcoma not otherwise specified (NOS) (3.7%), and spindle cell sarcoma (2.3%), respectively. The disease stages at diagnosis were localized (80.3%), regional (15.2%), and metastatic (4.5%), respectively. Surgical breast surgery was performed in 95.1% of the patients, 23.5% of patients received radiotherapy, and 14.9% of patients received chemotherapy. The 3-year, 5-year, and 10-year cancer-free survival rates were 82.3%, 79.1%, and 76.7%, respectively. The factors affecting prognosis were evaluated and in univariate analysis; age at diagnosis (p0.001), race (p=0.021), origin (p0.001), tumor side (p=0.590), sarcoma type (p0.001), disease stage (p0.001), surgery (p0.001), radiotherapy (p=0.003) and chemotherapy (p0.001) were determined. In multivariate analysis, age (p 0.001), stage at diagnosis (p 0.001), sarcoma type (p 0.001), and surgery (p 0.001) were identified as prognostic factors in breast sarcoma patients. Conclusion: Breast sarcomas are quite rare in women. According to the results of this study, cancer-specific deaths generally occur within the first 3 years. Age at diagnosis, sarcoma type, initial stage, and surgical treatment were determined as prognostic factors in breast sarcoma patients. Citation Format: A. Azizy, I. Dogan, O. Dülgeroğlu, S. Yücel, M. Bozkurt, I. Yıldız, A. Arican, I. D. Subası, C. Uras. Evaluation of Clinicopathological Features and Prognoses of Female Breast Sarcoma Patients abstract. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS4-08-17.
Azizy et al. (Tue,) studied this question.