Abstract P6-09-41: Factors predicting treatment outcomes of angiosarcoma of breast: A 25 year single institution experience

Abstract

Abstract Background: Primary (PAS) and secondary angiosarcoma (SAS) of breast account for < 1% of all breast neoplasms. SAS develops following radiation therapy (RT) to the breast or chest wall for treatment of breast cancer. The rarity of this tumor type makes it challenging to determine prognostic factors and develop optimal treatment strategies. Historically, large NCI cancer centers have reported a median overall survival ranging from 28 – 100 months with recurrence rate of 55%. Methods: We reviewed demographic, tumor, and treatment characteristics of breast AS patients diagnosed and treated at our institution between 1990 and 2015. Overall (OS) and recurrence free (RFS) survival were compared using standard statistical methods at a significance level of 0.05. Results: Of 12155 breast cancers, 22 patients (0.008%) with AS (PAS in 34%, SAS in 66%) were identified. Median age of PAS patients was significantly lower than SAS – 45 vs 71 years (p < 0.001). Median tumor size was 6.9 cm (7.3 cm vs 6.9 cm, p = 0.93) with multifocal disease seen in 22.7%. Tumor was high grade in 14 (50% vs 83.3%, p = 0.34). Median time from RT to SAS diagnosis was 7.8 years. Treatment included: mastectomy in 17 (77.3%), wide excision in 4 (18.2%), adjuvant RT in 4 (18.2%), taxane based chemotherapy in 11 (50%) and chemo-RT in 1 (4.5%). No significant differences were noted in tumor (p = 0.9) or treatment characteristics (p = 0.4) between PAS and SAS. Recurrence rate (mainly distant) was 36% (8 pts). The 5-year OS and RFS rates were 51% (95% CI 27–72%) and 36% (95% CI 14–58%) with estimated medians of 64.2 and 55.5 months, respectively with no significant difference between the two groups. Black ethnicity (11.6 vs 64.2 months, p = 0.015), multifocal disease (15.5 vs 64.2 months, p = 0.004) and tumor size of > 6.9 cm (8.3 vs 64.2 months, p = 0.03) were associated with poorer outcomes. Tumor grade was not related to OS. Adjuvant treatment (RT p = 0.49, chemotherapy p = 0.36) conferred no RFS or OS benefit. Conclusions: Patients with PAS were younger than SAS. Black race, multifocal presentation and larger tumor size predict worse clinical outcomes. Our institutional experience confirms the poor prognosis of angiosarcoma, and highlights the need for further research. Citation Format: Ammannagari N, Attwood K, Cheney R, Young JS, Kane JM, Salerno KE, Opyrchal M. Factors predicting treatment outcomes of angiosarcoma of breast: A 25 year single institution experience [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-41.