Angiosarcoma in the breast: a population-based cohort from Sweden

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Breast angiosarcoma is a rare malignancy.
• It predominantly affects patients with a history of breast cancer (BC) treated with radiotherapy (RT).
• Limited data exists on angiosarcoma etiology, management, and outcomes.

Purpose of the Study:

• To estimate the risk of breast angiosarcoma in a population-based cohort.
• To characterize the clinical features, management, and outcomes of breast angiosarcoma.
• To investigate the association between prior breast cancer radiotherapy and angiosarcoma development.

Main Methods:

• A population-based cohort study was conducted in three Swedish healthcare regions (2018 population: 5.5 million).
• Data on breast angiosarcoma cases were retrieved from the Swedish Cancer Registry (1992–2018).
• Medical records were reviewed for details on previous BC, RT, treatment, and patient outcomes.

Main Results:

• 49 breast, chest wall, or axillary angiosarcomas were identified; 8 primary and 41 secondary to BC treatment.
• Secondary angiosarcomas occurred 4–21 years after BC diagnosis, with cumulative incidence increasing with time post-RT.
• Median recurrence-free survival was 3.4 years for primary and 1.8 years for secondary angiosarcoma; 5-year overall survival was 50% for primary and 35% for secondary cases.

Conclusions:

• Breast angiosarcoma is a rare but serious condition, strongly associated with prior breast cancer radiotherapy.
• Outcomes are generally poor, characterized by high rates of local recurrence and distant metastasis.
• Further research is needed to improve the management and survival of patients with breast angiosarcoma.