Retrospective cohort study of treatment-related thoracic soft tissue sarcomas in breast cancer survivors

Soft tissue sarcoma (STS) is a rare but serious side-effect of therapy for breast cancer. A retrospective study in two cohorts of breast cancer survivors in the USA found that radiotherapy was the strongest risk factor for thoracic STS, although there was no association with prescribed dose, fractionation, or boost. There was an increased risk of angiosarcoma after anthracyclines and of other sarcomas after alkylating agents. History of hypertension and diabetes were associated with increased risk of angiosarcoma.