Angiosarcoma after breast-conserving therapy: long-term outcomes with hyperfractionated radiotherapy

With breast-conserving therapy (BCT) as the standard of care for patients with noninvasive and early stage invasive breast cancer, a small incidence of post-BCT angiosarcoma has emerged. The majority of therapeutic interventions have been unsuccessful. To the authors' knowledge, there is no consensus in the medical literature to date regarding the treatment of this malignancy. The current study was conducted to report the long-term outcomes of a novel approach using hyperfractionated and accelerated radiotherapy (HART) for angiosarcoma developing after BCT.

The authors retrospectively reviewed the outcomes of 14 patients treated with HART with or without surgery at the University of Florida between November 1997 and March 2006 for angiosarcoma that developed after BCT.

At the time of last follow-up, 9 patients had remained continuously without evidence of disease for a median of 61 months after HART (range, 36-127 months). Five patients had further manifestations of angiosarcoma after HART at a median of 1 month (range, 1-28 months): 3 with progressive pulmonary and/or mediastinal disease that was likely present before HART and 2 with local or regional disease extension. Progression-free survival rates for the 14 patients at 2 years and 5 years were 71% and 64%, respectively. The overall and cause-specific survival rates were both 86% at 2 years and 5 years.

To the best of the authors' knowledge, HART with or without subsequent surgery, as documented in the current series, is the first approach to provide a high rate of local control, disease-free survival, and overall survival after the development of post-BCT angiosarcoma. The authors believe the success noted with this approach is related to both the hyperfractionation and acceleration of the RT.