Angiosarcoma after breast-conserving therapy: long-term disease control and late effects with hyperfractionated accelerated re-irradiation (HART).

BACKGROUND: Secondary angiosarcoma is a malignant cancer that develops in approximately 1% of patients treated with breast-conserving therapy (BCT) for primary breast cancer. Most treatments for secondary angiosarcoma have been unsuccessful and no consensus has been reached on what is the best therapeutic strategy. We report long-term outcomes of patients with secondary angiosarcoma treated with hyperfractionated and accelerated re-irradiation (HART).
MATERIAL AND METHODS: We retrospectively reviewed the medical records of, and established direct contact with, 14 consecutive patients with secondary angiosarcoma after BCT with axillary lymph node dissection who were treated at our institution with HART with or without surgery from November 1997 to March 2006. With HART, patients received three radiation therapy treatments each day, with a minimum interfraction interval of four hours, five days a week, at 1 Gy per fraction, to total doses of 45 Gy, 60 Gy, and 75 Gy for areas with a moderate risk for subclinical disease, a high risk for subclinical disease, and gross disease, respectively. The minimum follow-up for these patients was six years.
RESULTS: Median survival was 7.0 years (range 0.4-14.7 years), with five- and 10-year overall survival rates of 79% [95% confidence interval (CI), 51-93%] and 63% (95% CI 37-84%), respectively, and five- and 10-year cause-specific survival rates of 79% (95% CI 51-93%) and 71% (95% CI 44-89%), respectively. Toxicity was minimal.
CONCLUSION: Our long-term study provides evidence that patients with secondary angiosarcoma after BCT can frequently be cured. Patients treated with HART have higher overall survival, progression-free survival, and cause-specific survival rates than patients who receive only surgery, conventional radiation therapy, or chemotherapy. HART is well tolerated.