Angiosarcoma of the breast after conservation therapy for invasive cancer, the incidence and outcome. An unforeseen sequela

Purpose. In the past 15 years breast conserving therapy (BCT) has become an important treatment option for primary breast cancer. Thirty three angiosarcomas (AS) after BCT have been described in a total of 20 published reports. Limited follow-up data and the lack of information on incidence of AS prompted the authors to review the comprehensive experience in the Netherlands. Methods. Between 1987 and 1995 twenty-one patients with BCT-associated AS were diagnosed in the Netherlands. Follow-up after diagnosis of AS ranged from 6 to 82 months with a median of 24 months. Information on the total number of patients treated with BCT and on the numbers of angiosarcoma in the breast was obtained. Results. The median interval between BCT and AS was 74 months (range: 29-106) and appeared to decrease with higher age. Detection of skin changes followed by incisional biopsy provided the diagnosis. Two year overall (OS) and disease free survivals were 72% (s.e. 10.9) and 35% (s.e. 10.7), respectively. Two year OS after initial complete surgical resection was 86% (s.e. 9.3) compared to 0% after incomplete resection of the AS (P = 0.04). The estimated incidence of AS after BCT is 0.16%. Conclusions. BCT-associated AS arises after a relatively short interval. Although the incidence of AS is low, the absolute number of patients at risk is increasing. This calls for vigilance concerning skin changes occurring after BCT. An incisional biopsy provides the only reliable diagnosis. The prognosis appears to be related to the completeness of surgical resection.