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 beco me an important treatment option for primary breast cancer. Thirty thr ee angiosarcomas (AS) after BCT have been described in a total of 20 p ublished reports. Limited follow-up data and the lack of information o n incidence of AS prompted the authors to review the comprehensive exp erience in the Netherlands. Methods. Between 1987 and 1995 twenty-one patients with BCT-associated AS were diagnosed in the Netherlands. Fol low-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. Re sults. The median interval between BCT and AS was 74 months (range: 29 -106) and appeared to decrease with higher age. Detection of skin chan ges followed by incisional biopsy provided the diagnosis. Two year ove rall (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 re section was 86% (s.e. 9.3) compared to 0% after incomplete resection o f the AS (P = 0.04). The estimated incidence of AS after BCT is 0.16%. Conclusions. BCT-associated AS arises after a relatively short interv al. Although the incidence of AS is low, the absolute number of patien ts at risk is increasing. This calls for vigilance concerning skin cha nges occurring after BCT. An incisional biopsy provides the only relia ble diagnosis. The prognosis appears to be related to the completeness of surgical resection.