Radiation-induced sarcomas following radiotherapy for breast cancer: six case reports and a review of the literature

Seven patients with radiation-induced sarcomas (RIS) following radiotherapy (RT) for breast cancer were treated between 1983 and 1994 at the ‘Henri Mondor’ University Hospital (France). All patients underwent surgery and RT for breast cancer. Only one patient received chemotherapy (CT). All patients at the time of diagnosis of RIS were free of disease. Radiation-induced sarcoma appeared with a latency period varying from 5 years to 18 years (median, 11 years). The age of the patients ranged from 39 years to 88 years (median, 58.1 years) at the time of diagnosis of the sarcoma. The sarcomas occurred as follows: two in the treated breast, two in the chest wall, one in the preclavicular area and one in the axillary region. The histological types of sarcomas were: angiosarcoma (1), fibrosarcoma (2), osteosarcoma (1), malignant fibrous histiocytoma (MFH) (1), and highly malignant undifferentiated sarcoma (1). All six patients received treatment for their sarcoma: all underwent surgery, one had combined therapy of RT and CT, two patients in combination with CT, and one with immunotherapy also. Three patients are still alive. Two patients who died had local recurrence and metastatic disease. One had locally recurrent sarcoma only. Among the patients who are still alive, one has ovarian metastasis of breast cancer, one has local recurrence of sarcoma, and one is free of disease. The overall survival ranges from 14 months to 91 months (median, 32.6 months). Radiation therapy can induce malignancies after a latent period of several years. Radiation-induced sarcomas are associated with poor overall prognosis. The treatment in most cases is late and ineffective, and careful follow-up is needed. There are still many uncertainties and questions concerning RIS.