Long-term risk of sarcoma following radiation treatment for breast cancer

At the hospital de la Santa Creu i Sant Pau, Barcelona, Spain, 3,120 patients with breast carcinoma were submitted to radiation between 1976 and 1994. Among them there were three patients (0.06%) in whom malignant neoplasm developed in areas of prior irradiation. Histologically, the three tumors were postirradiation sarcomas (PIS): 2 osteogenic sarcomas and one angiosarcoma. The radiation doses varied between 46 and 50 Gy. One patient additionally received chemotherapy. The median interval that transcurred between the start of radiation therapy and the detection of the new growth was 14.3 years. One patient is still alive and in treatment. The other two patients died of sarcoma, 1 and 12 months after the diagnosis of PIS. Taking into account the unfavourable outcome of these three cases, we want to emphasize that the benefit of postsurgical radiation therapy in breast cancer patients by far exceeds its risk of causing a second malignant growth.