Soft tissue sarcomas after radiation treatment for breast cancer. Three case studies and review of literature.
AIMS: By means of 3 cases with infield soft tissue carcinomas after radiotherapy for breast cancer, symptoms and therapy are described. Consequences for treatment planning and patient's information before radiotherapy for breast cancer are discussed. PATIENTS: Three of 1,025 patients with breast cancer irradiated from 1984 to 1997 suffered from infield secondary soft tissue sarcomas. The latency periods were 61, 49 and 59 months. Two patients had been treated with breast-conserving therapy (computerized planning, 50 Gy to reference point, 5 times 2 Gy/week, 5-MV photons), 1 patient received a local boost dose of 15 Gy (10-MeV electrons), patient 3 radiotherapy of the thoracic wall and regional lymph nodes after mastectomy using 12-MeV electrons (thoracic wall) and 5-MV photons (lymph node areas) to 50 Gy, 5 times 2 Gy/week. No adjuvant chemotherapy was given. All sarcomas were very extensive, all patients died from local progression and/or distant failure after 17, 13 and 12 months. RESULTS: The incidence of spontaneous sarcomas of the breast is about 0.06%, after operation and radiotherapy 0.09 to 0.45%. No correlations to radiotherapy technique and no risk factors were found. Radiation dose could play a role, but there are very sparse data about this. CONCLUSIONS: Secondary soft tissue sarcomas are very rare, but familiar complications of radiotherapy. Only early diagnosis leads to a chance for cure. Because of unclear correlations to the treatment parameters and rareness of this event, in our opinion no regular information to the patient receiving radiotherapy for breast cancer is mandatory.