Annals of Surgical Oncofogy 1(1):6672 Published by Raven Press, Ltd. © 1994 The Society of Surgical Oncotogy, Inc. Post-Treatment Sarcoma in Breast Cancer Patients Mary S. Brady, MD, Carol F. Garfein, MBA, Jeanne A. Petrek, MD, and Murray F. Brennan, MD Background: Many patients treated for breast cancer with radiotherapy wilt survive their disease and be at risk for treatment-related sarcoma for many years. Methods: In order to identify patients with post-treatment sarcoma and de- fine this disease, we examined the records of 99 patients treated for sarcoma with a history of antecedent breast carcinoma. Of these patients, 51 were felt to have a sarcoma unrelated to breast cancer treatment and 48 were felt to have a treatment-related sarcoma (secondary to lymphedema and/or radiation). Results: Lymphangiosarcoma of the extremity was the most common histo- logic subtype of post-treatment sarcoma, accounting for 22 of 48 cases (46%). Twenty-six patients (54%) developed nonlymphangiosarcoma post-treatment sarcoma; all of these were radiation-associated sarcomas. The median latency interval between the diagnosis of breast cancer and the development of sar- coma was 11 years (range 4-44) and was not different between the two groups. However, patients with nonlymphangiosarcoma were significantly younger when diagnosed with breast cancer than were those with lymphangiosarcoma of the extremity (median 43 vs. 51 years, p < 0.001). The survival of all 48 patients was poor: 5-year survival was 29%. Five-year survival of patients with other types of post-treatment sarcoma was just as poor as those with lymphan- giosarcoma of the extremity (30% vs. 28%, p = 0.98). Conclusions: Patients who develop sarcoma after treatment for breast cancer have a poor prognosis whether it occurs as Stewart-Treves syndrome or other types of post-treatment sarcoma. Younger patients may be at higher risk than are older patients for the development of nonlymphangiosarcoma post- treatment sarcoma. Key Words: Sarcoma--Breast cancer--Radiation--Lymphangiosarcoma. Although postmastectomy lymphangiosarcoma of the extremity is a well-known consequence of breast cancer treatment, other post-treatment sar- comas have received far less attention. In a recent report from our institution, breast cancer was the most common antecedent malignancy in patients Received March 30, 1993; accepted July 21, 1993. From the Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A. (M.S.B., J.A.P., M.F.B.). Ms. Garfein is a medical student at Mt. Sinai School of Medicine, New York, New York, USA. Address correspondence and reprint requests to Dr. Mary S. Brady, Memorial Sloan-Kettering Cancer Center, 1275 York Av- enue, New York, NY 10021, USA. Presented at the 46th Annual Cancer Symposium of the Soci- ety of Surgical Oncology, Los Angeles, March 18-21, 1993. who developed radiation-associated sarcomas, comprising 26% of the group (1). As part of an ongoing project in soft tissue sar- coma at our institution, we reviewed our experience with post-treatment sarcoma in breast cancer pa- tients. Our goals were to define the clinical presen- tation and determine the survival of patients with this disease. In addition, we were interested in iden- tifying factors that may predispose patients to the development of a post-treatment sarcoma and to identify clinical or pathologic factors associated with survival. PATIENTS AND METHODS We reviewed the records of patients treated at Memorial Sloan-Kettering Cancer Center (MSKCC), 66