Primary breast sarcoma: A retrospective study over 35 years from a single institution. 
The aim of this study was to contribute to the collected knowledge of prognostic factors in primary breast sarcomas (PBS) to the benefit of possible future prospective studies and therapeutic guidelines.  All patients with pathologically verified PBS in the period of 1979-2014 were extracted from a hospital-based database at Aarhus University Hospital.  All records were reviewed for patient and tumor characteristics.  Primary endpoints were overall survival, disease-free survival (DFS) and disease-specific survival (DSS).  Adjustments were made for age, tumor location, surgical strategy, size, histological classification, prior radiation and grade.  Prognostic factors were determined by the use of Cox proportional hazard ratio.  In total 42 patients were identified.  Surgical resection was the main method of treatment.  Nineteen (45%) patients were initially selected for lumpectomy, of these 68% needed at least one re-excision to attain wide margins.  In total 55% experienced recurrence, loco regional in 43%.  Five-years overall survival was 49%, five-year DFS was 48% and five-year DSS was 40%.  Significant prognostic factors were size and grade.  A trend towards better survival in those with superficial tumors was observed as well as an increased incidence in radiation-induced angiosarcoma (AS) of the breast, however, prognosis was no different from non-radiation-induced AS.  Prognostic factors in PBS patients were size and grade with a trend towards better survival in those with superficial tumors.  There was no difference in survival between radiation-induced and spontaneous breast sarcomas.  High rate of local recurrence suggests the need for aggressive surgical approach or the routine addition of postoperative radiotherapy in those selected for breast conserving surgery (BCS).