Primary female breast sarcoma: clinicopathological features, treatment and prognosis

Breast sarcoma, excluding phyllodes tumor, is an extremely rare and heterogeneous group of malignancies, constituting less than 1% of total breast malignancies and less than 5% of all soft tissue sarcomas (STS)1. It can be divided into two categories: de novo development (primary) or therapy-related development (secondary). Although clinical features of primary breast sarcoma (PBS) mimic mammary adenocarcinoma in some ways, it conveys a high risk of recurrence and carries a significantly worse prognosis. Due to its rarity, published literature is limited and confined to small retrospective case reviews and case reports. Optimal care is poorly-defined because information from previous studies is insufficient and inconsistent. In general, breast sarcoma is diagnosed by core or excisional biopsy. Staging is based on American Joint Committee on Cancer (AJCC) 7 for STS, which incorporates histologic grade (G), tumor size (T), node status (N), and distant metastases (M). There is no definitive consensus regarding PBS treatment, and current recommendations are derived from small retrospective case reviews and extrapolated from non-breast STS studies. Complete resection with negative margins (R0) is strongly recommended for curative intent. However, there is a debate of optimal surgical methodologies between breast conservative surgery (BCS) versus mastectomy. The role of radiotherapy and chemotherapy in non-metastatic PBS is also not clear. The current study utilizes a US population database to analyze a large series of women diagnosed with PBS. The primary objective was to determine clinicopathological characteristics of the PBS patient population and identify patient, pathologic, and treatment characteristics that predict survival outcomes.