Spindle cell carcinoma of the breast: a comprehensive analysis

Breast spindle cell malignancies are rare. No standard treatment exists.The Surveillance, Epidemiology, and End Results database was used to identify patients with breast spindle cell malignancies, 1992 to 2011. Descriptive statistical analysis and survival analysis were performed.A total of 286 patients were identified (98.6% female). Approximately, 15% had estrogen receptor-positive tumors and 12.5% had progesterone receptor-positive tumors. Nearly 38% underwent partial mastectomy, whereas 55.5% underwent mastectomy. The frequency of partial mastectomy has increased in more recent years. One-third received radiation. Lymph node metastases were infrequent (9.3%) and distant metastases were uncommon (6.1%). Ten-year survival rates for patients with early-stage (I and II) disease were 83.9% after partial mastectomy, 86.7% after partial mastectomy plus radiation, and 71.6% after complete mastectomy. Three-year survival rates for patients with late-stage (III and IV) disease were low with 40.0% after complete mastectomy and 0% after complete mastectomy plus radiation.This nationally representative analysis demonstrates that early-stage spindle cell carcinoma of the breast is adequately treated by partial mastectomy. Radiation may be considered for small, potentially early survival benefit. For late stage disease, complete mastectomy is appropriate; however, survival is poor, and radiation contributes no significant additional benefit.