Biologic distinctions and therapeutic implications of sarcomatoid metaplasia of epithelial carcinoma of the breast.

BACKGROUND: Malignant sarcomatoid metaplasia of epithelial carcinoma of the breast (carcinosarcoma) is diagnosed at an annual rate of two cases per 107 women in the United States of America. It seems that these tumors behave differently than other carcinomas or sarcomas of the breast. STUDY
DESIGN: The University of Texas M. D. Anderson Cancer Center experience (1947 to 1991) treating 50 patients (mean age of 50 years, range of 25 to 76 years) was retrospectively reviewed. The five-year overall survival and disease-free survival rates were compared and prognostic factors were identified.
RESULTS: The overall survival rate of 43 percent was lower than had been expected for carcinoma of the breast. No patient with stage IV disease survived five years. Tumor size and stage at diagnosis had the strongest impact on outcome. The impact of axillary lymph node status on prognosis was less than expected. Hormonal receptor levels were positive in only 12.5 percent of the tumors tested. Mastectomy with adjuvant chemotherapy or radiotherapy, or both, was superior to mastectomy alone and to wide local excision with or without adjuvant therapy, particularly for patients with stage II disease. If complete surgical resection is possible, the surgical approach for treatment of recurrent disease is better than any other modality.
CONCLUSIONS: Carcinosarcoma behave biologically differently than conventional carcinoma of the breast in that sarcomatoid characteristics dominate the clinical course. These biologic distinctions should direct the treatment toward a multimodality approach that includes mastectomy and sarcoma-oriented adjuvant chemotherapy and radiotherapy.