Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

UNLABELLED: The existing literature describing the clinicopathological features and behaviour of matrix-producing (MP) malignant breast tumours presents conflicting results. As a consequence it remains uncertain whether these tumours should be treated as sarcoma and managed by a specialist sarcoma team or treated using the same principles as conventional ductal carcinoma, a dilemma that prompted this study. Improved understanding of the clinicopathological characteristics of primary mammary MP-sarcomas, namely osteosarcoma and chondrosarcoma, is required. METHODS: In this large international multicenter series of malignant MP-tumours of the breast (no = 101) with follow-up information has been assessed and their outcome is compared to other subtypes of metaplastic breast carcinoma (MBC) (no = 253) and to grade, lymph node and hormone receptor-matched ductal breast carcinomas (no = 258). RESULTS: The majority of MP-cancers were associated with epithelial features, which supports the concept that the majority of, if not almost all, primary MP breast sarcomas are of epithelial in origin (MBC). 21% showed nodal metastasis and the distribution of distant metastases resembled conventional mammary carcinoma. The prognosis of MP-MBC is comparable to matched ductal breast carcinoma and slightly better than other subtypes of MBC. Advanced stage (T3&T4) and development of recurrences were predictors of shorter survival in MP-MBC while grade and vascular invasion were not. CONCLUSION: Most malignant MP breast tumours are variants of MBC. MP-MBC with predominant mesenchymal components behaves similar to ductal carcinomas and although data on their response to systemic therapy is limited, there is no evidence that they should be managed differently from other forms of triple negative breast cancer.

Original publication




Journal article



Publication Date





13 - 18


Adult, Aged, Aged, 80 and over, Breast Neoplasms, Chondrosarcoma, Combined Modality Therapy, Female, Follow-Up Studies, Humans, Lymphatic Metastasis, Metaplasia, Middle Aged, Neoplasm Grading, Neoplasm Recurrence, Local, Neoplasm Staging, Osteosarcoma, Prognosis, Survival Analysis