Clinicopathological characteristics, treatments and oncological outcomes in metaplastic breast cancer: a Brazilian multicenter analysis

MBC presented as a large nodular lesion at diagnosis, the most frequent metaplastic subtypes presented squamous and mesenchymal differentiation, almost 80% were triple-negative tumors, however, responses to neoadjuvant chemotherapy can be considered poor. A higher number of metastatic lymph nodes and larger tumor size were associated with worse DFS and OS, meanwhile the women who undergone to adjuvant chemotherapy showed better DFS and OS. Furthermore, most recurrences occurred in the first 24 months of follow-up, stabilizing at approximately 50% after 36 months, and most deaths occurred in the first 36 months, stabilizing thereafter, which is a clinical pattern of very aggressive tumors.