Management and Outcomes of Metastatic and Recurrent Malignant Phyllodes Tumors of the Breast: A Systematic Literature Review

To summarize the evidence on the current management and outcomes for metastatic and recurrent malignant phyllodes tumors (MPTs) of the breast. A systematic literature review of all cases of metastatic or recurrent MPTs of the breast published between 2010 and 2021 was performed. In total, 66 patients from 63 articles were included. Fifty-two (78.8%) had distant metastatic disease (DMD subgroup), and 21 (31.8%) showed locoregional recurrent/progressive disease (LRPR subgroup). Locoregional recurrences in patients with no distant metastases were treated with surgical excision in all cases. Radiotherapy was administered in 8/21 cases (38.1%) and was combined with chemotherapy in 2/21 cases (9.5%). Metastatic disease was managed through metastases surgical excision, chemotherapy, radiotherapy, or a combination of these three in 84.6% of cases, while the remaining patients received no oncological treatments. Chemotherapy was proposed in 75.0% of cases. Anthracycline and alkylating agent-based combination regimens were most frequently administered. The median survival time was 24 (2.0-152.0) months, and 72.0 (2.5-98.5) months in the DMD and LRPR subgroups, respectively. Management of recurrent or metastatic MPTs is challenging. Surgery is the fundamental approach, but the use of adjuvant radio- and chemo-therapy remains controversial due to the lack of scientific evidence. Further studies and international registers are needed to implement new and more efficient treatment strategies.